Storage and Stability of Drugs (Students)

7/23/2019 Storage and Stability of Drugs (Students)

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Storage and Stability of Drugs

by

Tan Mui Ling



Storage and Stability of Drugs 2

Look-alike drug names

Ethambutol 1,000 mg was

prescribed for an HIV patient withtuberculosis.

However, the patient received onedose of the antiarrhythmic

Ethmozine (moricizine) 1,000 mgbefore the error was discovered.

ismp 6 Oct, 1999




Look-alike drug names & strengths

Similar names and strengths

contributed to a pharmacistmisreading an order for ZYVOX

(linezolid) 600 mg BID asZOVIRAX (acyclovir) 600 mg BID.




Look-alike drugs

A pharmacy technician was preparing two

doses of pamidronate 90 mg for IVinfusion. She reached into the product's storage

bin and picked up two vials, one of

pamidronate 90 mg and another ofetomidate 40 mg (2 mg/mL, 20 mL) thatlooked nearly identical. Both productswere distributed by Bedford Laboratories

and packaged in grey and white vials andcartons.




Look-alike drugs




Infection linked to multi-dose vial

Problem

An outbreak of Staphylococcus aureusinjections has been associated withmultiple-dose vials of lignocaineused during injections into joints.

Recommendation

Use prefilled lignocaine syringes orsingle-dose vials.ismp apr-jun 2003




Check your inhaler before use

After using his albuterol inhaler, an

asthmatic man began to coughuncontrollably. Instead of the medicine making it easier

for him to breathe, he felt like something

was stuck in his breathing passages. An x-ray at a clinic confirmed that there

was a coin in his windpipe – a dime thathad to be removed through a tubeinserted down his throat

The man later told the doctor that he keptthe inhaler in his pocket without the dust

cap on along with money and coins.




Check your inhaler before use

This allowed a dime to become lodged in

the opening of the inhaler and be inhaledalong with the medicine.

People who use inhalers should always

keep the dust cap in place between uses. They should check the mouthpiece before

use.

Even a little dust or lint can causeproblems if pushed into the windpipe orlungs when using the inhaler.

ismp sep/oct 2005




Prevent accidental vitamin

overdoses

How much time does a 2-year-old child

need to gobble up to 95 vitamin Ecapsules?

About 10 minutes, according to a recent

caller to a poison control centre. Shortly after that, the little boy

complained that his stomach hurt, and hevomited.

However, that was all that happened andhe was fine later.




Prevent accidental vitamin

overdoses

The bottle in this case did not have

a safety cap, and the boy easilyopened it.

Remember that all medications,including vitamins and herbalproducts, should be stored out of

reach of children, EVEN if thebottles have child-resistant caps




Storage– Guidelines for proper storage

of medicine

Keep out of the reach of ___________ Keep medicines in their ____________

containers.

Store away from ______ and direct ______ .

In planning and choosing accommodation

for storing drug formulations, it isimportant that a _____, adequatelyventilated, shady and _______ room ischosen.





of medicine

Do not store capsules or tablets in

the bathroom, near the kitchen sink,or in other _________ places.

Heat or ___________ may cause themedicine to break down.

Drugs are stored so that packed

medications received _____ are alsothe _______ to be issued, using first-in first-out rule.





of medicine

Store medications for external use separate

from those for _____________ use. Also do not leave the cotton plug in a

medicine container that has been _______,

since it may draw moisture into thecontainer.

Keep liquid medicines from __________ .

Do not store medicines in the _________unless directed to do so.





of medicine

Do not leave your medicines in an

automobile for _______ periods of time. Do not keep outdated medicine or

medicine that is no longer _________ .

Don’t keep tubes of ointments or creamsnext to your tube of ________. They feela lot alike when you grab quickly, but a

mistake could be serious.




Importance of proper storage

Medications last only as long as their

__________ conditions are favourable. Drugs can lose their potency long before

their expiration date if exposed to

_______ , heat, ________ or humidity. Most country’s Food and Drug

Administrations require pharmaceutical

manufacturers to provide _______ ____on all their products.





These dates range from 12 to ___ months

from the date they are manufactured. Expiration dates are basically _________.

Medications may __________ before the

expiration date if improperly ________or they may last well beyond theirexpiration date, as some studies have

shown.





Some drugs, like paediatric liquid

antibiotics, insulin and certaininjections will expire more ______than medications in other form,

such as tablets. For reconstituted injections, follow

the “discard dates” according to

package insert. They range fromdiscard ____________ to 30 days.




General advice on safe medication use

Store medications where children can’t

see or reach them, for example, in a _______ box or cabinet.

Turn on the _________ to take your

medications. Keep medications for people separate

from pets’ medications or household

chemicals. Mix-ups are common and canbe ______________.




Stability of medications

No pharmaceutical product is

________ indefinitely and certainlythe majority of products are stableonly for a _________ time.




Results of pharmaceutical product

instability

Loss of ________ drug (e.g.

aspirin) through hydrolyis.

Loss of __________ e.g.

evaporation of alcohol fromalcoholic mixtures, evaporation of ________ from aqueous mixtures.

Loss of _________ uniformity e.g.impaction of suspensions.




Results of pharmaceutical product

instability

Reduction in __________ e.g.

ageing of tablets resulting in achange in dissolution profile.

Loss of pharmaceutical _________

e.g. fading of coloured solutions andtablets.

Production of potentially ______materials e.g. breakdown productsfrom drug degradation.




Degradation of pharmaceutical

products

Classified as being due to:

chemical mechanisms

physical mechanisms

biological mechanisms




Chemical Degradation

(a) Solvolysis

Involves the _________ of the drugor excipients through reaction with

the solvents present in theformulations.

As water is the most common

solvent in pharmaceutical products,the degradation will be ________.





(b) Oxidation

Oxidation is an extremely common causeof ______ and _________ degradation.

Occurs in both water-soluble and oil-

soluble drugs as well as in _____ and ________ oils.

A substance is said to be ________if it

gains electronegative atoms or radicals orloses electropositive atoms or radicals.





(c) Photolysis

Degradation of drugs or excipientmolecules can be brought about by ____,either _______light or ___________.

Such reactions are termed photolysis andlight-sensitive drugs are known as ___________.

Photolytic reactions include the darkeningof morphine and codeine, the _______ oftartrazine dye.





(d) Polymerization

Involves the ___________ of two or moreidentical molecules to form a much largerand complex molecule.

Degradation of pharmaceutical productsby polymerisation is not very commonand such reactions may occur after theinitial degradation of the drug.

An example is production of a straw-coloured solution after the autoclaving of

________ injection.




Physical Degradation

(a) Polymorphism

Polymorphs are different _______forms of the same compound.

For example, theobroma oil usedin the preparation of suppositorieshas ___ polymorphs. The ß formhas a melting point at ______,while the α form has a meltingpoint of 30oC.




Physical Degradation(b) Vaporization

Many drugs and excipients may be _____from pharmaceutical products at ambienttemperatures through vaporisation.

These drugs and excipients possess a

sufficiently high vapour pressure thatthey are _______ at room temperature.

Examples of such drugs are glyceryltrinitrate (GTN), alcohols, camphor.

These drugs may be lost from the productbecause of loose-fitting _________ .




Physical Degradation

(c) Water loss

Evaporation of water from ________preparation will cause change ofconcentration of the drug with the

possibility of crystallization occurring ifthe solubility of the drug in the solvent isexceeded.

________ loss to the atmosphere can beprevented by storing the pharmaceuticalproduct in a well-closed container.




Physical Degradation(d) Absorption of water

Water will be ___________ from theatmosphere by some drugs andpharmaceutical products.

For example, some drugs aredeliquescent (calcium chloride andpotassium citrate) whereas others arehygroscopic (glycerol)

Effervescent powders and tablets willdeteriorate if __________ in a

_________ atmosphere.




Factors Influencing Degradation(a) Temperature

An increase in _____________ generallyincreases the ______ of reactions.

Thus the degradation of pharmaceutical

products is generally increased with an __________ in temperature.

One method of preventing or reducingdegradation is to store thepharmaceutical product at _______temperature e.g. Insulin injection arenormally stored between 2oC and 8oC.




Factors Influencing Degradation

(b) Solvent

Drugs may be placed in a variety of _________ in order to produce a

suitable dosage form. However, the different solvents

used may influence the _________

of the drugs.





The most commonly used solvent is

_______ and unfortunately manydrugs hydrolyse in water.

The hydrolysis rate can be catalysedby the presence of _________ oralkalis which supply hydrogen ions

or hydroxyl ions to the solution.





(c) Moisture (atmospheric)

________ or _____ can adversely affectthe stability of dry drug formulations,such as tablets and capsules.

For example, gelatin capsules becomesoft and swell in the presence ofmoisture.

The presence of _______ may encouragethe growth of micro-organisms.

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Storage and Stability of Drugs (Students)