Formulation of microemulsions for dermal delivery of Cephalexin

Introduction: Cephalexin monohydrate (CEM) is mostly used because of its activity against both the gram-positive and gram-negative microorganisms for infections. Microemulsions offer numerous advantages for dermal delivery of drugs. Objective: The objective of the present study was to prepare novel CEM loaded microemulsions and to characterize formulations, to evaluate their in vitro release profiles and antibacterial activities. Method: CEM loaded formulations [0.02% (w/w)] were characterized according to their droplet size, zeta potential, PDI, pH, electrical conductivity and viscosity. In addition, in vitro drug release studies and antibacterial activity tests were performed. Results: The developed CEM loaded microemulsions (M1 and M2) achieved narrow droplet size distribution (152.75±4.85 and 128.05±9.22), low PDI (0.364±0.05 and 0.489±0.06), suitable pH (5.28-4.84) and conductivity (342±4.472-374±5.477 µS/cm). Zeta potential was measured as 0.209±0.041 and 0.141±0.024 mV. M1CEM showed 100% release at the 7th hour and was provided almost the same zone diameter as CEM solution when evaluated for antibacterial activity. Conclusion: Overall, it was concluded that microemulsions might be beneficial in improving dermal delivery of CEM for the treatment of skin and soft tissue infections.