Preparation and Evaluation of Topical Microemulsion System Containing Metronidazole

Abstract

Metronidazole is a synthetic nitroimidazole derived with antimicrobial and anti-inflammatory properties. The aqueous solubility of this drug is poor which results from low bioavailability. Limited effects on the removal of bacteria are shown in the local administration of plain metronidazole. The microemulsion system proves the efficacy of solubility and dissolution improvement of poorly watersoluble drugs such as metronidazole. The objective of this project work is to prepare and evaluate metronidazole containing topical water-in-oil microemulsion and to compare its effectiveness to other commercially available products. In this formulation, tween 80 is used as a surfactant and PEG 400 is used as a co-surfactant. In the oil phase, isopropyl myristate is used. Distilled water is used as the hydrophilic phase. The formulation of metronidazole containing microemulsion was evaluated for physicochemical parameters like pH, viscosity, conductivity, accelerated stability studies. In vitro release study was also performed to evaluate the release kinetics.

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“…After completion of phase I, formulation faced the next Phase II centrifugation at 5000 rpm for the time period of 30 minutes. After that, the microemulsion was checked for its physical instability like any phase separation, cracking or creaming 22 . In Phase III, the formulation was subjected to three freeze-thaw cycles,in which the formulation was freezed at − 04°C for 48 h, subsequently thawing it at 40 °C for 48 h 23 .…”