Design and in vitro characterization of a topical nanoemulsionenriched hydrogel of econazole nitrate

Abstract

Background/Objective: The aim of the study was to prepare a nanoemulsion (NE)-enriched hydrogel of econazole nitrate (EC) for a topical broad-spectrum antimycotic application. EC is classified as a Biopharmaceutical Classification System Class IV (low permeability, low solubility) drug. Nanotechnology is one of the most important approaches to improve drugs solubility and permeability. Methods: Depending on solubility study of EC in NE components which include oils (peppermint oil, eucalyptus oil, and olive oil), surfactants (Tween 40, Brij 35, and Ceto stearyl alcohol), and co-surfactants (Propylene glycol, PEG 400, and Glycerol); peppermint oil was selected as the oil phase. Tween 40 and propylene glycol were selected as the surfactant and co-surfactant, respectively. Deionized water was used as an aqueous phase. A phase diagram was prepared with a 5:1 weight ratio of tween 40 to propylene glycol. One percent of EC was loaded into the selected NE system and combined with hydrogel consisting of carbopol 934 or HPMC as gelling polymer at three different percentages. Evaluation and in vitro release of the product were done. Results: NE Formula (F10) which is composed of 10% w/w of each the oil and surfactant mixture was selected as optimum NE which shows a particle size of 80.57 nm and acceptable viscosity and pH (5.65). Formula (G6) which is composed of NE (F10) combined with hydrogel 3.5% HPMC shows satisfactory physical properties with the complete and prolonged release over 8 hours. Conclusion: The results suggest that the prepared NE-enriched hydrogel can be considered as a promising delivery system for class IV antifungal drug.