QbD Based Formulation Development and Optimisation of Ozenoxacin Topical Nano-Emulgel and Efficacy Evaluation Using Impetigo Mice Model

To formulate and optimize Ozenoxacin nano-emulsion using Quality by Design (QbD) concept by means of Box-Behnken Design (BBD) and converting it to a gel to form Ozenoxacin nano-emulgel followed by physico-chemical, in-vitro, ex-vivo and in-vivo evaluation. This study demonstrates the application of QbD methodology for the development and optimization of an effective topical nanoemulgel formulation for the treatment of Impetigo focusing on the selection of appropriate excipients, optimization of formulation and process variables, and characterization of critical quality attributes. BBD was used to study the effect of "% of oil, % of Smix and homogenization speed" on critical quality attributes "globule size and % entrapment efficiency" for the optimisation of Ozenoxacin Nano-emulsion. Ozenoxacin loaded nano-emulgel was characterized for "description, identification, pH, specific gravity, amplitude sweep, viscosity, assay, organic impurities, antimicrobial effectiveness testing, in-vitro release testing, ex-vivo permeation testing, skin retention and in-vivo anti-bacterial activity". In-vitro release and ex-vivo permeation, skin retention and in-vivo anti-bacterial activity were found to be significantly (p < 0.01) higher for the nano-emulgel formulation compared to the innovator formulation (OZANEX™). Antimicrobial effectiveness testing was performed and found that even at 70% label claim of benzoic acid is effective to inhibit microbial growth in the drug product. The systematic application of QbD principles facilitated the successful development and optimization of a Ozenoxacin Nano-Emulsion. Optimised Ozenoxacin Nano-Emulgel can be considered as an effective alternative and found to be stable at least for 6 months at 40 °C / 75% RH and 30 °C / 75% RH.

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, optimize 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 is 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 utilized for performance analysis of semi-solid formulations.

METHODS

Nano-emulsion formulation optimization was done with factorial design, evaluated for globule size and % entrapment efficiency (EE). Nano-emulgels were characterized for assay, organic impurities, rheological behavior, IVRT, EVPT, and skin retention studies. IVRT validation was executed using vertical diffusion cells (VDCs).

RESULTS

Ozenoxacin nano-emulsion was optimized with 1:1 ratio of Oil: Smix, 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 (OZANEXTM) formulation.

CONCLUSIONS

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.

Analytical method validation on simultaneous estimation of Ozenoxacin and Benzoic acid in pharmaceutical formulation

In this study, an accurate, simple, economical and precise Reversed-Phase High Pressure Liquid Chromatography (RP-HPLC) method was developed for the simultaneous estimation of Ozenoxacin and Benzoic Acid in a pharmaceutical cream formulation, according to the International Conference on Harmonisation (ICH) guidelines. Chromatographic separation was achieved by gradient elution, on RP-HPLC Instrument, equipped with column C8 (150 mm × 4.6 mm, 5 μm particle size) using Ultra Violet (UV) detector at 235 nm wavelength, by using Mobile Phase A: triethylamine, trifloroacetic acid and water (1:1:1000) and Mobile Phase B: methanol and Diluent: water, acetonitrile and triethylamine (500:500:1), at flow rate 0.8 mL min−1; injection volume of 20 μL; column oven temperature 45 °C and sample temperature: 25 °C; Run time: 15 min. All the validation parameters were within the acceptance criteria, as per ICH requirements, for Ozenoxacin and Benzoic acid. Consequently, this method has found to be validated, simple, rapid and successfully applicable, to the simultaneous estimation of Ozenoxacin and Benzoic acid by RP-HPLC, for routine analytical testing in quality control, with a run time of 15 min and for future research studies. Forced degradation of Ozenoxacin cream 1% w/w formulation was performed and found that validated method has stability indicating potential that needs to be further studied.