Formulation and optimisation of Ozenoxacin topical nano-emulgel including a comprehensive methodology to qualify and validate the critical parameters of an in-vitro release test method and ex-vivo permeation test.

Objective: The purpose of this study was to formulate, optimise Ozenoxacin topical nano-emulsion using factorial design followed by to prepare and evaluate nano-emulgel using validated In-Vitro Release Testing (IVRT) technique for determination of Ozenoxacin release rate along with Ex-Vivo Permeation Testing (EVPT). Significance: Nano-emulgel are a proven delivery system for poorly soluble substances works by enhancing the solubility and bioavailability. Factorial design provides a systematic and efficient means to study the effect of multiple factors on responses. IVRT is an USP compendia technique utilised for performance analysis of semi-solid formulations. Methods: Nano-emulsion formulation optimisation was done with factorial design, evaluated for globule size and % entrapment efficiency. Nano-emulgels were characterized for assay, organic impurities, rheological behaviour, IVRT, EVPT & skin retention studies. IVRT validation was executed using vertical diffusion cells. Results: Ozenoxacin nano-emulsion was optimised with 1:1 ratio of Oil:S mix , 3:1 ratio of Surfactant:Co-Surfactant and 15000 RPM of homogenization speed which resulted 414.6 ± 5.2 nm globule size and 92.8 ± 2.1% entrapment efficiency. Results confirmed that IVRT and Reversed Phase - High Performance Liquid Chromatographic techniques were validated as per regulatory guidelines. In-vitro, ex-vivo drug release and skin retention from the optimized nano-emulgel formulation was comparatively higher (∼1.5 times) than that from the innovator (OZANEX TM ) formulation. Conclusion: Based on these results, Ozenoxacin nano-emulgel can be considered an effective alternative and was found to be stable at 40 °C/75% RH and 30 °C/75% RH storage condition for 6 months.