Evaluation of gelation properties of the aqueous leaf extract of Cyclea peltata

Abstract

Biopolymers derived from natural sources have gained popularity in creating hydrogels which are useful in formulating hypoallergenic and cost-effective pharmaceutical products. Hydrogels are water swollen three-dimensional polymeric structures that facilitate free diffusion of liquids and molecules. These networks are synthesized by linking biopolymers via inherent intermolecular forces or through chemical cross-linking. In this initial investigation, we assessed the gelation potential of the aqueous extract of Cyclea peltata, a climbing shrub belonging to the family Menispermaceae. The study examined gelation under varying temperatures (10°C to 90°C) and pH levels (1 to 13) and with 0.2 mg/mL CaCl2 solution. Notably, gel formation did not occur at temperatures above 70°C or at the extreme pH values of 1 and 13. However, gels were successfully formed under both acidic and alkaline pH conditions, barring the aforementioned pH extremes. The most stable gel was formed at 30°C and pH 7 (CPLG15) exhibiting minimal syneresis of 1.1384 %. The resultant gels maintained a pH range of 4.8–6.6, regardless of solvent pH variations, suggesting a buffering effect. Introducing calcium shortened the gelation period but increased syneresis. Freeze-dried CPLG15 could form a gel when reconstituted with distilled water if stored at 2-8°C and retained its gel state withoutsyneresis or changes of organoleptic properties maximally up to a week.