Development of an Aloe vera-based Emulgel for the Topical Delivery of Desoximetasone

Objectives: Desoximetasone (DMS) is a widely recommended drug for the topical treatment of plaque psoriasis. However, low water solubility and short half life of DMS present major obstacles in the development of an effective topical formulation. Thus, there is a demand for the development of a safe and effective topical system to deliver hydrophobic DMS. The present study aimed to develop an Aloe vera-based emulgel formulation to ensure enhanced skin deposition of DMS for effective treatment of plaque psoriasis. Materials and Methods: Different formulations (DE1-DE4) of Aloe vera emulgel were prepared using dispersion technique, wherein varying concentrations of propylene glycol (6-14% w/w) and carbopol 934 (0.5-1.0% w/w) were used. Results: Zetasizer measurements revealed that the globule size of the formulations ranged from 10.34 mu m +/- 0.9 to 14.60 mu m +/- 1.4 (n=50). Extrudability analysis for the DE3 and DE2 formulations revealed an extrudability of 5.6 +/- 0.11 g/cm(2) and 5.8 +/- 0.13 g/cm(2), respectively. The pH of the formulations was recorded in the range of 5.8-6.8. Among these formulations, DE3 showed a maximum drug content of 94.64%+/- 0.29 (n=3), and thus was used for further in vitro evalutions. A texture analyzer showed that an optimized DE3 formulation was firmer and exhibited optimal spreadability in comparison with the DE2 formulation. For DE3, the mean max force that represented "firmness" was recorded to be 833.37 g, where as the mean area, denoting "work of shear", was 324.230 g.sec. The DE3 formulation exhibited DMS permeation of 95.40 +/- 1.6% over a period of 7 h, as detrmined using an in house fabricated Franze diffusion cell. Evaluation of in vitro release kinetics revealed that the release of DMS fitted into the Korsmeyer-Peppas model. Conclusion: Physicochemical characteristics and enhanced in vitro permeation of DMS from Aloe vera emulgel highlight its suitability to be efficiently employed for the topical treatment of skin ailments.