Abstract
The objective of this study was to evaluate the diffusivity and the release characteristics of different antiemetics from plurionic gels using various in vitro models (polymeric membrane, skin sheds of Yellow Rat and Com Snake). Dexamethasone, haloperidol, lorazepam, and metoclopramide were used as model drugs in the PLO gel. An accurate, simple and sensitive method using a Cl8 Luna column was developed and validated for the analysis of the aforementioned antiemetics in the solution as well as in gel formulation. The in vitro release of these drugs from the PLO gels over a period of 15 hours were 18.33±12.60%, 21.60±2.11%, 89.36±9.85%, 99.02±8.16%, respectively. The percentage of drug diffused from methanolic solution over 24 hours through skin sheds of Yellow Rat Snake were 4.15±0.46%, 1.05 ±0.6%, 0.4±0.04%, 0.35±0.3% for dexamethasone, haloperidol, lorazepam and metoclopramide respectively. It was evident from all the four drug studies, the highly aqueous soluble drug, metoclopramide, had the highest in vitro release and the lowest diffusion through the skin sheds. Dexamethasone showed a significant increase in the diffusion through skin sheds of Yellow Rat Snake compared to Com Snake. This was attributed to the differences in the lipid content, surface morphology and the thickness of the snake skin sheds. The use of limonene as a penetration enhancer with the co-solvent propylene glycol and solvent extraction of the snake skin sheds enhanced the diffusion of both dexamethasone and lorazepam. Hence the incorporation of limonene along with propylene glycol can be used to enhance the absorption of the antiemetic medications from the topical gel formulation in vivo.