Development and Validation of a UV-Spectrophotometric Method for Determination of Flucloxacillin Sodium in Capsules

Flucloxacillin (FLU) is a semi-synthetic penicillin active against many gram-positive bacteria such as streptococci and penicilinase-producing staphylococci, including methicillin-susceptible S. aureus. A simple, rapid, reproducible and cost-effective UV-spectrophotometric analytical method was validated to assay flucloxacillin sodium (FLU) in capsules. Measurements were taken at 274 nm using ultra-purified water as the solvent. This new method was validated in accordance with ICH requirements, which include linearity, precision, accuracy, specificity, robustness, detection and quantitation limits. The method demonstrated good linearity over the range of 50.0 to 100.0 mg L-1 FLU with a correlation coefficient (r) equal to 0.9998. The accuracy of the method was 100.09%. The precision demonstrated a relative standard deviation of less than 2.5%. The excipient in the capsules did not interfere with the assay. The results were satisfactory when compared with the literature. The proposed method might be applied in routine quality control in the pharmaceutical industries since it is precise, accurate, simple, economic and produces very low amounts of solvents and residues.