Formulation development and in vitro assessment of metronidazole emulgels prepared with natural polymers

Abstract

In order to enhance topical drug delivery, the current study designed and assessed metronidazole emulgels using xanthan gum and guar gum, two natural gelling agents. FTIR analyses verified the drug-polymer compatibility. Metronidazole's λmax was determined to be 273 nm, demonstrating compliance with Beer-Lambert's law. The viscosity (603±15 cP) and pH (7.2±0.1) of the guar gum-based emulgel were higher than those of the xanthan gum-based formulation (497±15 cP, pH 6.8±0.1). The guar gum formulation demonstrated superior spreadability and extrudability (7.0±0.1 cm, 10.9±0.2 N) compared to xanthan gum emulgel (6.0±0.2 cm, 12.8±0.3 N). With xanthan gum emulgel releasing 97.2% guar gum emulgel releasing 94.7%, in vitro release studies using Franz diffusion cells demonstrated sustained drug release over eight hours. These results show that both formulations are appropriate for topical application, with guar gum offering better consistency and handling and xanthan gum favoring quicker drug diffusion.