Design and Evaluation of Controlled Release Chitosan-calcium Alginate Microcapsules of Anti Tubercular Drugs for Oral Use

Chitosan coated alginate microcapsules were developed as oral sustained delivery carriers for anti tubercular drugs in order to improve patient compliance, to reduce dose/dosing frequency in the management of tuberculosis (TB), which otherwise demands prolonged chemotherapy. Alginate–chitosan microparticles encapsulating three frontline anti-tuberculosis drugs (ATDs), rifampicin, isoniazide and pyrazinamide, were formulated by using ionotropic/external gelation method. Three different formulations containing rifampicin, isoniazide and pyrazinamide separately were prepared in the ratio of 1:2:2 (drug: sodium alginate: chitosan). The prepared microcapsules were evaluated by SEM analysis, size analysis, sphericity, drug content, encapsulation efficiency, swelling studies and mucoadhesion which were compared with that of pure drug. The microcapsules exhibited a slow and sustained release over a period of 72 hours. In-vitro release studies were carried out in pH 1.2 for 2 hours and then in pH 7.4 for 72 hours and the amount of drug released were 96.46, 95.33 and 97.27 from rifampicin, isoniazide and pyrazinamide microcapsules respectively where as the release rate for pure drugs was 95.46% (3hrs) for rifampicin, 98.99 %(30mins) for isoniazide and 96.44% (30mins) for pyrazinamide. Alginate–chitosan microcapsules hold promise as a potential natural biodegradable polymer-based oral ATD carrier for better management of Tuberculosis.