Tablet coats characteristics

Tablet coating is done for a variety of reasons. The tablet core may contain an active substance that imparts undesirable organoleptic qualities to the tablet. The active moiety of the tablet may be unstable to specific environmental conditions and may need protection. The core may need to be coated to meet marketing requirements. The coating may be needed to impart enteric properties or sustained-release characteristics to the active release profile. Typical coating processes require a solvent, organic or aqueous. Utilities required include compressed air, steam, and electrical service. Provisions should be made for air handling. The exhaust system used must be capable of handling the solvent used in this process.

Neural networks have also been used in Slovenia, to model the release characteristics of diclofenac [52] in China, to study release of nifedipine and nomodipine [53] and in Yugoslavia to model the release of aspirin [54], More recently, work in this area has been extended to model osmotic pumps in China [55] and enteric coated tablets in Ireland [56],... 

Lakes are prepared by adsorption or precipitation of a soluble dye on an insoluble substrate (e.g., alumina). They are useful in fatty products that have insufficient moisture to dissolve dyes (coated tablets, cake mixes, hard candies, chewing gum). Lakes are insoluble in most solvents including water, have high opacity, are easily incorporated in dry media, and show higher stability to light and heat. They are effective colorants for candies, pills, fats, and oils. The main characteristics and differences between lakes and dyes are well documented. ... 

Some tablets combine sustained-release and rapid disintegration characteristics. Products such as K-Dur (Key Pharmaceuticals) combine coated potassium chloride crystals in a rapidly releasing tablet. In this particular instance, the crystals are coated with ethylcellulose, a water-insoluble polymer, and are then incorporated into a rapidly disintegrating microcrystalline cellulose (MCC) matrix. The purpose of this tablet is to minimize GI ulceration, commonly encountered by patients treated with potassium chloride. This simple but elegant formulation is an example of a solid dosage form strategy used to achieve clinical goals. 

Coated tablet attributes Coating process characteristics... 

Staniforth JN, Reeves LA, Page T. Electrostatic powder coating of tablets I design and characteristics of a continuous coater prototype. Proceedings of the 13th Annual Meeting Exposition of AAPS, San Francisco, 1998. 

Pan coating with a Eudragit-PEG 400 mixture proved to be best technique. The relative ease of manufacture and the variety of release profiles attainable make pan coating with a Eudragit E 300-PEG 400 mixture a useful technique for obtaining sustained release tablets. Further studies will be necessary to assess the influence of Eudragit PEG ratio on ketoprofen release characteristics. 

FIGURE 3 Various process parameters and product characteristics associated with validation activity of typical coated tablet. 

Naproxen sodium tablets were used in an in vivo-in vitro evaluation with four different polymeric dispersions, cellulose acetate phthalate (CAP), cellulose acetate trimellitate (CAT), 50 50 CAP/CAT, and methacrylic acid copolymer [64], The study indicated that coating material that dissolves at a more acidic pH in vitro (such as CAT at pH 4.5) will also dissolve at a more acidic pH in vivo (i.e., the coating dissolves higher up in the GI tract). In addition, it was found that aging did not markedly affect dissolution characteristics of CAT or methacrylic acid copolymer-coated tablets. 

State the composition the name and amount of each active and inactive ingredient in the drug product in the form in which it is to be distributed (e.g., amount per tablet). Describe the dosage form full details as to type and physical characteristics (e.g. shape, color, coating, and hardness). 

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