Effect of poloxamer on physicochemical properties of tacrolimus solid dispersion improving water solubility and dissolution rate

Abstract

Tacrolimus (TCR; also FK-506 and trade name prograf®), an antibiotic of macrolide family and a novel immunosuppressive agent, is a natural product of actinomycete Streptomyces tskubaensis. But TCR is poorly soluble in water (0. 012 mg/mL), so its bioavailability is low and irregular. The aim of this study is to characterize physicochemical properties of TCR and investigate the improvement of solubility and dissolution rate of TCR solid dispersion (SD) with poloxamer. TCR SDs, consisting of various grades and ratios of poloxamer were prepared by hot-melting method and were characterized by DSC, PXRD, and FT-IR. The dissolution profile and solubility of TCR from the SDs were evaluated. SD of TCR prepared with poloxamer 188 at the ratio of 1:1 by the hot-melting method resulted in a significant increase in TCR solubility and enhanced dissolution profile over the TCR crystalline powder. ? 2012 The Korean Society of Pharmaceutical Sciences and Technology.