Formulation and rheological characterization of an antibacterial gel based on Hedera helix Algeriensis stabilized by xanthan gum

Abstract

This study aimed to formulate a natural gel containing triterpenic saponins as an antibacterial ingredient and xanthan gum as a gelling agent. Saponins were extracted from Algerian Hedera helix. The yield by microwave assisted extraction was about 1.22% for an extraction time of 10 min. The isolated saponins were identified by thin layer chromatography, foaming tests, Fourier transform infrared spectroscopy, and proton nuclear magnetic resonance spectroscopy. An antibacterial gel was then prepared and compared with a marketed gel for its rheological properties. In the optimized xanthan gel, saponins were introduced in order to contribute antimicrobial character. The prepared gels were then characterized in terms of pH, rheology and microbiology. The results showed that their characteristics were close to those of the reference product. The optimized gel was found stable over time and temperature, since the elastic and loss moduli remained constant. An in vitro analysis revealed very important antimicrobial activity against several bacterial strains.

Keywords

• saponins
• gel formulation
• xanthan
• rheology
• antimicrobial activity