Evaluation of Post-Reconstituted Flucloxacillin Dry Powder for Suspension in Nakuru Town, Kenya

Beta-lactam antibiotics are compounds which are commonly used to treat variety of bacterial infections. The β-lactam ring is readily hydrolyzed under varied pH and elevated temperature conditions. This degradation can result in subtherapeutic dosages and development of antimicrobial resistance. Flucloxacillin powder for suspension is among the most prescribed β- lactam antibiotics in Kenya. This study aimed to evaluate the effect of storage temperature on the stability of pharmaceutical equivalents of flucloxacillin dry powder for suspension. Reconstituted samples of flucloxacillin dry powder for suspension were stored in three temperature conditions: cold (4˚C), room (25˚C), and intermediate (30˚C). The content of flucloxacillin was determined by use of UV Spectroscopy at a wavelength of 219nm. An antimicrobial test was performed to determine the susceptibility of Staphylococcus aureus (a Gram-positive) and Escherichia coli (Gram-negative) to flucloxacillin using the Disk Diffusion method. The stability of the samples was evaluated every 2 days up to 10 days. The UV spectrum results showed a decreasing trend in flucloxacillin content over the 10 days of analysis. The microbial analysis results indicated that flucloxacillin retained its antimicrobial activity best under cold storage conditions. The zones of inhibition for Staphylococcus aureus for brand A at day 7 were 33.105mm, 31.055mm and 23.055mm at 40C, 250C and 300C respectively. The decrease in content and antimicrobial activity of flucloxacillin samples stored at 250C and 300C temperatures indicates that non-compliance with prescribed storage conditions may lead to subtherapeutic level dosing and contribute to poor treatment outcomes.