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CHEE 440 1

Tablet CoatingTablet Coating

Why coat tablets?

Types of coatings

sugar coating

film coating press coating (compression coating)

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CHEE 440 2

Sugar CoatingSugar Coating

stages involved sealing of tablet core

subcoating

smoothing

colouring

polishing

printing

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CHEE 440 3

Film CoatingFilm Coating

involves spraying a solution ofpolymer + pigments +

plasticizers onto a rotated, mixed tablet bed

forms a thin, uniform film on tablet surface

materials

polymers

solvents

plasticizers

colorants

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CHEE 440 4

Film FormationFilm Formation

latex particles dispersed

in aqueous phase

formation of thin film with

water evaporation through film

continuous film

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CHEE 440 5

Coating ProcessCoating Process

coatingpans

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CHEE 440 6

Coating ProcessCoating Process

fluid beds

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CHEE 440 7

Important Processing ParametersImportant Processing Parameters

inlet and bed temperatures

relative humidity

atomization airpressure

liquid spray rate

droplet size

drying time

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CHEE 440 8

Coating ProblemsCoating Problems

picking/chipping

roughness

sticking

film cracking/peeling

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CHEE 440 9

Normal CoatingNormal Coating

Descri tiRec stit tilevel

Aver ewei t

iA lic ti examples

HPMC basedA eoussystem

11% to15% 2.5%

HPMC basedOr anicsolventsystem

5% 2.5%

HPMC basedA ueous/Or anicSolvent/

HydroAlcoholicsystem

A ueous 11%

Or anic Solvent5%

Hydro Alcoholic9%

2.5%

PVA basedA ueoussystem

20% to25% 2.5%

Amoxycillin, Azithromycin, Atenolol,Amlodipine, Amitriptyline, AmpicilinCiprofloxacin, Cephadroxil ,Cimitidine, Calcium Tablets, Citrizine

, Chloroquine Phosphate,Clarithromycin, Erythromycin,Ferrous Fumarate,Famotidine,Ferrous Sulphate, Ibuprofen,Indapamine, Losartan Potassium,Levamisole, Methyl-Dopa,Metronidazole+Tinidazole,Metronidazole, Methyl Coblamine,Mefenamic Acid, Metoprolol Tartrate,

Norfloxacin,Nifidipine,Norfloxacin+Tinidazole,Ofloxacin,Paracetamol, Quinine Sulphate,Roxythromycin, Secnidazole,Sildenafil Citrate, Trimetazidine,Tinidazole, Tinidazole-Doxycycline,Tinidazole+ Tetracycline, Verapamil

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CHEE 440 10

EntericEnteric--coatedcoated

coating resists dissolution or disruption in stomach

but not in intestines

used for drugs that are unstable, irritating to

stomach

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CHEE 440 11

Enteric CoatingEnteric Coating

DescriptionReconstitutionlevel

Averageweightgain

Application ** examples

Organic EntericCoating system,Cellulose Acetate

Phthalate based

5% 8%

Aqueous coatingsystem & Organicenteric coatingsystem. HydroxyPropyl Methyl

Cellulose Phthalate

based system.

Organic: 5%Aqueous: 10%

8%

Methacrylic acidcopolymer type "C"USP/NF basedsystem

Aqueous 20%

Hydro Alcoholic10%

Organic System10%

9%

Aspirin, Bisacodyl

Diclofenac Sodium

Doxylamine Succinate

Garlic Tablets,Omeprazol,

Pentaprazole,

Pentoxyfyline, Rabeprazol ,

Serrosipeptadise

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CHEE 440 12

Press CoatingPress Coating

use of compression to form coat around a pre-formed core

used mainly to separate chemically incompatiblematerials

also dual release patternspossible