Effect of different Co-polymers on Sodium Alginate Microcapsules Containing Isoniazid

The present investigation was designed to develop, characterize and evaluate mucoadhesive microcapsules of isoniazid employing various mucoadhesive polymers for prolonged gastric intestinal absorption. Sodium alginate is an anionic polymer which can be easily cross-linked with calcium chloride. This is because the calcium ions are bound to carboxylate residues of both mannuronic acid and glucournic acid which are components of sodium alginate. The complexation between calcium ions and sodium alginate leads to controlled release of drugs. Three different formulations were prepared with core: coat ratio 1:2 and by using three different co-polymers in the ratio of 5:1(polymer: co-polymer) by employing orifice ionic gelation method. The method produced discrete, free flowing and spherical microcapsules ratios. The prepared microcapsules were evaluated for SEM analysis, sieve analysis, drug content, encapsulation efficiency, swelling studies and compared with pure drug. The microcapsules obtained were spherical, discrete and free flowing. The release depended on the type of copolymer and size of microcapsules. In-vitro release studies were carried out in pH 7.4 and 20.83%, 32.40% and 51.54% of the drug was released from F1 (sodium alginate+methyl cellulose), F2 (sodium alginate+Hydroxy propyl methyl cellulose) and F3 (sodium alginate+sodium carboxy methyl cellulose) respectively upto 12 hrs. Drug release was found to be diffusion controlled and followed first order kinetics. The prepared microcapsules showed sustained release over a period of 12 hrs.