Nkanga and Krause have published in Nature Scientific Reports their recent development of a novel anti-tubercular drug delivery system. Isoniazid-hydrazone-phthalocyanine conjugate (Pc-INH, see the structure above) was complexed by gamma-cyclodextrin (γ-CD) then encapsulated by liposomes using crude soybean lecithin by means of a simple organic solvent-free method, heating method (HM).
The HM-liposomes afforded good encapsulation efficiency (71%) for such a large Pc-INH/γ-CD complex (PCD) system. The stability and properties of the PCD-HM-liposomes look encouraging; with particle size of 240 nm and Zeta potential of −57 mV that remained unchanged upon storage at 4 °C for 5 weeks. The release study performed in different pH media revealed controlled release profiles that went up to 100% at pH 4.4, from about 40% at pH 7.4. This makes PCD-liposomes a promising system for site-specific anti-tubercular drug delivery, and a good example of simple liposomal encapsulation of large hydrophobic compounds.