Liposomes and PLG microparticles as sustained release antitubercular drug carriers--an in vitro-in vivo study.

Liposomes and PLG microparticles were investigated as sustained release antitubercular drug carriers for isoniazid (INH) and rifampicin (RIF). In vitro release of drugs from liposomes showed a sustained release of INH and RIF up to 4 weeks. PLG microparticles exhibited a sustained release of INH and RIF up to 6 and 49 days, respectively. In vivo drug disposition studies from liposomes indicated a sustained release of INH in plasma and various tissues up to 24 h and 5 days, respectively, while release of rifampicin was obtained for 24 and 72 h in plasma and various tissues. In vivo drug disposition studies from PEG-PLG microparticles indicated a sustained release of INH up to 9 and 27 days in plasma and various tissues, while rifampicin was detected in plasma and lungs up to 12 h and 27 days. Hepatotoxicity studies revealed no toxicity induced using biochemical tests. PLG microparticles exhibited a more sustained release of antitubercular drugs than a liposomal carrier system.