Validation of UV Spectrophotometric Method for Quantifying Ketoconazole Encapsulated in Ethyl Cellulose Microspheres

Abstract

Ketoconazole (KZ) is an antifungal drug used to treat several mycoses. It has poor solubility and causes some adverse effects after its administration. For that reason, it has been included in various drug delivery systems such as polymeric microspheres. Ethyl cellulose is a water‐insoluble polymer widely used to encapsulate drugs because of its safety, good stability, easy fabrication, and cheapness. The amount of drug encapsulated per microspheres mass is a very important parameter to be precisely determined because it defines the mass of particles to be included in a single formulation dose. This work was aimed to validate an ultraviolet (UV) spectrophotometric method to quantify KZ encapsulated in ethyl cellulose microspheres. The KZ‐loaded microspheres were obtained by the emulsion − solvent evaporation method. The UV spectrophotometric method was validated following the ICH Guideline for validation of analytical procedures. The wavelength (247 nm) was selected from the spectrum of KZ (10 μg mL) in dichloromethane. The method was linear within the range 2–12 μg mL (slope: 0.0264; R2 = 0.9976). The accuracy was 99 ± 3, 98 ± 2, and 101 ± 2% for the low, medium and high range respectively. The intra‐assay relative standard deviation (RSD) was 1.8% while the inter‐assay RSD between days was 1.7%. The method, that is simple, rapid, precise, accurate and reproducible, was successfully applied to determine the content of KZ encapsulated in the ethyl cellulose microspheres.