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Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 170
CHAPTER.6
FORMULATION AND EVALUATION OF FAST DISSOLVING TABLET OF
ONDANSETRON HCl
6.1 Taste making of ondansetron HCl
6.1.1 Development and characterization of taste masked granules of
ondansetron HCl
6.1.1.1 Preparation of drug polymer complex
The drug polymer complex (DPC) was prepared by using different ratio (1:1, 1:3, 1:5)
of ondansetron HCl and Eudragit® EPO. A gel containing ondansetron HCl and Eudragit® EPO
was prepared by gradual addition of 10 % ethanol using a mechanical stirrer in a glass
beaker. The gel was manually extruded through a syringe. The ethanol was evaporated by
keeping the extrudates overnight at room temperature. The solidified gel in the shape of
string was crushed and sieved through sieve sized 280 μm to make the granules.
6.1.1.2 Characterization of drug polymer complex
In-Vitro taste evaluation
The drug polymer complex (DPC) containing 10 mg of ondansetron HCl were mixed
with 10 ml of phosphate buffer (pH 6.8)in a 10 ml syringe by revolving the syringe end to
end for 60 seconds. Thereafter solution of ondansetron HCl was filtered and amount of drug
release was determined spectrophotometrically at 249 nm.
Drug content
DPC equivalent to 10 mg of drug was stirred by using magnetic stirrer with 100 ml of
0.1 N HCl for 60 minutes, till the entire drug leached out from complex, than the solution
was filter through whatman filter paper. Further solution was diluted with 0.1 N HCl and the
drug content was determined spectrophotometrically at 249 nm.
Thermal analysis
DSC analysis was performed using Netzsch DSC 204, Tokyo, Japan. The samples were
heated in a sealed aluminium pans at a rate of 100 °C per min in a 30 to 3000 °C
temperature under nitrogen flow of 40 ml/min.
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 171
Fourier Transform Infrared (FTIR) Spectroscopy
FTIR spectra were obtained on Shimadzu FTIR Model 8400-S spectrometer. The
spectra was recorded as a dispersion of the sample in potassium bromide in IR disk (2 mg
sample in 200 mg KBr) with the scanning range of 400 to 4000 cm-1 and the resolution was
1 cm -1.
X-ray Diffraction (XRD) studies
X-ray Diffraction analysis was carried out to evaluate the degree of crystallinity. The
pure ondansetron HCl, pure Eudragit EPO, and drug polymer complex (1:5) were subjected
topowder XRD (P.W. 1729, X-Ray Generator, Philips, Netherland) at 2θ angles between 200
and 380 in increments of 0.40.
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 172
6.2 Design and optimization of FDT of ondansetron HCl using different
ratio of mcc and lactose
6.2.1 Preparation of tablet
Fast dissolving tablets of ondansetron HCl were prepared by direct compression
method. All the raw materials were passed through a # 60 sieve prior to mixing. Drug
polymer complex (1:5), containing amount equivalent to 10 mg of ondansetron HCl, was
mixed with the other excipients. The powder blend was lubricated with magnesium stearate
and compressed on a 10 station mini press tablet machine (CPMD 3-10, Chamunda Pharma
Machinery Pvt. Ltd., Ahmedabad, India.) equipped with 9 mm concave punch. Composition
of tablets is shown Table 6.1.
Table 6.1 Composition of fast dissolving tablet
Ingredient Value (%)
DPC 24
Ac-Di-Sol 2-6
MCC 0-70
Lactose 100-30
Mag. Stearate 1.5
Saccharine sodium 0.6
Tablet weight=250 mg
6.2.2 Optimization of formulation
Optimization technique based on response surface methodology was utilized.
Response surface methodology can be defined as a statistical method that uses quantitative
data from appropriate experiments to determine and simultaneously solve multivariate
equations. It is generally used to determine the optimum combination of factors that yield a
desired response and describes the response near the optimum. This methodology was
used in the present study to optimize the variables affecting the formulation.
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 173
Statistical design
A randomized 3 level full factorial design using two factors was adopted to
systematically study the formulation of FDT of ondansetron HCl. A total of 12 experimental
run with 3 centre points were performed at all possible combination. The independent
variable, were selected on the basis of trials taken during preliminary batches. The
disintegration time and hardness were selected as dependent variable. Different variables
used in full factorial design are shown in Table 6.2. Matrix design for different experimental
run is shown in Table 6.3.
Analysis of response
Response were analysed by Analysis of variance (ANOVA), to identify the
insignificant factors, which were then removed from the full model to generate the reduced
model.
Table 6.2 Variables in 3 level full factorial design
Independent variables-Factor Levels (%)
Low (-1)
Middle (0)
High (+1)
X1= MCC in MCC- Lactose combination 30 50 70
X2= Ac-Di-Sol Concentration 2 4 6
Dependent variable- Response
Y1= Disintegration time (seconds)
Y2= Hardness (kg/cm2)
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 174
Table 6.3 Layout of full factorial design
Batch X1: %MCC in Lactose/MCC:Lactose combination
(%) X2: Ac-Di-Sol(%)
OH 1 1 -1
OH 2 0 0
OH 3 -1 0
OH4 0 0
OH5 0 -1
OH6 -1 -1
OH7 0 0
OH8 1 1
OH9 -1 1
OH10 1 0
OH11 0 0
OH12 0 1
Validation of statistical model
Levels of factors were selected at different points and responses predicted by the
statistical models were calculated. Tablets were prepared using these levels and responses
were measured practically. The predicted responses were compared against observed
responses and closeness between them was checked.
Response surface plots
Response surface plots were generated for each response to study the effect of both
factors on each response.
Different constraints were applied (Table 6.4) and on the basis of confirmation
report (Two-sided, Confidence = 95%, n = 1) as shown in Table 6.5, tablets were
prepared.
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 175
Table 6.4 Constraints
Name Goal Lower Limit
Upper Limit
X1:MCC in Lactose/MCC:Lactose comination is in range -1 1
X2:Ac-Di-Sol is in range -1 1
DT Target=25 22 38
Hardness Target=4.5 4 4.5
Table 6.5 Confirmation Report (Two-sided, Confidence = 95%, n = 1)
Factor Name Level Low Level
High Level
Std. Dev.
Coding
X1 MCC in Lactose/MCC:Lactose
comination 66 30 70 0.000 Actual
X2 Ac-Di-Sol 4.9 2 6 0.000 Actual
6.2.3 Preparation of optimized batch (OFDT1)
Optimized batch was prepared as method discussed earlier. The formula for
optimized batch (DFDT2) shown in Table 6.6.
Table 6.6 Composition of optimized Batch
Ingredients Quantity (%) Quantity (mg)
DPC 24 60
Ac-Di-Sol 4.9 11
MCC:lactose 66:34 114.4:58.9
Mag. Stearate 1.5 3.75
Saccharine sodium 1 0.6
Tablet weight= 250 mg
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 176
6.3 Design and optimization of fast dissolving tablets of ondansetron HCl
using vacuum-drying approach
6.3.1 Preparation of tablets
Composition of fast dissolving tablets is mentioned in Table 6.7. All the raw materials
were passed through a 60 # sieve prior to mixing. Drug polymer complex (1:5), containing
amount equivalent to 10 mg of ondansetron HCl, was mixed with the other excipients. The
powder blend was lubricated with magnesium stearate and compressed on a 10 station mini
press tablet machine (CPMD 3-10, Chamunda Pharma Machinery Pvt. Ltd., Ahmedabad,
India.) equipped with 9 mm concave punch. The tablets were dried in a vacuum oven for 4 h
at a temperature of 60 0C and at a pressure of 300 mm Hg.
Table 6.7 Composition of fast dissolving tablet
Ingredients Quantity (%)
DPC 24
Camphor 0-40
Mannitol 10-50
Mag. Stearate 1.5
Lactose q. s. to 250
Tablet weight=250 mg
6.3.2 Optimization of formulation
Optimization technique based on response surface methodology was utilized.
Response surface methodology can be defined as a statistical method that uses quantitative
data from appropriate experiments to determine and simultaneously solve multivariate
equations. It is generally used to determine the optimum combination of factors that yield a
desired response and describes the response near the optimum. This methodology was
used in the present study to optimize the variables affecting the formulation.
Statistical Design
A randomized 3 level full factorial design using two factors was adopted to
systematically study the formulation of FDT of ondansetron HCl. A total of 12 experimental
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 177
run with 3 centre points were performed at all possible combination. The independent
variable, were selected on the basis of trials taken during preliminary batches. The
disintegration time and hardness were selected as dependent variable. Different variables
used in full factorial design are shown in Table 6.8. Matrix design for different experimental
run is shown in Table 6.9.
Table 6.8 Variables in 3 level full factorial design
Independent variables-Factor Levels (%)
Low (-1)
Middle (0)
High (+1)
X1= Mannitol 30 40 50
X2= Camphor 10 20 30
Dependent variable- Response
Y1= Disintegration time (seconds)
Y2= Hardness (kg/cm2)
Table 6.9 Layout for full factorial design
Run X1: Mannitol (%) X2: Camphor (%)
OV 1 -1 -1
OV 2 0 0
OV 3 0 0
OV4 0 -1
OV5 1 0
OV6 1 1
OV7 0 0
OV8 0 1
OV9 -1 1
OV10 0 0
OV11 -1 0
OV12 1 -1
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 178
Analysis of response
Response were analysed by Analysis of variance (ANOVA), to identify the
insignificant factors, which were then removed from the full model to generate the reduced
model.
Validation of statistical model
Levels of factors were selected at different points and responses predicted by the
statistical models were calculated. Tablets were prepared using these levels and responses
were measured practically. The predicted responses were compared against observed
responses and closeness between them was checked.
Response surface plots
Response surface plots were generated for each response to study the effect of both
factors on each response.
Different constraints were applied (Table 6.10) and on the basis of confirmation
report (Two-sided, Confidence = 95%, n = 1) as shown in Table 6.11, tablets were
prepared.
Table 6.10. Constraints
Name Goal Lower Limit Upper Limit
X1:Mannitol In range -1 1
X2:Camphor In range -1 1
Hardness Target=4 1.2 4.9
DT Target = 32 8 35
Table 6.11. Confirmation Report (Two-sided, Confidence = 95%, n = 1)
Factor Name Level Low Level High Level Std. Dev. Coding
X1 Mannitol 38 30 50 0.000 Actual
X2 Camphor 13 10 30 0.000 Actual
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 179
6.3.3 Preparation of optimized batch (OFDT2)
Optimized batch was prepared as method discussed earlier. The formula for
optimized batch (DFDT2) shown in Table 6.12.
Table 6.12 Composition of optimized batch (OFDT2)
Ingredients Quantity (%) Quantity (mg)
DPC 24 60
Camphor 13 32.5
Mannitol 38 95
Mag stearate 1.5 3.75
Lactose Qs to 100 % Qs to 100 %
6.4 Evaluation of fast dissolving tablets of ondansetron HCl
6.4.1 Pre-compression characterization
The quality of tablet was generally dictated by the quality of physicochemical
properties of blends. There were many formulations and process variables involved in
mixing steps all these can affect the characteristic of blend produced. The characterization
parameters for evaluating the flow property of mixed blends includes bulk density, tapped
density, Hausner’s ratio, compressibility index and angle of repose.
Bulk density
Apparent bulk density (ρb) was determined by pouring the blend in to a graduated
cylinder. The bulk volume (Vb) and weight of powder (M) was determined [160-163]. The
bulk density was calculated using the formula:-
Tapped density
The measuring cylinder containing a known amount of tablet blend was tapped 100
times using density apparatus. The constant minimum volume (Vt) occupied in the cylinder
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 180
after tapping and the weight (M) of the blend was measured [160-163]. The tapped density
(ρt) was calculated using formula
Compressibility index
Compressibility is the simplest way for the measurement of powder flow property. It
is an indication of ease with which a material can be induced to flow [160-163]. it is
expressed as compressibility index (I), which can be calculated as follows:-
Where, ρt = Tapped density; ρb = bulk density
Limits for compressibity index are shown in Table 6.13.
Table 6.13 Compressibility index as an indication of powder flow properties
Compressibility Index (%) Type of flow
>12 Excellent
12-16 Good
18-21 Fair to passable
23-35 Poor
33-38 Very poor
>40 Extremely poor
Hausner’s ratio
Hausner’s ratio (HR) is an indirect index of ease of powder flow. It was calculated by
the following formula:-
Where, ρt = Tapped density; ρb = bulk density
Lower Hausner’s ratio (<1.25) indicates better flow properties than higher ones [160]
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 181
Angle of repose
Angle of repose was determined using the funnel method. The blend was poured
through a funnel that can be raised vertically until a specified cone height (h) was obtained.
Radius was measured and angle of repose was determined using the formula [164-166].
Therefore,
(
)
Where, θ is angle of repose; h is the height of cone; r is radius of cone.
Limits of angle of repose are shown in Table 6.14.
Table 6.14 Angle of repose as an indication of powder flow properties
Angle of repose(θ) Type of flow
<25 Excellent
25-30 Good
30-40 Passable
>40 Very poor
6.4.2 Post compression characterization
After compression, the prepared tablets were evaluated for organoleptic
characteristics like color, taste, odor, diameter, thickness and physical characteristics like
hardness, friability, disintegration time, wetting time.
General appearance
The general appearance of a tablet, its visual identification and over all elegance is
essential for consumer acceptance. This include tablet’s size, shape, odor, color, taste,
surface texture etc [167]
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 182
Tablet thickness
Tablet thickness is an important characteristic in reproducing appearance and also in
counting by suing filling equipment. Some filling equipment utilizes the uniform thickness of
the tablets as a counting mechanism. Thickness of tablets was recorded using micrometer
(Mityato, Japan).
Weight variation
The weight variation test would be satisfactory method of determining the drug
content uniformity. As per USP [168], twenty tablets were taken and weighted individually.
Average weight was calculated and compared the individual weight to average weight.
Weight variation limits are given in Table 6.15.
Table 6.15 Weight variation limit for tablets as per USP
Average weight of tablet (mg) Maximum % difference allowed
130 or less 10
130-324 7.5
More than 324 5
Hardness
Hardness of the tablet is defined as the force applied across the diameter of the
tablet in order to break the tablet. The resistance of the tablet to chipping, abrasion or
breakage under condition of storage transformation and handling before usage depends on
its hardness. Hardness of the tablet of each formulation was determined using Pfizer
Hardness taster [167-169].
Friability
Friability of tablets was determined using Roche friabilator apparatus. This device
subjects the tablet to the combined effect of abrasion and shock in a chamber, revolving at
25 rpm and dropping the tablet at the height of 6 inch in each revolution. Pre-weighed
sample of tablets was placed in the friabilator and were subjected to 100 revolutions.
Tablets were dedusted using a soft muslin cloth and reweighed. The friability (F %) was
determined by the formula
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 183
Where, W0 is the initial weight of the tablets before the test and W is the weight of the
tablet after test [167,170]
Drug content
The test is obligatory for tablets containing less than 10 mg or less than 10 % w/w of
active ingredient. This test was performed as per Indian Pharmacopoeia, 1996. A tablet was
crushed and dissolved 1 ml of dilute hydrochloric acid and 30 ml of distilled water. This
solution was shaken for 15 min. the volume of this solution was made up to 50 ml with
distilled water and centrifuged. Five milliliters of the clear supernatant was mixed with 10
ml of 0.1 N HCl, and made up to 100 ml with distilled water. The absorption of the solution
was determined spectrophotometrically at 249 nm. The same procedure was followed for
another nine tablets.
Disintegration time
The disintegration time was measured using a modified disintegration method.
According to this method, a petri dish of 10-cm diameter was filled with 10 mL of phosphate
buffer pH 6.8, the tablet was carefully placed at the center of the petri dish, and the time
necessary for the complete disintegration of the tablet into fine particles was noted as
disintegration time [171].
Wetting time
A piece of tissue paper folded twice was kept in a culture dish (internal diameter 5.5
cm) containing 6 mL of purified water. A tablet having a small amount of amaranth powder
on the upper surface was placed on the tissue paper. The time required to develop a red
colour on the upper surface of the tablet was recorded as the wetting time [172].
Dissolution studies
Tablet test condition for the dissolution rate studies were used according USP
specification using USP 24, type II apparatus. The dissolution medium was 900 ml of 0.1 N
HCl (pH 1.2). The temperature of the dissolution medium and the rate of agitation were
maintained at 37± 0.50 °C and 50 rpm respectively. Aliquots of 10 ml of dissolution medium
were withdrawn at specific time interval and the volume replaced by fresh dissolution
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 184
medium, pre warmed to 37± 0.50 °C. The drug concentration was determined
spectrophotometrically at 249nm using UV spectrophotometer (Shimadzu S 1800, Japan).
Scanning electron microscopy (SEM)
The optimized tablet was also observed by scanning electron microscope (ESEM TMP
with EDAX, Philips, Holland). Pictures were taken at an excitation voltage of 30 kv and a
magnification of 120 X.
6.5 In vivo study for optimized ondansetron HCl fast dissolving tablet
6.5.1 Pharmacokinetic Studies
Sample preparation
In a 10 ml capacity glass tube, 1 ml plasma was mixed with 50 µl of saturated sodium
carbonate solution and 5 ml of dichloromethane and mixture was stirred by rotary mixer for
15 min at room temperature. The mixture was centrifuged for 5 min at 5000 rpm and 4.5 ml
of the organic phase was transferred into another test tube and evaporated to dryness at
40°C under a stream of nitrogen. The residue was reconstituted in 100 µl of mobile phase
and a volume of 20 µl was injected into the HPLC for analysis [204].
Seven-week-old male wistar rats were used in the present experiment. Their mean
weight was 264.66 ± 8.96 g in the range of 259-275 g. Animals were housed in a room
maintained on a 12 hrs light/dark cycle at 23±2 °C with free access to food and water.All the
animal experiments were performed according to the guideline of local animal ethical
committee (Ref no- BU/BT/185/11-12). The Test (OFDT 1) formulation and Reference
(Ondem MD) were administered to the rats by gastric intubation method after calculating
the animal dose [174]. Blood samples were withdrawn after 0, 0.50, 1, 2, 4 and 6 hrs. from
different animals at each time (n=3).
Pharmacokinetics and statistical analyses
The following pharmacokinetics parameters were calculated using non-
compartmental methods: area under the plasma concentration–time curve from zero to the
last measurable Ondansetron concentration sample time (AUC0-t), area under the plasma
concentration–time from zero extrapolated to infinite time AUC0-∞, maximum plasmatic
drug concentration (Cmax) and time to reach Cmax(tmax), terminal rate constant (Kel) and
terminal half-life (t1/2). Cmax and tmax were obtained directly from the concentration–time
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 185
curve. AUC0–t was calculated using the linear trapezoidal method. Kel was calculated by
applying a log-linear regression analysis to at least the last three quantifiable concentrations
of ondansetron; t1/2 was calculated as 0.693/Kel [175].
For the purpose of bioequivalence analysis AUC0–t, AUC0–∞and Cmax were considered
as primary variables. Bioequivalence between the products was determined by calculating
90% confidence intervals (90% CI) for the ratio of Cmax, AUC0–t and AUC0–∞ values for the test
and reference products, using logarithmic trans-formed data. Analysis of variance (ANOVA)
was used to assess product, group and period effects. The products were considered
bioequivalent if the 90%CI for AUC0–t andC max fell within 80–125%.
6.5.2 Pharmacodynamic Study
Method
As discussed earlier.
6.5.3 General procedure
Behavioral testing was always conducted during the same period of the day. The
procedure was performed in three consecutive phases.
Pre-conditioning phase
This phase consisted of three consecutive days. Animals were subjected individually
to the apparatus in untreated condition with the guillotine doors open for 15 min per trial.
After the third baseline trial the preference for one of the two compartments was calculated
by taking the mean time spent in the compartments over the three baseline trials.
Conditioning phase
The mice were assigned randomly to the treatment groups (vehicle, lithium sulphate
(160 mg/kg), Zofer MD (10 mg/kg), Ondem MD (10 mg/kg) and OFDT1 (10 mg/kg) with
lithium sulphate, in a volume of 5 mL/kg body weight). The mice were treated with the
conditioning drug on one day and the vehicle on the alternate day. Each mice was exposed
to an equal number of drug pairings with both the compartments. The treatment lasted for
8 days (four pairings).
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 186
Post-conditioning phase
On the day following the conditioning phase, drugs were not administered to
animals and they were placed in the apparatus with the doors open and the time spent in
the preferred compartment was recorded during the 15 min test session.
Experimental set up for the study is shown in Table 6.16.
Table 6.16 Experimental setup for ondansetron HCl
Group Treatment
Group I Treated with vehicle
Group II Treated with Lithium sulphate
Group III Treated with Comp I (Zofer- MD, Sun Pharmaceutical Ltd) + Lithium
sulphate
Group IV Treated with Comp II (Ondem-MD 8, Alkem Laboratories Ltd.) + Lithium
sulphate
Group V Treated with Comp III (OFDT 1) + Lithium sulphate
6.6 Stability study
6.6.1 Selection of fast dissolving tablets
The results of tablet characterizations of different batches were compared and
optimized batch OFDT1 and OFDT2 were selected for stability studies.
The optimized fast dissolving tablets were packed in wide mouth air tight glass
container. Stability studies were carried out according to ICH and WHO guidelines as shown
in Table (6.17).
Table 6.17 Conditions as Per ICH Protocol
Time (Month) Conditions
0
250 C ± 20 C and 60 ± 5% RH 400 C ± 20 C and 75 ± 5% RH 3
6
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 187
6.6.2 Physical and chemical stability
The tablets are withdrawn after end of period and analysed for physical
characterization and drug content. The drug content data obtained was fitted in to first
order equation to determine the kinetics of degradation. Accelerated stability data were
plotted according to Arrhenius equation to determine the shelf life at 250 C.[178-180]
K= Ae-Ea/RT
T10% = 0.104/ K
Where, K is specific reaction constant; A is Arrhenius factor; T is absolute temperature; R is
Gas constant; Ea is energy of activation.
6.6.3 Comparison of dissolution profile
In recent years, FDA has placed more emphasis on a dissolution profile comparison
in the area of post-approval changes biowaivers. A dissolution profile comparison between
pre-change and post-change product or with different strength, helps assure similarity in
product performance and signal bioequivalence.
Among several methods investigated for dissolution profile comparison, f2 is the
simplest one.
f2= 50* log {*1 + (1/n) ∑t=1n (Rt - Tt)2] -0.5 * 100}
Where Rt and Tt are the cumulative percentage drug dissolved at each of the selected n time
points of the reference (before storage) and test (after storage) product respectively. When
the two profile are identical, f2 = 100. An average difference of 10% at all measured time
point’s results in f2 value 50. FDA sets a standard of f2 value in between 50 to 100; indicate
similarity between two dissolution profiles. [181-183]
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 188
RESULT and DISCUSSION
6.7 Characterization of taste masked granules of ondansetron HCl
In vitro taste evaluation
In vitro taste evaluation of different ratios of taste masked drug polymer complex
(DPC) was determined in phosphate buffer (pH 6.8) and in 0.1 N HCl (pH 1.2). Results are
shown in Table 6.18.
Table 6.18 In-Vitro taste evaluation
Drug Polymer Ratio in DPC % Drug Dissolve in Phosphate Buffer
(pH 6.8)†
% Drug Content in 0.1 N HCl (pH 1.2)†
1:1 2.0±0.21 98.42±0.25
1:3 0.82±0.15 98.72±0.41
1:5 0.41±0.05 99.12±0.08
† Results are the mean of 3 observations ± SD
Percentage drug content of drug polymer complex in 0.1 N HCl (pH 1.2) was found to
be 98.42 to 99.16. The drug release in phosphate buffer (pH 6.8) was found least with drug
polymer complex ratio (1:5). It showed that appreciable amount of drug was not released as
the drug particles were coated by the polymer. Thus complete taste masking was achieved.
DPC (1:5) was selected as an optimized ratio for the development of formulation.
Thermal analysis
Figure (6.1- 6.4) represented DSC Thermogram of ondansetron HCl, Eudragit® EPO,
drug-polymer physical mixture and drug polymer complex.
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 189
Figure 6.1 DSC Thermogram of ondansetron HCl
Figure 6.2 DSC Thermogram of Eudragit® EPO
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 190
Figure 6.3 DSC Thermogram of physical mixture
Figure 6.4 DSC Thermogram of drug polymer complex
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 191
Thermal profile of pure product exhibited a single endothermic effect corresponding
to the melting of ondansetron HCl (T fus 186.4770 C, ∆H fus 107. 379 J/g) while amorphous
nature of polymer. The DSC curve of physical mixture showed progressive broadening and
lowering of drug melting temperature and concomitant reduction of its enthalpy. In DSC
curve of DPC total disappearance of drug melting temperature. These finding suggest the
formation of new solid phase with lower degree of crystallinity.
FT-IR spectroscopy
Figure (6.5- 6.8) represented FT-IR spectroscopy of ondansetron HCl, Eudragit® EPO,
drug-polymer physical mixture and drug polymer complex. Interpretation of FT-IR is shown
in Table 6.19.
Figure 6.5 FT-IR spectra of ondansetron HCl
45060075090010501200135015001650180019502100240027003000330036003900
1/cm
30
40
50
60
70
80
%T
34
94
.17
34
13
.15
33
77
.47
32
46
.31
27
23
.58
26
67
.64
25
48
.05
24
63
.18
23
61
.91
21
30
.45
19
20
.20
18
45
.94
16
39
.55
15
32
.50
14
80
.42
14
59
.20
14
02
.30
13
38
.64
12
81
.74
12
44
.13
12
02
.66
11
30
.32
10
85
.96
10
44
.49
10
16
.52
91
5.2
5
84
9.6
7
76
2.8
7
66
5.4
6
59
9.8
8
54
4.9
1
Ondansetron HCl
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 192
Figure 6.6 FT-IR spectra of Eudragit® EPO
Figure 6.7 FT-IR spectra of physical mixture
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 193
Figure 6.8 FT-IR spectra of DPC
The FTIR spectrum of drug and polymer showed no significant shift or reduction in
intensity of peaks of ondansetron HCl. However, the FT-IR spectrum of DPC was found to
exhibit some significant difference in the characteristic peaks of ondansetron HCl, revealing
modification of drug environment. As shown in Figure 6.5, a broad band of bonded –OH of
ondansetron HCl was observed from 3412 to 3245.31 cm-1. DPC showed the absence of
peak at 3412 to 3245.31 cm-1 suggest the formation of complexation of drug with polymer
[205].
Table 6.19 Interpretation of FT-IR spectra
Functional group Band width
OH stretching -
C=O stretching 1730.02 cm-1
C-C stretching 2952.15 cm-1
C=N stretching 1640.41 cm-1
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 194
X- Ray Diffraction
Figure (6.9- 6.12) represented the X- ray diffraction pattern of ondansetron HCl,
Eudragit® EPO, drug-polymer physical mixture and drug polymer complex.
Figure 6.9 X-ray diffractogram of ondansetron HCl
Figure 6.10 X-ray diffractogram of Eudragit® EPO
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 195
Figure 6.11 X-ray diffractogram of physical mixture
Figure 6.12 X-ray diffractogram DPC
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 196
The x-ray diffractogram of ondansetron HCl confirms its crystalline nature, as
evidenced from the number of sharp and intense peak, (Figure 6.9). The diffractogram of
polymer (Eudragit EPO) showed diffused peak, indicating the amorphous nature (Figure
6.10) while the diffraction pattern of drug polymer physical mixture showed simply the sum
of characteristic peaks of pure drug and the diffused peaks of polymer, indicating presence
of drug in crystalline state. However the diffraction pattern of DPC represents complete
disappearance of crystalline peaks of drug (Figure 6.12) especially those situated between
200 and 600 (2θ). These finding suggest the formation of new solid phase with a lower
degree of crystallinity due to complexation which coincides with the conclusion of
Fernandes and Veiga [206].
6.8 Evaluation of FDT of ondansetron HCl prepared using different ratio of
mcc and lactose
6.8.1 Characterization of tablet
The preliminary trial batches were prepared using the formula given in Table 6.1 by
direct compression technique in order to study the effect of superdisintegrants and diluents
on the disintegration time and hardness. Results of the different batches showed a wide
variation in the disintegration time (22- 51 seconds) and hardness (3.4- 4.7 kg/cm2). On the
basis of these results, dependent and independent variable were selected and to
systematically study, different factorial batches (OH1 to OH12) were prepared and
evaluated.
Formulations OH1 to OH12 were characterized for different parameters as shown in
Table (6.20)
Friability of all the formulation was below 1% indicates that the tablets had good
mechanical resistance. Good uniformity of drug content was observed in all the
formulations. The weight variation results revealed that average % deviation of 20 tablets of
each formulation was less than ±7.5%, which provide good uniformity in all formulations.
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 197
Table 6.20 Characterization of fast dissolving tablets
Parameters Thickness Weight Friability Drug Content Wetting
time
Formulations (mm) (mg) (%) (%) (Seconds)
OH1 3.8±0.12 250.5±1.13 0.28±0.17 99.0±1.21 20±1.29
OH2 3.9±0.73 249.8±1.71 0.35±0.40 99.38±1.14 21±1.42
OH3 3.9±0.21 251.0±1.62 0.41±0.59 98.57±1.11 28±1.20
OH4 3.9±0.31 248.5±1.20 0.35±0.49 97.51±1.33 25±1.38
OH5 3.9±0.12 250.8±1.21 0.34±0.27 99.29±1.22 28±1.05
OH6 3.8±0.51 249.±1.32 0.42±0.38 96.92±1.41 21±1.29
OH7 3.9±0.26 250±1.28 0.31±0.47 98.49±1.71 20±1.14
OH8 3.9±0.50 251.0±1.11 0.28±0.24 97.54±1.29 15±1.44
OH9 3.9±0.30 250.0±1.24 0.31±0.40 98.29±1.31 22±1.04
OH10 3.8±0.21 249.5±1.17 0.28±0.62 99.74±1.30 18±1.29
OH11 3.8±0.20 250.0±1.07 0.36±0.55 100.5±1.42 20±1.19
OH12 3.9±0.21 250±1.28 0.29±0.63 98.5±1.19 18±1.28
Data are expressed as mean S.D. (n = 3)
Statistical design
A statistical model incorporating interactive and polynomial terms was used to
evaluate the responses.
Y= b0 + b1 X1+ b2 X2+ b12 X1 X2 + b12 X1
2 + b22 X2
2 + b12b2 X1
2 X2
Y is the measured response associated with each factor-level combination, b0 is the
arithmetic mean response of the total 12 runs; X1 and X2 are the factors studied, bi is the
regression coefficient for factor Xi computed from the observed response Y. The main
effects (X1 and X2) represent the average result of changing one factor at a time from its low
to high value. The interaction terms (X1X2) show how the response changes when two
factors are simultaneously changed. The polynomial terms (X12 and X2
2) are included to
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 198
investigate nonlinearity. Two conclusions could be drawn from the equation: (1) a
coefficient with a negative sign increases the response when the factor level is decreased
from a higher level to a lower level, and (2) the factor with a higher absolute value of the
coefficient and a lower significance value P” has a major effect on the response variables.
The dependent variables, disintegration time and hardness showed a wide variation
(Table 6.21). The data clearly indicates that the response variables are strongly dependent
on the selected independent variables. The high values of the correlation coefficient for
disintegration time and the hardness indicate a close fit.
Table 6.21 Results of each experimental run in full factorial design
Batch Response
Disintegration time (Y1) Hardness (Y2)
OH1 30±0.98 4.5±0.29
OH2 30±0.52 4.1±0.17
OH3 34±0.49 3.9±0.44
OH4 30±0.73 4.1±0.98
OH5 35±0.31 4.2±1.0
OH6 30±0.78 3.8±0.29
OH7 30±0.71 4.2±0.37
OH8 22±0.82 4.7±0.59
OH9 32±0.39 4.2±0.71
OH10 26±0.63 4.6±0.33
OH11 29±0.57 4.1±0.20
OH12 26±0.43 4.4±0.51
Data are expressed as mean S.D. (n = 3)
The fitted equations (full and reduced) relating the responses to the transformed
factor are shown in Table 6.24. Analysis of variance (ANOVA) was carried out to identify the
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 199
insignificant factors, which were then removed from the full model to generate the reduced
model. Results of ANOVA is represented in Table (6.22- 6.23).
Table 6.22 ANOVA for response surface reduced cubic model for disintegration time
Response model
Sum of square
Df Mean square
F value P value R2 Adeq.
Precision
DT 131.50 5 26.30 21.04 <0.0001 0.9460 15.811
Table 6.23 ANOVA for response surface reduced quadratic model
Response model
Sum of square
Df Mean square
F value P value R2 Adeq.
Precision
Hardness 0.76 3 0.25 45.14 <0.0001 0.9442 20.785
The Model F-value of 21.04 and 45.14 for didintegration time and hardness implies
the model is significant. There is only a 0.01% chance that a "Model F-Value" this large
could occur due to noise. Value of prob>F less than 0.0500 indicate that model term are
significant. Values greater than 0.1000 indicate the model term are not significant. "Adeq
Precision" measures the signal to noise ratio. A ratio greater than 4 is desirable, ratio of
15.811 and 20.785 indicates an adequate signal. This model can be used to navigate the
design space.
Table 6.24 Summary of result of regression analysis
Model* (DT)
b0 b1 b2 b12 b12 b2
2 b12b2
FM 30 -0.30 -4.50 -2.5 -1 - 3
RM 29.79 -4.33 -4.50 - - - -
Model* (Hardness)
b0 b1 b2 b12 b12 b2
2 b12b2
RM 4.17 0.32 0.13 - - 0.13 -
*FM indicate full model; RM indicate reduced model
For disintegration time, the coefficients of X1 and X2 that is, b1 and b2 respetively,
bear a negative sign, thus on increasing the concentration of MCC in MCC-Lactose
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 200
combination and conentration of Ac-Di-Sol, a decrease in disintegration time is observed.
For hardness, the coefficients of X1 and X2 that is, b1 and b2 respetively, bear a positive sign
thus on increasing the concentration of MCC in MCC-Lactose combination and conentration
of Ac-Di-Sol, a increase in hardness is observed.
Validation of statistical model
To validate the statistical model checkpoint batches, CP1 and CP2 were prepared
according to the formula. Comparison of predicted values and experimental values for check
point batches are shown in Table 6.25. From the response surface plot (Figure 6.13- 6.14)
and the calculations from the statistical equation obtained by regression, the results
revealed the close match of the experimental results. Thus, we can conclude that the
statistical model is mathematically valid. Overlay plot for hardness and DT is shown in Figure
6.15.
Table 6.25 Comparison of predicted values and experimental values for check point batches
Formulation code
Predicted Values
(DT)
Experimental Values (DT)
Residual Predicted
Values (Hardness)
Experimental Values
(Hardness) Residual
CP1 X1= +0.5
X2= 1 22.64 21±1.02 1.6 4.59 4.3±0.98 0.29
CP2 X1= +1
X2= +0.5 23.74 22±1.14 1.74 4.58 4.4±1.01 0.18
The best batch was selected after considering the requirements of an FDT. To full fill
these requirements, disintegration time and hardness was targeted to 25 s and 4.5 kg/cm2
respectively. The batches dissolution rates were also considered and batches with higher
dissolution rates were given priority. Different constraints were applied; responses were
predicted at 95% CI and they are found in range, which showed the robustness of the
statistical model (Table 6.26). Further, solution with desirability 1 was selected, as shown in
(Table 6.27).
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 201
Table 6.26 Predicted response at 95% confidence (n=1)
Response Prediction Std Dev SE (n=1) 95% PI low 95% PI high
DT 25 1.11803 1.25177 21.937 28.0629
Hardness 4.5 0.075 0.08386 4.3066 4.6934
Table 6.27 Predicted desirability
Number MCC Ratio Ac-Di-Sol DT Hardness Desirability
1 66.00 4.90 25 4.5 1.000
Figure 6.13 Response surface plot for disintegration time
Design-Expert® SoftwareFactor Coding: ActualDT
Design points above predicted valueDesign points below predicted value35
22
X1 = A: MCC RATIOX2 = B: Ac-Di-Sol
-1.00
-0.50
0.00
0.50
1.00
-1.00
-0.50
0.00
0.50
1.00
22
24
26
28
30
32
34
36
D
T
A: MCC RATIO B: Ac-Di-Sol
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 202
Figure 6.14 Response surface plot for hardness
Figure 6.15 Overlay plot for disintegration time and hardness
Design-Expert® SoftwareFactor Coding: ActualOverlay Plot
DTHardness
Design Points
X1 = A: MCC RATIOX2 = B: Ac-Di-Sol
-1.00 -0.50 0.00 0.50 1.00
-1.00
-0.50
0.00
0.50
1.00Overlay Plot
A: MCC RATIO
B: A
c-
Di-
So
l
DT: 25.000
Hardness: 4.500
4
DT: 25.000Hardness: 4.500X1 0.79X2 0.44
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 203
6.8.2 Characterization of optimized batch (OFDT1)
To determine the suitability of the powder blend for tablet compression, optimized
FDT (OFDT 1) was characterized for various flow properties as shown in Table (6.28).
Table 6.28 Physical properties of optimized tablet blend
Sr no. Formulation
Code
Bulk density (mg/ml)
Tapped Density (mg/ml)
Hausner’s Ratio
Carr’s Index (%)
Angle of Repose
(°θ)
1 OFDT 1 0.49±0.29 0.65±0.37 1.32±0.59 24.61±1.05 25.38±0.28
Data are expressed as mean S.D. (n = 3)
The tablet blend showed good flow ability (angle of repose < 300).Further optimized
FDT (OFDT 1) was characterized for different parameters as shown in Table (6.29).
Table 6.29 Characterization of optimized tablet (OFDT 1)
Parameters Thickness Diameter Weight Friability Drug
Content Wetting
time
Formulations (mm) (mm) (mg) (%) (%) (Seconds)
OFDT 1 3.9±058 9.0±0.38 250±1.49 0.29±1.58 99.98±1.78 15±0.88
Data are expressed as mean S.D. (n = 3)
Friability of all the formulation was below 1% indicates that the tablets had good
mechanical resistance. Good uniformity of drug content was observed in all the
formulations. The weight variation results revealed that average % deviation of 20 tablets of
each formulation was less than ±7.5 %, which provide good uniformity in all formulations.
Comparison of predicted responses and observed values for the disintegration time
and hardness (Table 6.30) were in close agreement, and the models were found to be valid.
Thus, full factorial design with two factors can be successfully used to optimize the
formulations.
Table 6.30 Comparison of predicted responses and observed values
Predicted Values
(Disintegration time)
Experimental Values
(Disintegration time)
Predicted Values
(Hardness)
Experimental Values
(Hardness)
25±0.4743 24±0.91 4.50±0.085 4.3±0.42
Data are expressed as mean S.D. (n = 3)
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 204
Figure 6.16 showed the in vitro drug release profile of all factorial batches and
optimized batch and it was found to be more than 95% in 4 minutes than compare to 90 %
in 10 minutes for marketed product (ONDEM MD8).
Figure 6.16 In vitro drug release profile of OFDT1 and formulation OH1- OH12.
6.9 Evaluation of fast dissolving tablets prepared using vacuum drying
technique
6.9.1 Characterization of tablets
The preliminary trial batches were prepared using the formula given in Table 6.12
using vacuum drying technique in order to study the effect of subliming material and
diluents on the disintegration time and hardness. Results of the different batches showed a
wide variation in the disintegration time (5- 91 seconds) and hardness (1- 4.9 kg/cm2). On
the basis of these results, dependent and independent variable were selected and to
systematically study, different factorial batches (OH1 to OH12) were prepared and
evaluated.
Formulations OV1 to OV12 were characterized for different parameters as shown in
Table (6.31).
0
20
40
60
80
100
120
0 2 4 6 8
%C
DR
Time (min.)
OFDT1OH1OH2OH3OH4OH5OH6OH7OH8OH9OH10OH11OH12
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 205
Table 6.31 Characterization of fast dissolving tablets
Parameters Thickness Weight Friability Drug Content Wetting
time
Formulations (mm) (mg) (%) (%) (Seconds)
OV1 3.9±0.18 249.5±1.25 0.32±0.54 101±1.42 25±1.48
OV2 3.9±0.57 250.2±1.47 0.64±0.47 100.5±1.17 14±1.59
OV3 3.8±0.29 251±1.59 0.67±0.53 99.59±1.31 13±1.28
OV4 3.9±0.48 248±1.25 0.24±0.44 98.79±1.19 24±1.39
OV5 3.8±0.72 250±1.39 0.58±0.27 99.08±1.28 19±1.25
OV6 3.8±0.59 249.5±1.28 1.2±0.39 97.82±1.49 4±1.29
OV7 3.8±0.76 250±1.45 0.56±0.58 97.75±1.77 14±1.44
OV8 3.9±0.58 250±1.28 1.8±0.37 99.50±1.25 5±1.57
OV9 3.8±0.39 250.5±1.39 1.6±0.48 99.29±1.33 5.5±1.04
OV10 3.9±0.71 249.8±1.40 0.62±0.47 99.10±1.28 12±1.43
OV11 3.9±0.28 250.5±1.25 0.72±0.53 99.62±1.48 7±1.41
OV12 3.8±0.29 251±1.32 0.24±0.63 97.2±1.73 22±1.29
Data are expressed as mean S.D. (n = 3)
Friability of all the formulation was below 1% indicates that the tablets had good
mechanical resistance except formulations OV6, OV8 and OV9 (% friability was more than
1). Uniformity of drug content was observed in all the formulations. The weight variation
results revealed that average % deviation of 20 tablets of each formulation was less than
±7.5%, which provide good uniformity in all formulations.
Statistical design
A statistical model incorporating interactive and polynomial terms was used to
evaluate the responses.
Y= b0 + b1 X1+ b2 X2+ b12 X1 X2 + b12 X1
2 + b22 X2
2 + b1 b22 X1 X2
2
Y is the measured response associated with each factor-level combination, b0 is the
arithmetic mean response of the total 12 runs; X1 and X2 are the factors studied, bi is the
regression coefficient for factor Xi computed from the observed response Y. The main
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 206
effects (X1 and X2) represent the average result of changing one factor at a time from its low
to high value. The interaction terms (X1X2) show how the response changes when two
factors are simultaneously changed. The polynomial terms (X12 and X2
2) are included to
investigate nonlinearity. Two conclusions could be drawn from the equation: (1) a
coefficient with a negative sign increases the response when the factor level is decreased
from a higher level to a lower level, and (2) the factor with a higher absolute value of the
coefficient and a lower significance value P” has a major effect on the response variables.
A statistical model incorporating interactive and polynomial terms was used to
evaluate the responses. The dependent variables, disintegration time and hardness showed
a wide variation (Table 6.32) 11 s to 35 s and 1.2 to 4.9 kg/cm2 respectively. The data clearly
indicates that the response variables are strongly dependent on the selected independent
variables. The high values of the correlation coefficient for disintegration time and the
hardness indicate a close fit.
The fitted equations (full and reduced) relating the responses to the transformed
factor are shown in Table 6.35. Analysis of variance (ANOVA) was carried out to identify the
insignificant factors, which were then removed from the full model to generate the reduced
model. Results of ANOVA are shown in Table (6.33- 6.34).
Table 6.32 Results of each experimental run in full factorial design
Batch Response
Disintegration time (Y1) Hardness (Y2)
OV1 35±0.89 4.2±1.51
OV2 23±0.57 3±1.32
OV3 23±0.73 3±1.57
OV4 33±0.59 4.6±1.28
OV5 28±0.96 3.3±1.34
OV6 8±0.62 1.5±1.52
OV7 23±0.71 3.1±1.24
OV8 11±0.67 1.3±1.29
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 207
OV9 12±0.91 1.2±1.47
OV10 22±0.85 3±1.19
OV11 15±0.89 2.7±1.28
OV12 32±0.90 4.9±1.30
Data are expressed as mean S.D. (n = 3)
Table 6.33 ANOVA for response surface reduced cubic model for disintegration time
Response model
Sum of square
Df Mean square
F value P value R2 Adeq.
Precision
DT 892.75 6 148.79 343.37 <0.0001 0.9976 52.708
The Model F-value of 343.37 implies the model is significant. There is only
a 0.01% chance that a "Model F-Value" this large could occur due to noise. "Adeq Precision"
measures the signal to noise ratio. A ratio greater than 4 is desirable. The ratio of
52.708 indicates an adequate signal. This model can be used to navigate the design space.
Table 6.34 ANOVA for response surface reduced quadratic model for hardness
Response model
Sum of square
df Mean square F value P value R2 Adeq.
precision
Hardness 16.16 4 4.04 1885.53 <0.0001 0.9991 126.057
The Model F-value of 1885.53 implies the model is significant. There is only a 0.01%
chance that a "Model F-Value" this large could occur due to noise.Values of "Prob > F" less
than 0.0500 indicate model terms are significant. "Adeq Precision" measures the signal to
noise ratio. A ratio greater than 4 is desirable. The ratio of 126.057 indicates an adequate
signal. This model can be used to navigate the design space.
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 208
Table 6.35 Summary of result of regression analysis
Model* (DT)
b0 b1 b2 b12 b12 b2
2 b1 b22
FM 22.58 -6.50 -11.50 -0.25 -0.75 -0.25 -8.25
RM 22.58 -6.50 -11.50 - - - -8.25
Model* (Hardness)
b0 b1 b2 b12 b12 b2
2 b1 b22
RM 3.02 0.27 -1.62 -0.10 - -0.067 -
For disintegration time, the coefficients of X1 and X2 that is, b1 and b2 respetively,
bear a negative sign, thus on increasing the concentration of mannitol and conentration of
camphor, a decrease in disintegration time is observed. For hardness, the coefficients of X1
and X2 that is b1 and b2 respetively, bears a positive sign and negative sign respectively, thus
on increasing the concentration of mannitol an increase in hardness andon increasing the
conentration of camphor, decrease in hardness is observed.
Validation of statistical model
To validate the statistical model checkpoint batches, CP1 and CP2 were prepared
according to the formula. Comparison of predicted values and experimental values for check
point batches are shown in Table 6.36. From the response surface plot (Figure 6.17- 6.18)
and the calculations from the statistical equation obtained by regression, the results
revealed the close match of the experimental results. Thus, we can conclude that the
statistical model is mathematically valid. Overlay plot for disintegration time and hardness
are shown in Figure 6.19.
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 209
Table 6.36 Comparison of predicted values and experimental values for check point batches
Formulation code
Predicted Values
(DT)
Experimental Values (DT)
Residual Predicted
Values (Hardness)
Experimental Values
(Hardness) Residual
CP1 X1= +1
X2= +0.75 15.81 17±1.24 1.1 1.96 2±0.89 0.04
CP2 X1= +0.75
X2= +1 9.76 11±1.17 1.24 1.4 1.6±0.95 0.02
Data are expressed as mean S.D. (n = 3)
The best batch was selected after considering the requirements of an FDT. To full fill
these requirements; concentration of mannitol was set 38% and concentration of camphor
13%. The batches dissolution rates were also considered and batches with higher dissolution
rates were given priority. Different constraints were applied; responses were predicted at
95% CI and they are found in range, which showed the robustness of the statistical model
(Table 6.37). Further, solution with desirability 1 was selected, as shown in Table (6.38).
Table 6.37 Predicted response at 95% confidence (n=1)
Response Prediction Std Dev SE (n=1) 95% PI low 95% PI high
Hardness 4.045 0.046291 0.0194 3.9296 4.1670
DT 29.954 0.658281 0.3320 28.0581 31.8506
Table 6.38 Predicted desirability
Number Mannitol Camphor Hardness DT Desirability
1 38 13 4.04 29.95 1.000 Selected
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 210
Figure 6.17 Response surface plot for disintegration time
Figure 6.18 Response surface plot for hardness
Design-Expert® SoftwareFactor Coding: ActualDT
Design points above predicted valueDesign points below predicted value35
8
X1 = A: MannitolX2 = B: Camphor
-1.00
-0.50
0.00
0.50
1.00
-1.00
-0.50
0.00
0.50
1.005
10
15
20
25
30
35
D
T
A: Mannitol
B: Camphor
Design-Expert® SoftwareFactor Coding: ActualHardness
Design points above predicted valueDesign points below predicted value4.9
1.2
X1 = A: MannitolX2 = B: Camphor
-1.00
-0.50
0.00
0.50
1.00
-1.00
-0.50
0.00
0.50
1.00
1
2
3
4
5
H
ard
ne
ss
A: Mannitol B: Camphor
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 211
Figure 6.19 Overlay plot for DT
6.9.2 Characterization of optimized batch (OFDT2)
To determine the suitability of the powder blend for tablet compression, optimized
FDT (OFDT 2) was characterized for various flow properties as shown in Table (6.39).
Table 6.39 Physical properties of optimized tablet blend
Sr no. Formulation
Code
Bulk density (mg/ml)
Tapped Density (mg/ml)
Hausner’s Ratio
Carr’s Index
(%)
Angle of Repose
(°θ)
1 OFDT 2 0.48±0.29 0.68±0.58 1.41±0.58 29.41±1.45 29.0±0.54
Data are expressed as mean S.D. (n = 3)
The tablet blend showed good flow ability (angle of repose < 300). Further optimized FDT
(OFDT 1) was characterized for different parameters as shown in Table (6.40).
Table 6.40 Characterization of optimized tablet (OFDT 2)
Parameters Thickness Diameter Weight Friability Drug
Content Wetting
time
Formulations (mm) (mm) (mg) (%) (%) (Seconds)
OFDT 2 3.9±0.72 9.0±0.24 250±1.38 0.36±0.89 99.57±1.18 23±0.68
Data are expressed as mean S.D. (n = 3)
Design-Expert® SoftwareFactor Coding: ActualOverlay Plot
DTHardness
Design Points
X1 = A: MannitolX2 = B: Camphor
-1.00 -0.50 0.00 0.50 1.00
-1.00
-0.50
0.00
0.50
1.00Overlay Plot
A: Mannitol
B: C
am
ph
or
DT: 32.000
DT: 32.000
Hardness: 4.000
4
DT: 29.954Hardness: 4.048X1 -0.20X2 -0.70
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 212
Friability of all the formulation was below 1% indicates that the tablets had good
mechanical resistance. Good uniformity of drug content was observed in all the
formulations. The weight variation results revealed that average % deviation of 20 tablets of
each formulation was less than ±7.5%, which provide good uniformity in all formulations.
Figure 6.20 showed a micrograph of the cross section of a high porosity fast
dissolving tablet. It was found that many porous cavities in the tablet were formed due to
the sublimation of camphor.
Figure 6.20 SEM micrograph of the cross sectional view of optimized tablet
after sublimation
Comparison of predicted responses and observed values for the disintegration time
and hardness (Table 6.41) were in close agreement, and the models were found to be valid.
Thus, full factorial design with two factors can be successfully used to optimize the
formulations.
Table 6.41 Comparison of predicted vs observed response
Predicted Values
(Disintegration time)
Experimental Values (Disintegration
time)
Predicted Values
(Hardness)
Experimental Values
(Hardness)
29.944±0.65 28±0.81 4.04±0.046 4.0±1.025
Data are expressed as mean S.D. (n = 3)
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 213
Figure 6.21 showed the in vitro drug release profile of all factorial batches and
optimized batch and it was found to be more than 95% in 4 minutes than compare to 90 %
in 10 minutes for marketed product (ONDEM MD8).
Figure 6.21 In vitro drug release profile of all factorial batches and optimized batch
6.10 Comparison of optimized formulation with marketed products
Table 6.42 represented the comparison of optimized formulation with market
product.
Table 6.42 Comparison of optimized formulations with market products
Formulation Hardness (kg/cm2)
Disintegration time (Sec) Friability
(%)
ONDEM MD 8 2± 1.0 30.00 ± 1.4 0.74 ± 0.5
ZOFER- MD 2.6 ± 1.7 50.21 ± 0.7 0.67 ± 1.0
ONDENZ DT 2.5 ± 1.5 45.03 ± 0.5 0.61 ± 1.1
OFDT1 4.4 ± 0.4 24.0 ± 0.9 0.29 ± 1.02
OFDT2 4.0 ± 1.0 28.0 ± 0 .81 0.36 ± 0.89
Data are expressed as mean S.D. (n = 3)
-20
0
20
40
60
80
100
120
0 2 4 6 8
% C
DR
Time (min.)
OFDT 2
OV1
OV2
OV3
OV4
OV5
OV6
OV7
OV8
OV9
OV10
OV11
OV12
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 214
0
20
40
60
80
100
120
0 2 4 6 8 10 12
% C
DR
Time (sec.)
OFDT1
OFDT2
ONDEM MD 8
Optimized formulations OFDT1 and OFDT2 were compared with various marketed
product of ondansetron HCl. Result showed that both the optimized formulations were
superior in terms of hardness, disintegration time and friability. Figure 6.22 represented the
In vitro dissolution of OFDT1 and OFDT2 with market product (ONDEM MD) in 0.1 N HCl.
Result showed that In vitro drug release from both the optimized formulations were found
to be more than 95% in 4 minutes than compare to marketed product 90 % in 10 minutes.
Further optimized formulation OFDT1 prepared using MCC: lactose combination as diluent
was found to be optimum in relation to disintegration time, hardness, friability and In-vitro
drug release. Hence, it was selected for further studies.
Figure 6.22 In-Vitro drug releases of OFDT1 and OFDT2 with marketed formulation in
0.1 N HCl
6.11 Pharmacokinetic study of ondansetron HCl fast dissolving tablet
A summary of pharmacokinetic parameter obtained after administration of
reference and test to rats shown in Table 6.43. Average ondansetron plasma concentration–
time profiles after test and reference products administration is shown in Figure 6.23.
Maximum plasma concentration after administration of reference and test was found to be
31.05 ng/ml and 32.5 ng/ml in 120 min and 60 min, respectively. The 90 % confidence
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 215
interval for AUC0-t (ng. h/mL), AUC0-∞ (ng. h/mL) and Cmax(ng/mL) for reference and test are
within 85-125% interval proposed by most regulatory agencies (FDA, EMEA, ANVISA). It was
concluded that the two formulations are bioequivalent in their rate and extent of
absorption and, thus, may be used interchangeably, without any prejudice of therapeutic
effect.
Table 6.43 Pharmacokinetic parameter for reference and test after oral administration
Parameters Reference Test (OFDT 1)
AUC0-t (ng. h/mL)* 250.67± 5.83 266.60± 4.092
AUC0-∞ (ng. h/mL)* 295.79± 3.014 309.2± 5.042
Cmax(ng/mL)* 31.05± 4.021 32.5 ± 1.62
Tmax(minute) 120 60
Ke 0.193 ± 1.012 0.225 ± 1.132
t1/2 (h) 3.59 ± 1.198 3.08±0.279
* p>0.05
Figure 6.23 Average ondansetron plasma concentration time profiles after test and
reference products administration
0
5
10
15
20
25
30
35
40
0 2 4 6 8 10
Co
nc.
of
dru
g in
pla
sma
(ng/
ml)
Time (h)
Reference
Test (OFDT 1)
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 216
0
100
200
300
400
500
600
700
800
Vehicle(Pre cond.) Lithium Sulphate Zofer-MD+ LiS Ondem-MD8+LiS OFDT 1+LiS
Tim
e Sp
ent
in W
hit
Bo
x
Treatment
Conditioning Post conditioning
6.12 Pharmacodynamic study for ondansetron HCl fast dissolving tablet
Conditioned placed aversion study was performed, in which behavior of animal was
studied after administration of drug. Although the pharmacological mechanism involved in
the conditioned place aversion is not known, a variety of drugs known to produce
gastrointestinal distress and vomiting produce a conditioned place aversion. The antiemetic
agent blocks this conditioned place aversion suggesting that this paradigm may serve as a
procedure to screen antiemetic activity in rodents [207].
It was found that after administration of potent emetic agent, lithium sulphate
animal behaved opposite to their normal physiology. Result shows (Figure 6.24) that animal
treated with fast dissolving tablets of ondansetron HCl spent more time in white box than
compare to market preparation (P<0.05). This shows the better performance of FDT than
compare to market formulations in nauseated condition.
Figure 6.24 Effect of Fast dissolving tablet of ondansetron HCl (Comp III) on conditioned place aversion induced by lithium sulphate (p<0.05)
The findings of pharmacokinetic and Pharmacodynamic study reveal the potential
role of fast dissolving tablets in reducing or management of nausea and vomiting.
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 217
6.13 Physical and chemical stability
Discoloration and liquefaction was not observed during storage period. No
significant change in hardness, disintegration time and drug content was observed as shown
in Table (6.44-6.49).
Table 6.44 Effect of storage condition on hardness of optimized tablets
Time period
(months)
At 400 C ± 20 C and 75 ± 5% RH* 250 C ± 20 C and 60 ± 5% RH**
OFDT1 OFDT2 OFDT1 OFDT2
0 4.4±0.68 4.0±0.19 4.4±0.68 4.0±0.19
3 4.2±0.79 3.9±0.25 4.3±0.49 3.9±0.54
6 4.1±0.58 3.8±0.42 4.2±0.44 3.8±0.71
Data are expressed as mean S.D. (n = 3)
Table 6.45 Results of unpaired t-test for hardness of different optimized tablets
P value (t- test) P value summary
OFDT1* OFDT2* OFDT1** OFDT2**
- - - - -
0.6468 0.7939 0.7988 0.7928 ns
0.4637 0.6025 0.2000 0.2000 ns
ns= not significant
Table 6.46 Effect of storage condition on disintegration time of optimized tablets
Time period
(months)
At 400 C ± 20 C and 75 ± 5% RH* 250 C ± 20 C and 60 ± 5% RH**
OFDT1 OFDT2 OFDT1 OFDT2
0 24.00±0.51 31.0±0.47 24.00±0.51 31.0±0.47
3 24.5±0.22 31.4±0.28 24.5±0.43 31.4±0.40
6 24.2±0.38 31.3±0.39 24.7±0.61 31.1±0.47
Data are expressed as mean S.D. (n = 3)
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 218
Table 6.47 Results of unpaired t-test for disintegration time of different optimized tablets
P value (t- test) P value summary
OFDT1* OFDT2* OFDT1** OFDT2**
- - - - -
0.2487 0.3468 0.2491 0.3456 ns
0.6278 0.5352 0.2020 0.8297 ns
ns= not significant
Table 6.48 Effect of storage condition on drug content of optimized tablets
Time period
(months)
At 400 C ± 20 C and 75 ± 5% RH* 250 C ± 20 C and 60 ± 5% RH**
OFDT1 OFDT2 OFDT1 OFDT2
0 99.98±0.66 99.78±0.52 99.98±0.66 99.78±0.52
3 99.94±0.51 98.82±0.41 99.43±0.67 98.72±0.97
6 99.00±0.89 98.68±0.71 99.12±0.23 98.35±0.91
Data are expressed as mean S.D. (n = 3)
Table 6.49 Results of unpaired t-test for drug content of different optimized tablets
P value (t- test) P value summary
OFDT1* OFDT2* OFDT1** OFDT2**
- - - - -
0.2566 0.1460 0.2765 0.2014 ns
0.0817 0.1080 0.1926 0.1084 ns
ns= not significant
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 219
1.98
1.985
1.99
1.995
2
2.005
0 30 60 90
Log
% d
rug
rem
ain
ed
Time (Days)
OFDT1 OFDT2
From the result shown in Table (6.44-6.49), it was concluded that formulations were
stable and no significant change in the percentage drug content, hardness and
disintegration time was to be observed. The drug content of the optimized formulations
were analysed for determination of shelf life of the formulations. [199]
Figure 6.25 showed the degradation kinetics of drug content of ondansetron HCl.
The shelf lives of optimized formulations are shown in Table 6.50, and it was found to be
more than 2 years.
Figure 6.25 Degradation kinetics of drug content of ondansetron HCl FDT
Table 6.50 Shelf life of optimized tablets
Formulation K T10% (Years)
OFDT 1 -0.000096 2.97
OFDT 2 -0.000093 3.06
K is degradation coefficient and (-) sign shows degradation
6.14 Comparison of drug release
Effect of storage on drug release for optimized formulations is shown in Figure (6.26-
6.27). No significant change in drug release was found.
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 220
Figure 6.26 Drug release form optimized formulation (OFDT1) before and after storage
Figure 6.27 Drug release form optimized formulation (OFDT2) before and after storage
0
20
40
60
80
100
120
0 2 4 6 8
Cu
mu
lati
ve %
dru
g re
leas
e
Time (min.)
Initial time
After 3 months
After 6 months
0
20
40
60
80
100
120
0 2 4 6 8
Cu
mu
lati
ve %
dru
g re
leas
e
Time (min.)
Initial time
After 3 months
After 6 months
Bhatt S.O. FDT of ondansetron HCl
K. B. I. P. E. R. Kadi Sarva Vishwavidyalaya Page 221
The dissolution similarity (f2) was also calculated to compare before and after
storage dissolution profile (Table 6.51). The f2 value was found to be more than 50,
indicating a close similarity between both the dissolution profiles.
Table 6.51 f2 value for optimized formulations
Formulations OFDT1 OFDT2
Time After 3
months
After 6
months
After 3
months
After 6
months
f2 89 80 88 84