Formulation, in Vitro Characterization and Anti- Tuberculosis Investigation of Isoniazid Nanocapsules

Purpose Tuberculosis (TB) is a major cause of mortality worldwide. The most commonly used first-line anti-TB drugs in the treatment of TB are rifampicin and isoniazid. The aim of this study was to formulate and evaluate the anti-mycobacterium activity of isoniazid (INH) nano formulations against mycobacterium isolates ( M. smegmatis and M. bovis ). Methods A 10 g quantity of the lecithin powder was placed in a beaker and 50 mL quantity of water added and heated on a water bath at 55 ^o C for 30 minutes. The oil and water phases were separated by centrifugation at 3000 rpm for 30 minutes. The gum/crude lecithin was dried in vacuum oven for 1 hour at 40 ^o C. The solvent and lecithin were separated by decantation. The acetone was removed by heating at low temperature at 40 ^o C and the powdered lecithin was packaged in screw-capped containers until further use. Results The percentage yield of the extracted lecithin ranged from 31.0±0.31% to 35.0±0.32%. The differential scanning calorimetry (DSC) thermograph of pure INH was 121.8 ^o C. The drug content of isoniazid formulation using extracted lecithin (IEL) and isoniazid formulation using reference lecithin (IRL) ranged from 96.4±0.29% to 93.5±0.94% respectively. The INH nano capsule formulations showed significantly ( p < 0.05) lower MICs (0.03 µg/mL) than the reference commercial capsule of INH (0.05 and 0.10 µg/mL) against M. smegmatis and M. bovis isolates, respectively. Conclusion The chitosan-fortified nano capsule formulation of INH has potentials for further exploration and development for enhanced bioavailability and application against MDR-TB.