HPLC determination of clofazimine in tissues and serum of mice after intravenous administration of nanocrystalline or liposomal formulations

A simple HPLC method is described for the determination of clofazimine in m ouse tissues and in serum. The main application of the method was the deter mination of the drug in mouse tissues after i.v. administration of nanocrys talline suspensions or liposomal encapsulated clofazimine. Tissues were ext racted with a 10-fold (w/v) volume of an extraction solution consisting of methanol/glacial acetic acid 9:1 (v/v). Serum proteins were precipitated wi th a 2-fold volume of acetonitrile. Isocratic chromatography was performed using an anion exchange column (Nucleosil 100-5 SA, Macherey & Nagel) for s eparation. The mobile phase was a mixture of acetonitrile and 0.1 mol/l aqu eous phosphoric acid (75:25, v/v), adjusted to pH 2.9 with sodium hydroxide solution. Absorption of the eluate was monitored at 495 nm. The assay was precise, simple to perform and fast. Recovery from tissues was greater than or equal to 98%, from nanoparticles greater than or equal to 98%, and from liposomes greater than or equal to 96%. No interference was observed in ex tracts from mouse liver, spleen, lungs and human serum. (C) 1999 Published by Elsevier Science B.V. and International Society of Chemotherapy. All rig hts reserved.