Formulation, characterization and wound-healing potential of emulgel and in-situ gel containing root extract of Saussurea lappa Clarke (Asteraceae)

Abstract

Purpose: To investigate the wound-healing potential of herbal formulations (emulgels and in situ gels) containing Saussurea lappa root extract  (SLRE) via excision wound induction in albino rats. Methods: Preliminary phytochemical analysis of the methanol extract of roots of Saussurea lappa (SLRE) was performed using standard  procedures. In vitro anti-inflammatory assay of SLRE was conducted using heat-induced hemolysis method at a concentration of 100 μg/mL. Acute  toxicity of SLRE was also evaluated in mice at a single dose of 1000 mg/kg for 24 h. Emulgels and in situ gels were prepared using different concentrations of SLRE and assessed for their organoleptic and physical properties. In vitro drug release studies of the prepared formulations were carried out by Franz diffusion cell and the data fitted into various pharmacokinetic models. Wound healing was assessed using excision wound induction (380 mm2) on dorsal surface of male albino rats. Each formulation (F4, F5, F6, G1, G2 and G3) and pyodine gel (standard) were applied topically (0.5 g) for 20 days. Wound contraction was measured every fourth day. Results: SLRE showed 42.8 % inhibition in heat-induced hemolysis on erythrocyte membrane model, compared to aspirin (positive control).  Moreover, SLRE did not cause mortality in mice at the given doses. All the formulations were stable after one month stability check at 40 °C for emulgels and at 25 °C for in situ gels. All the formulations followed first order drug release pattern. In situ gel (G3) exhibited better wound healing (100 ± 0.0028) than emulgel (F6, 99 ± 0.004) containing 5 g extract and standard pyodine gel (91 ± 0.014, p <0.05). Conclusion: The results indicate that in situ gel of SLRE exhibits significant wound healing in rats. Thus, the findings present a strategy for the formulation of gel products with better wound healing potentials. Keywords: Saussurea lappa, Wound healing, Emulgel, In situ gel, Herbal formulation