A simple technique for entrapping rifampicin and isoniazid into liposomes

A method for the preparation of liposomes loaded with rifampicin and isoniazid is described. Optimal conditions were established; the lipid suspension was mixed with the aqueous solution of the drugs and was sonicated in a bath for 30 min at 50 degrees C. The optimum composition tested was phosphatidyl choline, cholesterol and cardiolipin in a molar ratio of 7:2:1. The separation of unloaded drug was performed by centrifugation through three successive Sephadex G-25 columns. The liposomes were multilamellar vesicles with a size ranging from 100-300 nm. The drugs were trapped in concentrations from 6.5-9.5 mg/ml. This method is suitable for preparation of liposomes in small laboratories.