SOLUBILITY OF FLUTICASONE PROPIONATE IN AQUEOUS SOLUTIONS MEASURED BY A METHOD AVOIDING ITS ADSORPTION TO EXPERIMENTAL TOOLS

Abstract

A method for determining fluticasone propionate (FLT) in 50% methanol using HPLC, the adsorption of FLT, a method for avoiding such adsorption to experimental tools, and the solubility of FLT in aqueous solutions were investigated. In the developed determination method, the retention time of FLT was approximately 6.8 min, and linear regression analysis gave a slope, intercept, and correlation coefficient of Y = 99.173X + 21.513, r = 0.99999. The values of intra-day and inter-day precision and accuracy in this method were acceptable. The lower limit of quantification was established to be 10 ng/mL. Adsorption of FLT to experimental tools made of glass and polypropylene was observed. The adsorption to conventional experimental tools was examined using 100 ng/mL FLT solution. The adsorption characteristics of FLT and a method to avoid such adsorption were determined from these results. The solubilities of FLT were measured by the method avoiding the effect of adsorption, which in water, 0.1 N HCl, and buffer solutions at pH 2, 4, 6, and 8 were 0.1 µg/mL. It was found from the result of a preliminary experiment that the solubility of FLT was improved by the addition of cycloexteins.