compression coating

The assumption on colon-specific drug delivery system suffers from minor inherent problems. The development of novel into pH dependent and microbially triggered compression enteric  coated  tablets  was  done.  Capecitabine was used as a model drug. The core tablet was coated with acid soluble coating, Eudragit®S-100 which was compression coated with immediate release blend of drug containing microbial triggering polysaccharide, guar gum. Different combinations of polymers were selected to achieve drug targeting to the colon for the treatment  of  colorectal cancer. The novel – CODES successfully showed resistance to the gastric environment and exhibited no drug release in simulated intestinal fluid. In-vitro release studies for prepared  tablets  were carried out for 2 hours in 0.1 N HCl, 3 hours in pH 7.4 phosphate buffer and remaining in 6.8 pH phosphate buffer. In vitro studies revealed that it have limited drug release in stomach, small intestine and released maximum drug in the colonic environment.

The objective of this study was to develop and evaluate a pulsatile drug delivery system based on drug-containing core tablet, which were coated with a swelling layer. Core tablets of Salbutamol Sulphate were prepared by direct compression using a croscarmellose sodium as disintegrant, micro crystalline cellulose as diluent and other. Core tablets were evaluated for uniformity of weight and thickness, hardness, friability, disintegration and dissolution. Compression coating over the prepared core tablets were done using various grade of HPC. Different formulae S1 to S9 were prepared using different coat % weights gain and polymer ratio. The compression forces were kept constant by adjusting constant distance between the upper and lower punches. The prepared Salbutamol Sulphate tablets were evaluated for the Lag time and in vitro release characteristics at variant pH media mimicking the gastrointestinal media. The results showed that the developed core tablets of Salbutamol Sulphate comprised excellent physical characteristics and complied with the USP criteria. For the pulsatile system, a quick releasing core was formulated in order to obtain a rapid drug release after the rupture of the polymer coating. The lag time prior to the rapid drug release phase increased with increasing % coating level. Key word: disintegrant, swelling layer, pulsatile release tablets, compression coating, lag time.