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Presentation film coating

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presentation of film coating

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Presentation film coating

  1. 1. FILM COATING TECHNIQUES AND PROBLEMS. Submitted by:- Ajit kr. Jha M.Pharm (Pharmaceutics) Submitted To:-Dr. Majumdar D. K. Dept. of pharmaceutics School of pharmacy,
  2. 2. FILM COATING TECHNIQUES AND PROBLEMS
  3. 3. OVER VIEW : 1.INTRODUCTION 2.MECHNISM OF FILM FORMATION 3. COATING PROCESS AND METHOD 4. MATERIALS 5. DEFECTS
  4. 4. COATING: A coating is a covering that is applied to the surface of an object. It is the application of coating composition on to the moving bed of tablets with concurrent use of heated air to facilitate evaporation of the solvent.
  5. 5. PURPOSE OF COATING:- To mask unpleasant taste . To control site of dissolution. To protect components atmospheric degradation such as oxidation ,absorption or evolution of moisture ,light etc . To separate incompatible ingredient and prevent their interaction. To provide a controlled rate
  6. 6. INTRODUCTION:- • A film is a thin polymer –based coat applied to a solid dosage form such as a tablet granule or particle. • The thickness of such a coating is usually between ( 20 to 100 micrometer) • Each and every tablet is passed through a spray zone, where the adherent material is sprayed and allowed to dry before the next portion of coating and this process is repeated number of times.
  7. 7. REASONS :-
  8. 8. Enhancing flavor FILM COATING IS APPLIED FOLLOWING REASON:- Modifying drug release characteristics Improving Product stability Aqueous film coating :- [ solvent - water ] Non aqueous film coating :- [ solvent – organic] 1. FILM COATING IS PERFORMED AS TWO TYPES:-
  9. 9. FORMATION OF FILMS FROM AQUEOUS POLYMERIC DISPERSIONS This requires the coalescence of polymer particles into a continuous film. This process involves:  Rapid evaporation of water, causing the particles of dispersed polymer to be brought into close contact with one polymer.  Development of pressures (associated with capillary forces within the structure) that overcome repulsive forces between particles and cause deformation of the polymer particles.  Gradual coalescence of the polymer particles as a result of viscous flow and movement of polymer molecules across the interfaces between particles.  Aqueous polymeric must be processed at temperatures in excess of the glass-transition temperature of the polymer.
  10. 10. MECHANISM OF FILM FORMATION
  11. 11. SUB TYPES:- FILM COATING ARE SHOWES VARIOUES SUBTYPES:- • CONVENTIONAL FILM COATING. • MODIFIED RELEASE FILM COATING . • SUSTAINED RELEASE FILM COATING. • ENTERIC FILM COATING.
  12. 12. CONVENTIONAL FILM COATING:- It has been applied to improve product appearance ,improve stability and ease of ingestion without altering drug-release characteristics form the dosage form .conventional coating is the area where aqueous technology has gained the highest
  13. 13. MODIFIED RELEASE FILM COATING:- Film coating techniques can be effectively used either to sustain the release (extended release)0r delay the release (enteric coating) of drug.
  14. 14. SUSTAINED RELEASE FILM COATING : The film coating act a membrane that allows infusion of GI fluid and the outward diffusion of drug or the release process may amplified by a coating that slowly dissolves/ the subjected by enzymes. The most common application of sustained release coating is on micro particles that are subsequently encapsulated or tablet .
  15. 15. ENTERIC FILM COATING :- The drug delivery system to pass through the stomach intact and dissolve upon reaching the intestine.
  16. 16. COATING PROCESS Application of coating composition to a moving bed of tablets with the concurrent use of heated air of facilitate evaporation of solvent . Film-coating of tablets is a multivariate process, with many different factors, such as coating equipment, coating liquid, and process parameters which affect the pharmaceutical quality of the final product
  17. 17. Coating equipment Before few years different types of coating pans are used for coating like conventional coating pans, manesty accelacota, driam ( driacoater ), butterfly coater etc. Now a days the side-vented, perforated pan-coater is the most commonly used coating device of tablets. In equipment spray nozzle, number of spray nozzle, pan size, etc may also affect the quality of final product. Its air flow system through a perforated pan ensures rapid and continuous drying conditions. The low evaporation capacity of water requires
  18. 18. COATING LIQUID Coating liquid may affect the final quality of the tablets. Different film former have different chemical nature and different characteristic. Viscosity may affect the spreading of coating liquid across surface of substrate. Surface tension may affect in wetting of surface. % Solid content generally affect the tablet surface and coating efficiency.
  19. 19. CONVENTIONAL COATING PANS : It consists of a circular metal pan placed angularly on a stand rotated on its horizontal axis by motor . Heat is directed in the pan on the tablet bed surface and is exhausted by means of ducts .
  20. 20. PERFORATED PANS : This is an angular pan operating on a horizontal axis. Drying air is directed into the pan, through the tablet bed, and exhausted out the perforations in the periphery of the pan. Accela Cota
  21. 21. This is similar to Accela Cota, but only a portion of the pan periphery has perforations. Like the Accela Cota, continuous venting of the exhaust air from the pan is still attained. HI-COATER
  22. 22. DRIA COATER PAN
  23. 23. PROCESS PARAMETERS • Many quality aspects of the final coated product are greatly influenced by the combined effect of process parameter values used in aqueous film coating. • Coating process parameters affect the spreading, penetration and drying (i.e. evaporation of water) of the coating liquid on the tablet surface and, subsequently, the surface roughness and the residual moisture of the coated tablets.
  24. 24. SPRAYING AIR PRESSURE: • The spraying air pressure disperse the coating liquid into droplets and effects the droplet size distribution and droplet spreading and penetration on the tablet surface. • The formation of adequate and adhesive film coat, the atomized droplets have to spread completely over the surface of the tablet. • Increasing the spraying air pressure decreases the surface roughness of coated tablets and produces denser and thinner films. • If spraying air pressure is excessive the spray loss is great. The formed droplets are very fine and could spray dry before reaching the tablet bed, resulting in inadequate droplet spreading and coalescence. • Spraying air pressure is insufficient, the film thickness and thickness variation greater possibly due to change in film density and smaller spray loss.
  25. 25. FLOW RATE OF COATING SOLUTION • Successful aqueous coating process, the flow rate of the coating liquid is equal to the rate of water evaporation from the coated tablet surface. • Increasing the flow rate allows greater number of droplets to be spread on to the tablet bed per time and increases droplet size. • The flow rate is important parameter since it impacts the moisture content and the quality and uniformity of the film. • Low coating liquid flow rate causes incomplete coalescence of polymer due to insufficient wetting, which result in brittle films. • High coating liquid flow rate may result in over wetting of the tablet surface and subsequent problems such as picking and sticking.
  26. 26. PAN AIR TEMPERATURE • The pan air temperature effects drying efficiency of the coating pan and the uniformity of the coatings. • High inlet air temperature increases drying efficiency of aqueous film coating process and decreases in water penetration into the tablet coating. • Excessive air temperature increases premature drying of the spray during application and subsequently decreases the coating efficiency.
  27. 27. ROTATING SPEED OF THE PAN • Increasing rotating speed of the pan improves mixing of the tablets. • The pan speed effects the time the tablet spend on the spraying zone and subsequently, the homogenous distribution of the coating solution on the surface of each tablet throughout the batch. • Increasing the pan speed decreases thickness variation and improves the uniformity of the coating. • Too rapid rotating speed of the pan will cause the tablet to undergo excessive attrition and breakage.
  28. 28. FILM COATING METHODS :- 1.PAN POUR METHOD. 2.PAN SPRAY METHOD.
  29. 29. GENERAL PROCEDURE The aqueous coating liquid is commonly applied by pneumatic (air) spray systems where the pressure of the spraying air disperses the coating liquid as appropriately sized droplets  The coating of tablets in a coating pan involves spraying the coating compositions through one or more spray guns onto rotating bed of tablets.  Coating process consists of the continuous application of coating liquids to a small portion of the tablets in the pan.  The applied coating must dry before it touches the coating pan or receives its next application.  To attain a continuous coating operation, the rate of water evaporation from the coated tablets must equal the rate of water applied in the coating liquid.  The coating composition is also significant factor in establishing the tablet coating rate. Coating compositions that are quite tacky during the drying phase must be applied at a slower rate to avoid tablets sticking to pan surface or other tablets.
  30. 30. MATERIAL USE OF FILM COATING  A ideal film coating material should have:- Solubility in solvent (PH dependent solubility , free water solubility) Stable in the presence of heat light moisture . Non toxic. Compatible with the common coating solution ingredients.
  31. 31. Non enteric materials- Enteric materials- Example:-Hydroxyl propyl methyl cellulose, sod.corboxy cellulose, ethyl cellulose, acrylate polymer EudragitE, povidon, proply ethylene glycol. Example:- cellulose acetate phthalate,acrylate polymer,EudragitL,S ,Hydroxyl propyl methyl cellulose phthalate, FILM FORMER :-
  32. 32. Solvent Alcohol Ester Ketons Chlorinated hydrocarbons Water methanol,ethanol,isopropano l, Ethyl acetate ,ethyl Acetone Methylene choride
  33. 33. Plasticizers:- Polyols Organic esters Example:- Glycerol poly, ethylene glycol(200-600grades) Triacetin,diethyl phthalate, Dibutyl phthalate Castoe oil, fractionated coconut
  34. 34. EFFECTS OF PLASTICIZERS ON THE PROPERTIES OF FILM COATINGS PROPERTY Tensile strength Elastic modulus Film adhesion Solution viscosity Film permeability EFFECT OF INCREASING PLASTICIZER CONCENTRATION Decreased. Decreased. May be increased, but results often variable. Increased, and magnitude of effect dependent on molecular weight of plasticizer.
  35. 35. Surfactant :- Poly sorbets Sorbitan ester Colorants:- Inorganic Natural coloring material Example:- Tweens Spans Example:- FD&C, lakes & dyes,iron oxide Anthocyanin,caramel,Tur
  36. 36. EFFECTS OF PIGMENTS ON THE PROPERTIES OF FILM COATINGS P R O P E R T Y Tensile strength Elastic modulus Film adhesion Solution viscosity Film permeability EFFECT OF INCREASING PIGMENT CONCENTRATION Decreases Increases Little effect. Increases, but not substantially. Decreases, unless critical pigment volume concentration is exceeded.
  37. 37. Opaquant extenders:- Silicates Carbonates Sulfates Oxides Example:- Titanium dioxide,talc. Aluminium silicate Mg carbonate . Calcium sulphate. Mg oxides, hydroxides .
  38. 38. Miscellaneous :- Example:- Antioxidants flavours, Antiadherants, talc etc.
  39. 39. FILM FORMERS :- Non enteric materials: -HYDROXY PROPYL METHYL CELLULOSE:- It is wide spread 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 GI fluid. Hence used along with water soluble additives. It is aqueous polymeric dispersion ethyl
  40. 40. HYDROXY PROPYL CELLULOSE:- Used along with polymer to improve film characteristics . PROVIDON:- Available in different viscosity grades (K30,K60) It has good solubility & provide hard clear glossy films. SODIUM METHYL CELLULOSE:- It is easily dispersible in water to form colloidal dispersion in most organic solvent hence not preferred. Film prepared are brittle.
  41. 41. POLY ETHYLENE GLYCOL:-  Available in low & high molecular weights Film prepared with high mol .wt combination PEG with cellulose acetate phthalate produce films soluble in GI fluid.  Low mol.wt. PEG are hard & smooth tasteless. ACRYLATE POLYMER :- Marketed under trade mark . EUDRAGIT* EUDRAGIT:- It is cationic copolymer freely soluble in GIT fluid up to PH5 . These film are used for delayed action.
  42. 42. ENTERIC MATERIALS:- Why enteric coating is done? To protect acid labile drugs form gastric fluid E.g.:- Antibiotics. To prevent gastric distress E.g.:- sodium silicate. To provide a delayed release component. CELLULOSE ACETATE PHTHALATE:- Dissolve only above PH 5 CAP film are brittle (aqueous enteric coating) . Aquatic coating.  Acryl polymers:- EUDRAGIT L - soluble in intestinal fluid at
  43. 43. HYDROXY PROPYL METHEYL CELLULOSE PHTHALATE :- Marketed as HPMCP 5655,555. Soluble at lower PH (5to 5.5). Result in higher bioavailability. POLY ACETATE PHTHALATE :- Has PH dependent solubility . SOLVENT :- To dissolve or disperse the polymer.  Ideal characteristics of a solvent Should have rapid drying rate . Non toxic Aqueous solvent based coating are much performed than non aqueous organic solvent based coating.
  44. 44. PLASTICIZERS:-  Make polymers of & enhance flexibility .  Modify physical &*mechanical properties of film.  Reduce glass transition temperature of amorphous polymer & impart flexibility.  Recommended level of plasticizer rang 1-50% weight of film former.  The quality of polymer film is modified by :-  Internal plasticization - (Chemical change are made with in structure of polymers )  External plasticization - ( By using additives plasticizers )
  45. 45. COLORANT S:-  May be soluble in solvent or  suspended as insoluble powder. F or light shade :- 0.01%  For dark shade :- >2.0%
  46. 46. MISCELLANEOUS COATING SOLUTION COMPONENTS To provide a dosage form with a single characteristic, special materi als may be incorporated into a solution. Flavors and sweeteners are added to mask unpleasant odors or to develop the desired taste. For example, aspartame, various fruit spirits (organic solvent), water soluble pineapple flavor (aqueous solvent) etc. Surfactants are supplementary to solub
  47. 47. Antioxidants are incorporated to stabilize a dye system to oxidation and color change. For example oximes, phenols etc. Antimicrobials are added to put off microbial growth in the coating composition. Some aqueous cellulosic coating sol ution are mainly prone to microbial growth, and long-lasting storage of the coating composition should be avoided. For example
  48. 48. OPAQUANT EXTENDER:- TO INCREASE FILM COVERAGE . TO MASK COLOR OF TABLET CORE .
  49. 49. DEFECTS /PROBLEMS
  50. 50. PROBLEM ENCOUTERED DURING FILM COATING
  51. 51. PICKING :- A PICKING OF FILM MAY REMAIN ADHERED TO PAN . REASON:- LOCALIZED OVER WETTING REMEDY:- INCREASE DRYING AIR TEMPERATURE .  REDUTION IN LIQUID APPLICATION RATE .
  52. 52. PICKING DOES NOT OCCUR ALONE MUST HAVE ANOTHER TABLET TO BE STUCK WITH WHICH CALLED STICKING :- . STICKING IS THE DEFECT THAT THE BROKEN FILM COME PICKING TABLET AHD STICKS ON THE TABLET SURFACE. TWINNING :- TABLET WITH FLAT EDGES/FACES
  53. 53. MOTTLED COLOR :-  MIGRTION OF SOLUBLE DYE DURING DRYING .  REMEDY :- USE OF LAKE DYES ELIMINATION MIGRATION.  ORANGE PEEL EFFECT :-  INADEQUATE SPREADING OF COATING SOLUTION BEFORE DRYING  REASON:- TO RAPID DRYING HIGH SOLUTION VISCOSITY  RAMEDY:- THINING THE SOLUTION WITH ADDITIONAL SOLVENT.
  54. 54. FILLING:-  CAUSED BY APPLYING TO MUCH SOLUTION ,RESULTING IN A THICK FILM FILLS & NARROWS THE MONOGRAM OR IS BISECT .  EDGE WEAR :-  REASON :- TABLET CORE HAVING HIGH FRIABILITY.  RAMEDY:- WORN PUNCHES .
  55. 55. CHIPPING :- REASON:- THIS IS THE RESULT OF HIGH SPEED A FRIABLE TABLET .CORE A COATING SOLUTION THAT LACKS A GOOD PLASTICIZER.  FILM CRACKING:-  REASON :- IF INTERNAL STRESS IN FILM EXCEED  THE TENSILE STRENGTH OF FILM.  REMEDY:- TENSIL STRENGTH IS INCREASED BY  USING HIGH MOLEULAR WEIGHT POLYMER.
  56. 56. ROUGHESS:- REASON:- WHEN COATING IS APPLIED BY SPRAY SOME OF THE DROP DRY BEFORE REACHING THE TABLET BED . REMEDY:- MOVING THE NOZZLE CLOSE TO TABLET BED. BRIDGING:- DURING DRY ING FILM MAY SHRINK & CORNER OF BISECT ,RESULTING IN BRIDIENG OF SURFACE.. REMEDY:- INCREASE &CHANGE PLASTICIZER.
  57. 57. BLOOMING /DULL FILM:-  COATING BECOMES DULL  REASON:- TOO HIGH PROCESSING TEMPERATURE  LOW MOL.WT OF PLASTICIZER.  REMEDY:- DECREASE PLASTICIZER CONCENTRATION  & INCREASE MOL.WT OF PLASTICIZER.
  58. 58. OTHER PROBLEMS ENCOUNTERED DURING FILM COATING:- DUE TO EXCESSIVE MOISTURE WITH IN THE TABLET. WHICH PREVENTE COATING FROM ADHERING.
  59. 59. REFERENCES:- • Lachman/Lieberman’s “The Theory and Practice Of Industrial Pharmacy” Fourth Edition 2013, Edited by: Roop K Khar, SP Vyas, Farhan J Ahmad, Gaurav K Jain, CBS Publishers and Distributors Pvt Ltd, New Delhi. • Doornbos C and Hann P. Optimization Techniques in Formulation and Processing. In Encyclopedia of Pharmaceutical Technology. Swarbrick J and Boylan JC, Eds., Vol. II, Marcel Dekker, New York. 199 • Modern Pharmaceutics Fourth Edition, Revised and Expanded, Edited By G.S.Banker & C.T.Rhodes, Marcel Dekker pg387-389. • The Science & practice of Pharmacy, By Remington, Vol- 01, 21st Edition, Lippincott Publication.

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