Published on April 10, 2011
Slide 1: S.B.S College Of Pharmacy Patti Tarn Taran Punjab143416 PRESENTED BY Monika S. M.PHARMACY, 2 nd SEMISTER PHARMACEUTICS PRESENTED TO, Dr. Nawazish Alam COATING TECHNOLOGY OFTABLETS 4/10/2011 1 Monika S.,"Dr.Nawazish Alam" CONTENTS: HISTORICAL PERSPECTIVE INTRODUCTION KEY FACTORS TYPES OF TABLET COATING - FILMCOATING - SUGAR COATING TABLET DEFECTS Advances in tablet coating CONCLUSION REFERENCES 4/10/2011 2 Monika S.,"Dr.Nawazish Alam" CONTENTS Slide 3: HISTORICAL PERSPECTIVE Based on Islamic literature (850-923) “Rhazes” Sugar coating (1800, 1837-1840) for Cubeb and Copaiba Dr. “Dale wurster” (1950)-Air suspension coater Abbott laboratories (1953) Accela cota, Hi-coater, Dria coater 4/10/2011 3 Monika S.,"Dr.Nawazish Alam" Slide 4: WHAT IS TABLET COATING? WHY COAT TABLETS? INTRODUCTION 4.To Mask Color, Odour, Taste of the drug 3.Stability 5.Control the release 6.Protection from GI fluids Definition Of coating 1.Identification 2.Improve elegance 4/10/2011 4 Monika S.,"Dr.Nawazish Alam" Slide 5: KEY FACTORS TABLET PROPERTIES - Shape - Tolerance - Surface area COATING PROCESS - Equipments - Parameters - Facility and ancillary equipment - Automation COATING COMPOSITION - Polymers - Solvents - Plasticizers - Colorants 4/10/2011 5 Monika S.,"Dr.Nawazish Alam" Slide 6: Conventional Pan Systems Perforated Pans Systems Fluid Bed Systems 4/10/2011 6 Monika S.,"Dr.Nawazish Alam" COATING PROCESS Equipments Parameters Air Capacity Coating Composition Tablet Surface Area Equipment efficiency Spray application systems High-pressure air automated systems Low pressure air automated systems Slide 7: CONVENTIONAL PANS Standard Coating Pan Immersion-tube system Glatt Immersion sword system Pellegrini pan system 4/10/2011 7 Monika S.,"Dr.Nawazish Alam" Slide 8: PERFORATED PANS Accela cota system Hi-coater system 4/10/2011 8 Monika S.,"Dr.Nawazish Alam" Slide 9: PERFORATED PANS (continue…) Dria coater pan Glatt coater 4/10/2011 9 Monika S.,"Dr.Nawazish Alam" Slide 10: FLUID BED COATING SYSTEMS 4/10/2011 10 Monika S.,"Dr.Nawazish Alam" Slide 11: SPRAY APPLICATION SYSTEMS High-pressure airless automated systems Low-pressure air automated systems 4/10/2011 11 Monika S.,"Dr.Nawazish Alam" Slide 12: 4/10/2011 Monika S.,"Dr.Nawazish Alam" 12 High pressure airless system Low pressure air atomized system Difference in the system is atomization of liquid. Airless system - Liquid pumped at high pressure (250-3000 psig) through small orifice, fine spray. Degree of atomization depends on - Fluid pressure - Orifice size - Viscosity of liquid Air atomized - Liquid pumped through large orifice at low pressure (5-50 psig). Air contacts liquid stream at tip of atomizer and fine spray is produced. Controlling variables - Fluid pressure - Fluid cap orifice - Viscosity of liquid - Air pressure - Air cap design Choice depends on coating solution composition for a particular product. Types of coating processes : Three main types are used in the pharmaceutical industry today; - Film coating - Sugar coating - Compression coating 4/10/2011 13 Monika S.,"Dr.Nawazish Alam" Types of coating processes Slide 14: 4/10/2011 Monika S.,"Dr.Nawazish Alam" 14 1- Film coating (the most popular today) It involves the deposition, usually by spraying method, of a thin uniform film of a polymer formulation surrounding a tablet. Slide 15: TYPES OF FILM COATING FILM COATING Pan pour method Pan spray method Methodsof film coating 4/10/2011 15 Monika S.,"Dr.Nawazish Alam" Slide 16: Film coating formulation (Composition of the coating liquid) 1- Polymer 2- Plasticizer 3- Colorants 4- Solvent (vehicle): Examples: water, ethanol, methanol, isopropranol, chloroform, acetone, methylethyl ketone, and methylene chloride 4/10/2011 Monika S.,"Dr.Nawazish Alam" 16 Slide 17: Ideal characters of coating material Solubility in the coating solution Solubility required for intended use- Free water solubility, Slow water solubility, pH- dependent solubility Capacity to produce elegant looking product Stability in presence of water, heat, moisture, air, and substrate being coated and no change in properties with aging. Essentially no color, odor, or taste Compatibility with common coating solution additives Nontoxic and ease of application Resistance to cracking and should act as barrier No bridging or filling of the debossed tablet surfaces by the film former Ease of printing procedure on high-speed equipment Low cost & Ease of application without specialized equipment 4/10/2011 Monika S.,"Dr.Nawazish Alam" 17 Slide 18: 4/10/2011 Monika S.,"Dr.Nawazish Alam" 18 Slide 19: PLASTICIZERS Internal plasticizers : Chemical modification of the polymer that alters the physical properties. Degree of substitution Type of substitution Chain length. External plasticizers : They are non-volatile or the other polymer, which when include with primary polymeric film former, changes the Flexibility Tensile strength, or Adhesion properties of the resulting film. 4/10/2011 19 Monika S.,"Dr.Nawazish Alam" Slide 20: Concentration Of Plasticizer Expressed As - The amount of polymer being plasticized. Recommended Level of Plasticizer : 1 to 50% by weight of the film former. EXAMPLES Castor oil; propylene glycol of 200 and 400 series; and surfactants eg; Tweens; Spans; and organic acid esters. Water- soluble plasticizer : PEG, propylene glycol. Organic- soluble plasticizer : castor-oil and Spans. 4/10/2011 20 Monika S.,"Dr.Nawazish Alam" Slide 21: COLORANTS Colorants may be soluble in the solvent system or suspended as insoluble powders. Used to provide distinctive color and elegance to a dosage form. To achieve proper distribution of suspended colorants in the coating solutions requires the use of fine-powdered colorants (< 10 microns ). Most of colorants are synthetic DYES or LAKES OF DYES approved by the FD&C and D&C. 4/10/2011 21 Monika S.,"Dr.Nawazish Alam" Slide 22: LAKES : derived from dyes by precipitating with carriers. Eg ; alumina or talc. Lakes contains 10 to 30 % of the pure dye content. For very light shade, concentration : less than 0.01 %. For dark shade, concentration : more than 2.0 % Examples Inorganic materials: iron oxides Natural coloring materials :Anthocyanins, caramel, carotenoids, chlorophyll, indigo, flavones, turmeric, and carminic acid. Various concentrates promoted as achieving less lot-to-lot color variation Opalux – Opaquant color concentrate for sugar coating. Opaspray- Opaque color concentrate for film coating. Opadry – Complete film coating concentrate 4/10/2011 22 Monika S.,"Dr.Nawazish Alam" Slide 23: OPAQUANT-EXTENDERS These are very fine inorganic powders used in the coating solution formulation to provide more pastel colors and increase film coverage. Opaquant provides a white coating or mask the color of the tablet core, and thus the less amount of the colorants are required. Examples: Silicates (talc, aluminium silicate); Carbonates (magnesium carbonate); Sulfates (calcium sulfate); Oxides (Mg oxides) 4/10/2011 23 Monika S.,"Dr.Nawazish Alam" ENTERIC COATING: The technique involved in enteric coating is protection of the tablet core from disintegration in the acidic environment of the stomach by employing pH sensitive polymer, which swell or solubilize in response to an increase in pH to release the drug. Aims of Enteric protection : To mask taste or odour Protection of active ingredients, from the acidic environment of the stomach. Protection from local irritation of the stomach mucosa. Release of active ingredient in specific target area within gastrointestinal tract. 4/10/2011 24 Monika S.,"Dr.Nawazish Alam" ENTERIC COATING Slide 25: Enteric Coating 4/10/2011 25 Monika S.,"Dr.Nawazish Alam" Examples of enteric coated OTC products : Examples of enteric coated OTC products Enteric coated aspirin E.g. Micropirin ® 75mg EC tablets Enteric coated peppermint oil E.g. Colpermin ® Monika S.,"Dr.Nawazish Alam" 26 4/10/2011 Slide 27: 4/10/2011 Monika S.,"Dr.Nawazish Alam" 27 Slide 28: - Typically, tablets are sugar coated by panning technique, using traditional rotating sugar-coating pan with a supply of drying air (thermostatically controlled). - The pan is automatically rotated, allowing tablets to tumble over each other while making contact with the coating solutions which are gently poured or sprayed, portion wise onto the tablets with warm air blown to hasten drying. Each coat is applied only after the previous coat is dried. 4/10/2011 Monika S.,"Dr.Nawazish Alam" 28 Slide 29: Simplified representation of sugar coating process 4/10/2011 Monika S.,"Dr.Nawazish Alam" 29 Slide 30: 4/10/2011 Monika S.,"Dr.Nawazish Alam" 30 Slide 31: SUGAR COATING Seal coating Sub coating Smoothing Color coating Polishing Printing 4/10/2011 31 Monika S.,"Dr.Nawazish Alam" Slide 32: 1- Sealing (Waterproofing) This involved the application of one or more coats of a waterproofing substance in the form of alcoholic spray, such as pharmaceutical Shellac (traditionally) or synthetic polymers, such as CAP. ( Unless a modified-release feature needs to be introduced, the amount of the sealing coat applied should be carefully calculated so that there is no negative effect on the drug release characteristics in case of immediate release product.) (WHY Sealing?) a- Sugar-coatings are aqueous formulations which allow water to penetrate directly into the tablet core and thus potentially affecting product stability and possibly causing premature tablet disintegration. b- Application of many coats of partially or completely water-insoluble polymers in this step, enables sugar-coated product to exhibit modified-release pattern (extended release or delayed "enteric"- release characteristics). 4/10/2011 Monika S.,"Dr.Nawazish Alam" 32 Slide 33: 2. Subcoating - Large quantities of sugar-coatings are usually applied to the tablet core (typically increasing the tablet weight by( 50- 100%) WHY? In order to round off the tablet edge. Much of this material build-up occurs during this stage and is achieved by adding a bulking agent such as Calcium carbonate, to the sucrose solution. - Antiadherents e.g. Talc may be added after partial drying to prevent sticking of the tablets together. 4/10/2011 33 Monika S.,"Dr.Nawazish Alam" Slide 34: 3- Smoothing The subcoating stage results in tablets with rough surfaces. To facilitate the color application (which requires smooth surface), subcoated tablets are smoothed out by a thick sucrose syrup coating. 4 - Coloring Color coatings usually consist of thin sucrose syrup containing the requisite coloring materials. (water-soluble dyes or water-insoluble pigments may be used) This step must be done into a clean pan deprived of any residues from the previous operations. 4/10/2011 34 Monika S.,"Dr.Nawazish Alam" Slide 35: 5- Polishing After the coloring step, the tablet surfaces tend to be smooth but somewhat dull in appearance. To achieve glossy finish, final stage involving application of waxes (beeswax carnuba wax) is employed. 6- Printing Different tablets could be identified by manufacturer' logo,product name, dosage strength or other appropriate code.For sugar-coated tablets, such identification could be only achieved by printing process using special edible inks. 4/10/2011 35 Monika S.,"Dr.Nawazish Alam" Example of sugar coated tablets : Example of sugar coated tablets Brufen® POM Available in 200mg and 400mg strength Premarin® POM Conjugated oestrogens 625mcg (maroon) and 1.25mcg (yellow) Colofac ® P Mebeverine hydrochloride 100mg Round, white, sugar coated Kalms ® GSL 45mg Hops powder,90mg Gentian powdered extract, and 135mg Valerian powdered extract Monika S.,"Dr.Nawazish Alam" 36 4/10/2011 Slide 37: 4/10/2011 37 Monika S.,"Dr.Nawazish Alam" Summary of Polymers used in pharmaceutical formulations as coating materials.: 4/10/2011 Monika S.,"Dr.Nawazish Alam" 38 Summary of Polymers used in pharmaceutical formulations as coating materials. Polymer Trade name Application Shellac EmCoat 120 N Marcoat 125 Enteric Coatings Taste/Odor Masking Cellulose acetate Aquacoat CPD® Sepifilm ™ LP Klucel ® Aquacoat ® ECD Metolose ® Enteric Coatings Taste masking Sustained release coating Sub coat moisture and barrier sealant pellet coating Polyvinylacetate phthalate Sureteric® Enteric Coatings Methacrylate Eudragit® Enteric Coatings Sustained Release Coatings Taste Masking Moisture protection Rapidly disintegrating Films Slide 39: 3- Compression-coating of tablets Although less popular, it gained increased interest in recent years for creating modified-released products involves the compaction of granular materials around preformed tablet core using specially designed tableting equipment. Compression coating is a dry process. 4/10/2011 Monika S.,"Dr.Nawazish Alam" 39 Slide 40: 4/10/2011 Monika S.,"Dr.Nawazish Alam" 40 Slide 41: 4/10/2011 Monika S.,"Dr.Nawazish Alam" 41 Slide 42: TABLET DEFECTS STICKING AND PICKING ROUGHNESS ORANGE PEEL EFFECTS BRIDGING AND FILLING BLISTERING HAZING/DULL FILM COLOR VARIATION CRACKING 4/10/2011 42 Monika S.,"Dr.Nawazish Alam" Coating Problems: picking/chipping roughness sticking film cracking/peeling 4/10/2011 43 Monika S.,"Dr.Nawazish Alam" Coating Problems Slide 44: 4/10/2011 Monika S.,"Dr.Nawazish Alam" 44 BRIDGING & FILLING ORANGE PEEL EFFECT Slide 45: Advances in tablet coating 4/10/2011 45 Monika S.,"Dr.Nawazish Alam" Slide 46: SPECIALIZED COATING TECHNIQUICS In this, cores to be coated are held in a suitable device eg: baskets Dipped into coating solution and then dried taking care to prevent adherence to one another. For obtaining more perfect or heavier coats the dipping and drying steps may be repeated several times one after another. Several dipping arrangements are obtainable, amongst them the sophisticated devices comprise tiny suction tubes, which hold the individual tablets apart until drying is accomplished. Before proceeding to coat additional tablets or begin recoating cycles . DIP-COATING 4/10/2011 46 Monika S.,"Dr.Nawazish Alam" Slide 47: SPECIALIZED TECHNIQUICS (continue…) Electrostatic coating is employed for applying films of electro- conductive materials. In this, an ionic charge is imparted to the core and an opposite charge to the coating material. This technology ensures thin, continuous and electronically perfected film to the surface. ELECTROSTATIC-COATING 4/10/2011 47 Monika S.,"Dr.Nawazish Alam" Slide 48: SPECIALIZED TECHNIQUICS (continue…) LAMINATED-COATING Laminated coating provides multiple layers for incorporation of medicament; for example Repeat-action tablet, here a portion of the drug is kept in outer lamella or coating Enteric tablet, here one drug could be made available for gastric absorption while another for release in intestine Buccal-swallow tablet, this could first be administered sublingually, and upon a signal, such as release of flavour from the inner core, the same may be swallowed as a normal peroral tablet. 4/10/2011 48 Monika S.,"Dr.Nawazish Alam" Slide 49: SPECIALIZED TECHNIQUICS (continue…) VACCUM FILM-COATING This employs a specially designed baffled pan, which is water-jacketed and could be sealed to achieve vacuum. Tablets are placed in the sealed pan, the vacuum is applied and the coating material is introduced through airless hydraulic spray system. Since the pan is completely sealed. Organic solvents could be effectively used with minimal environmental or safety concer n. 4/10/2011 49 Monika S.,"Dr.Nawazish Alam" Slide 50: ADVANCED TECHNIQUICS SUPERCELL-COATING Supercell coating technology is an invention of Niro Pharma, which uses a small modular design where tablets are coated in batches ranging from 30 to 40 grams, and which is amenable to linearly scale up to the production capacities. In this, typically tablets are coated with coating spray in the same direction as the drying gas, hence, resulting in a more efficient process. 4/10/2011 50 Monika S.,"Dr.Nawazish Alam" Slide 51: ADVANCED TECHNIQUICS SUPERCELL-COATING (continue…) 4/10/2011 51 Monika S.,"Dr.Nawazish Alam" DRYCOATING: Dry coating avoids the use of water or, at least, allows it to be reduced to very small amounts with respect to the coating material, thus overcoming the need for time- and energy-consuming drying phases, as well as possible drug stability issues. In this technology, powdered coating materials are directly coated onto solid dosage forms without using any solvent, and then heated and cured to form a coat. 4/10/2011 52 Monika S.,"Dr.Nawazish Alam" DRYCOATING CURRENT DRY COATING TECHNOLOGIES: Plasticizer-dry-coating Heat-dry-coating Plasticizer-electrostatic-heat-dry-coating 4/10/2011 53 Monika S.,"Dr.Nawazish Alam" CURRENT DRY COATING TECHNOLOGIES PLASTICIZER DRY COATING: 4/10/2011 54 Monika S.,"Dr.Nawazish Alam" PLASTICIZER DRY COATING Film formation in the plasticizer-dry-coating The film formation is the combined response of improved viscous flow and particle deformation resulted from plasticizer and heat. Applications - Both tablets and pellets can be coated. Limitations Coat thickness increases with increasing plasticizer concentration. However,surplus plasticizer leads to very soft or sticky films. Slide 55: (1) rotating disk; (2) infrared lamp; (3) powder feeder; (4) temperature probe; (5) coating tablets; (6) glass cover Heat-Dry-Coating 4/10/2011 Monika S.,"Dr.Nawazish Alam" 55 Slide 56: The advantages of heat-dry-coating include abandoning plasticizer for lower T g film-forming polymers or avoiding high concentrations of plasticizer because of pre-plasticization. However, it is still a challenge for heat-dry-coating technology to get a smooth, uniform and thick coating only by the help of heat-based adhesion. 4/10/2011 56 Monika S.,"Dr.Nawazish Alam" Plasticizer-Electrostatic-Heat-Dry-Coating: Coating process comprises the steps Positioning pre-heated solid dosage forms in a chamber of a rotatable, electrically grounded pan coater Spraying powdered coating materials and plasticizer on the solid dosage forms in the pan coater during rotation there of for a pre-selected length of time using an electrostatic spray gun Curing the coated solid dosage forms to form continuous, uniform and flexile coats. It is an integration of five kinds of “forces” : - Softening or melting effects - Wetting - Electrostatic attraction forces - Hydrodynamic force - Mechanical force. These are combined to enhance the adhesion of powdered coating materials to solid dosage surface. 4/10/2011 57 Monika S.,"Dr.Nawazish Alam" Plasticizer-Electrostatic-Heat-Dry-Coating Slide 58: Applications Conventional coating pharmaceutical polymers,such as Eudragit RS, Eudragit RL, Eudragit L, Eudragit EPO in combination with standard excipients were successfully coated onto tablets and beads. Produce smooth and uniform coating surfaces with controlled coating thickness on both larger dosage forms and smaller ones. Limitations Particularly applicable for pharmaceutical coating only with a single colour. 4/10/2011 58 Monika S.,"Dr.Nawazish Alam" Slide 59: CONCLUSION 4/10/2011 59 Monika S.,"Dr.Nawazish Alam" Slide 60: ADVANTAGES OF TABLET COATING Enhance palatability, mask unpleasant taste, odour and color of the API Increase the stability Increase the mechanical integrity Enhance the elegance Protect the patient Modify the drug release profile Avoid the side effects 4/10/2011 60 Monika S.,"Dr.Nawazish Alam" Slide 61: REFERENCES 4/10/2011 Monika S.,"Dr.Nawazish Alam" 61 www.pubmed.com www.wikipedia.com www.google.com websites The science and Practice of Pharmacy, Remington Volume 1 The Theory and Practice of Industrial Pharmacy by A. Lachman, 3 rd Edition Pharmaceutical Dosage forms by Liberman, Volume 3 Slide 62: THANK YOU FOR YOUR ATTENTION 4/10/2011 62 Monika S.,"Dr.Nawazish Alam"