Development and Evaluation of Sea Buckthorn Hippophae rhamnoides L Seed Oil Nanoemulsion Gel for Wound Healing

Abstract

xv newlineAbstract newlineObjective: To develop nanoemulsion gel of Sea Buckthorn (SBT) seed oil and evaluate its wound healing activity. newlineMethods: The nanoemulsion formulations of SBT seed oil were developed by spontaneous emulsification method and characterized in terms for stability, conductivity and compatibility studies. The selected nanoemulsion formulations were characterized for percentage transmittance, globule size, polydispersity index as well as surface morphological studies using TEM. The optimized nanoemulsion batch was further subjected to in-vitro evaluation to develop a stable nanoemulsion gel. The optimized nanoemulsion gel of SBT seed oil was subjected to in-vivo wound healing, ex-vivo skin penetration, antibacterial and antifungal studies. newlineResults: The optimized nanoemulsion batch NEA1 consisted of SBT seed oil and Smix Cremophor® RH 40: Span 80 in the ratio of 1:1. The formulation had good stability, high conductivity and compatibility. The formulation had spherical shaped non-aggregated globules, percentage transmittance of 97 % ± 0.62 % and mean globule size of 52.22 ± 0.62 nm. The selected nanoemulsion formulation NEA1 was further incorporated into two different concentration of Carbopol 940 (0.5% w/w and 1% w/w) to develop nanoemulsion gels so as to enhance the contact time and viscosity of the nanoemulsion formulation. The final NG2 nanoemulsion gel formulation was further selected on the basis of in-vitro parameters viz., rheology, spreadability and texture analysis. The selected formulation NG2 showed pseudoplastic behaviour which is important for easy extrudability from the tube and better spreadability during application of the formulation on wounds. These results were also confirmed by texture analysis. This optimized NG2 formulation was further evaluated for in-vivo wound healing activity in which a significant improvement was found in NG2 treated group of animals in comparison to SBT seed oil treated animals in terms of rate of wound contraction, hydroxyproline content, hexosamine content as well as in breaking and tensile strength of the wound. The epithelialization time was found to be less in NG2 treated rats in comparison to SBT seed oil. The ex-vivo studies performed by confocal laser microscopy showed more penetration of NG2 formulation into the skin in comparison to SBT seed oil. In terms of antibacterial and antifungal activity, NG2 formulation showed better activity in comparison to SBT seed oil. newlinexvi newlineConclusion: It may be concluded that the developed SBT seed oil nanoemulsion gel formulation could be easily applied and effectively healed both excision and incision types of wounds. The results indicated improved wound healing potential of nanoemulsion gel formulation in comparison to plain SBT seed oil. Key words: Hippophae rhamnoides L., nanoemulsion gel, sea buckthorn, spontaneous emulsification, wound healing. newline