film coating of tablets

Views:
 
     
 

Presentation Description

No description available.

Comments

By: moustafaatchy (58 month(s) ago)

Would you please send me the presentation .. I need it urgently moustafaatchy@gmail.com

By: maramfahim (59 month(s) ago)

please i need it badly,please send the PPT at my e-mail maram_mohamed_fahim@yahoo.com

By: yuritori9 (66 month(s) ago)

please help send me pee892004@yahoo.com.au

Presentation Transcript

PowerPoint Presentation:

Mechanism, factors, materials, defects in Film coating of tablets Presented by S.L. Priyanka ratnala m pharmacy 1 st year

PowerPoint Presentation:

1 Overview: 2 3 4 Mechanism of film formation Coating process and methods factors materials 5 defects

PowerPoint Presentation:

Film coating is applied for following reasons : Film coating is performed as two types: Aqueous film coating. Solvent – water Non aqueous film coating. Solvent - organic

PowerPoint Presentation:

Definition: Application of thin polymer based coatings to tablet/granules by a spray atomization technique. Thickness of such coating is usually between 20-100µm .

PowerPoint Presentation:

Film formation from polymeric solutions : Film formation from aqueous polymer dispersions:

PowerPoint Presentation:

Water evaporation Polymer deformation Aqueous dispersion Close packed spheres Continuous polymer film

PowerPoint Presentation:

Film coating is a discontinuous process??? Since each tablet receives only a small fraction of total coating when it passes through the spray zone, so the film coatings are built up as a series of layers one upon the another . Hence the surface of tablet is heterogeneous. Scanning electron micrograph of tablet surface showing heterogeneous nature.

PowerPoint Presentation:

Coating process: Application of coating composition to a moving bed of tablets with the concurrent use of heated air to facilitate evaporation of solvent . Methods of film coating:

PowerPoint Presentation:

FACTOR HAS INFLUENCE ON 1. Tablet core Ingredients Wetting by coating liquid. b) Porosity Adhesion of dry film. 2 . Coating liquid a) Viscosity b) Surface tension Spreading and coalescence of coating liquid on surface of tablet. 3 . Drying process a) Drying rate Viscosity of coating liquid. 4 . Airflow Temperature Humidity Rate at which solvent can be removed from coating liquid. 5. Nozzle design Pan speed Baffles Fineness of atomization of coating liquid. Uniformity of mixing. Factors affecting the quality of film coating :

PowerPoint Presentation:

Materials used in film coating: An ideal film coating material should have: Solubility in the solvent(pH dependent solubility, free water solubility). Stable in the presence of heat, light, moisture. Nontoxic. Compatible with the common coating solution ingredients .

PowerPoint Presentation:

Film Formers Example Non Enteric Materials Enteric Materials Hydroxy Propyl Methyl Cellulose Methyl Hydroxy Ethyl Cellulose Ethyl Cellulose Hydroxy Propyl Cellulose Povidone, Polyethylene glycol Sodium Carboxy Methyl Cellulose Acrylate Polymers – Eudragit E Cellulose Acetate Phthalate Acrylate Polymers- Eudragit L,S Hydroxy Propyl Methyl Cellulose Pthallate Polyvinyl Acetate Pthallate

PowerPoint Presentation:

Solvents Example Alcohols Esters Ketones Chlorinated hydrocarbons Water Methanol, Ethanol, Isopropanol Ethyl Acetate, Ethyl Lactate Acetone Methylene chloride Plasticizers Example Polyols Organic esters Oils/ glycerides Glycerol Poly ethylene glycol 200 – 6000 grades Triacetin, Diethyl pthallate Di butyl pthallate Castor oil, Fractionated coconut oil

PowerPoint Presentation:

Surfactants Example Polysorbates Sorbitan esters Tweens spans Colorants Example Inorganic Natural coloring material F D & C Lakes and dyes Iron oxide Anthocyanin, Caramel Carminic acid, Turmeric, Carotenoids Chlorophyll

PowerPoint Presentation:

Opaquant extenders Example Silicates Carbonates Sulfates Oxides Hydroxides Titanium dioxide, Talc Aluminium Silicate Magnesium Carbonate Calcium sulphate Magnesium Oxide Magnesium Hydroxide Miscellaneous Antioxidants, Flavors, Antimicrobials, Antiadherants(talc)

PowerPoint Presentation:

Film formers 1) Non enteric materials 2) Enteric materials Non enteric materials: Hydroxy propyl methyl cellulose: Its widespread acceptance include: Solubility characteristics in GI fluid. Non interference with tablet disintegration. Flexibility, absence of taste, odor. Stability in presence of heat. Ethyl cellulose: Insoluble in water & GI fluid. Hence used along with water soluble additives. SURELEASE is aqueous polymeric dispersion of ethyl cellulose - used for sustained release film coating. Hydroxy propyl cellulose: Used along with other polymers to improve film characteristics.

PowerPoint Presentation:

Povidone Available in different viscosity grades (k30, k60) ( tablet binder) It has good solubility & provide hard, clear, glossy films. Sodium CMC It is easily dispersible in water to form colloidal dispersion. but insoluble in most organic solvents, hence not preferred. Films prepared are brittle. Polyethylene glycol Available in low & high molecular weights. Films prepared with high molecular weight PEG are hard, smooth, tasteless. Combination of PEG with cellulose acetate phthalate produce films soluble in GI fluids. Acrylate polymers Marketed under trademark EUDRAGIT EUDRAGIT E : It is a cationic copolymer, freely soluble in GI fluid up to pH 5 & expandable permeable above pH 5. These Films are used for delayed action.

PowerPoint Presentation:

Enteric materials: Why Enteric coating is done??? To protect acid labile drugs from gastric fluid e.g. antibiotics To prevent gastric distress e.g. sodium salicylate To provide a delayed release component. Cellulose acetate phthalate: Dissolve only above pH 5. CAP films are brittle. AQUATERIC COATING (aqueous enteric coating) composed of polymer spheres of CAP. Acrylate polymers: EUDRAGIT L - soluble in intestinal fluid at pH 6. EUDRAGIT S- soluble in intestinal fluid at p H7.

PowerPoint Presentation:

Hydroxy propyl methyl cellulose phthalate Marketed as HPMCP 50, 55, 55 S. Soluble at lower pH (5-5.5) Result in higher bioavailability. Poly vinyl acetate phthalate Has pH dependent solubility. Solvents: To dissolve or disperse the polymer. Ideal characteristics of a solvent: Should have rapid drying rate. Non toxic. Aqueous solvent based coatings are much preferred than non aqueous organic solvent based coatings. Tensile strength Elastic modulus Film adhesion Effect of increasing polymer molecular weight on coating property increase increase decrease

PowerPoint Presentation:

Plasticizers: Make polymer soft & enhance flexibility. Modify physical & mechanical properties of film. Reduce glass transition temperature of amorphous polymer & impart flexibility. Recommended levels of plasticizer range: 1- 50% wt of film former. The quality of polymer film is modified by : 1) Internal plasticization chemical changes are made within the structure of polymer. 2) External plasticization by using additives- plasticizers. Tensile strength Elastic modulus Film adhesion Effect of increasing concentration of plasticizer on coating properties decreases decreases increases

PowerPoint Presentation:

Colorants: May be soluble in solvent system or suspended as insoluble powder. For light shade: 0.01% For dark shade: ≥ 2.0% E.g .. OPASPRAY: opaque color concentrate for film coating. Opaquant extenders: To increase film coverage. To mask color of tablet core. Tensile strength elastic modulus Effect of increasing concentration of pigment on coating properties Decreases Increases

PowerPoint Presentation:

PROBLEMS ENCOUNTERED DURING FILM COATING:

PowerPoint Presentation:

Picking: A piece of film may remain adhered to pan. Reason: localized over wetting. Remedy: Increase drying air temperature. Reduction in liquid application rate. Picking does not occur alone it must have another tablet to be stuck with which called sticking: Sticking is the defect that the broken film comes from picking tablet and sticks on the tablet surface.

PowerPoint Presentation:

TWINNING: Tablets with flat edges/faces may become permanently glued together. Mottled color: Migration of soluble dyes during drying. Remedy: use of lake dyes eliminate migration .

PowerPoint Presentation:

Orange peel effect: Inadequate spreading of coating solution before drying. Reason: Too rapid drying. High solution viscosity. Remedy: Thinning the solution with additional solvent . ROUGHNESS: Roughness of the film. Reason: when coating is applied by spray, some of the droplets dry before reaching the tablet bed. Remedy: moving the nozzle close to tablet bed . Roughness

PowerPoint Presentation:

Bridging: During drying film may shrink & pull away from the sharp corners of bisect, resulting in bridging of surface depression. So the monogram/ bisect is completely obscured. Remedy: increase or change plasticizer. FILLING: Filling is caused by applying too much solution, resulting in a thick film that fills and narrows the monogram or bisect. Remedy: Monitoring the fluid application rate.

PowerPoint Presentation:

EDGE WEAR: Reason: Tablet core having high friability values. Worn punches . CHIPPING: Reason: This is the result of high pan speed, a friable tablet core, or a coating solution that lacks a good plasticizer.

PowerPoint Presentation:

FILM CRACKING: Reason: If internal stresses in film exceed the tensile strength of film Remedy: Tensile strength is increased by using high molecular weight polymer. internal stress is decreased by adjusting plasticizer concentration. BLOOMING/DULL FILM: Coating becomes dull. Reason: Too high processing temperature & humidity. High concentration & low mol. Wt of plasticizer. Remedy: decrease plasticizer conc. & increase mol.wt of plasticizer.

PowerPoint Presentation:

Other problems encountered during film coating: Due to excessive moisture with in the tablet which prevented coating from adhering.

PowerPoint Presentation:

REFERENCES: The theory & practice of industrial pharmacy by Leon lachman, Herbert A. Lieberman. Tablet volume -3 www.google.com.

PowerPoint Presentation:

THANK YOU…

authorStream Live Help