Curcumin-loaded hydrotropic solid dispersion topical gel development and evaluation: A greener approach towards transdermal delivery of drugs

Curcumin's poor water solubility still presents a challenge. Because of Curcumin's instability in solubilizing solvents, using a non-sustainable solvent and dissolved oxygen in the Solution might be the problem. Thus, considering all facts, looking for a promising alternative solvent medium is in need. Indeed, a solution of hydrotropic agent has been assessed recently. Hydrotropic agents are the best replacements for organic solvents. These are eco-friendly, safe, and non-toxic agents. Hence, the presented research focuses on improving the solubility of Curcumin through a hydrotropic solid dispersion approach. Amazingly, Curcumin showed a significant solubility enhancement in sodium salicylate hydrotropic Solution. Sodium salicylate hydrotrope ensured the stability of Curcumin in Solution, maintained homogeneity, and exhibited antioxidant properties. Hydrotropy combined with the solid dispersion technique is a simple and effective way to improve the bioavailability of Curcumin. Hydrotropic solid dispersion loaded curcumin topical gel was developed to achieve transdermal delivery of Curcumin. Solid dispersion was prepared by solvent evaporation method and evaluated for in-vitro performance. In-vitro drug dissolution, drug content, FTIR, and XRD were carried out for the prepared HSD. The selected HSD (1:4) was loaded into a topical gel by dispersion method, and in-vitro parameters like drug content, Spreadability, pH, rate of drug dissolution, and drug content were performed. The solubility study has substantially enhanced the solubility of Curcumin in a 2M sodium salicylate hydrotropic solution. Sodium salicylate was compatible with formulating the solid dispersion. Hydrotropic solid dispersion was successfully prepared in 1:4 ratios. XRD results have shown the amorphous nature of Curcumin in the presence of sodium benzoate. The dissolution studies have shown improved release compared to pure Curcumin and PM (1:4). The prepared HSD was then incorporated into a gel by dispersion method using carbopol 934 and hydroxypropyl methylcellulose as a gelling agent. The Cur-HSD gel was homogeneous and transparent in appearance. The gel showed excellent Spreadability and drug content of 94.2 with 90.21% of percent drug release for 120 min and showed improved release in the presence of hydrotrope for improved topical delivery of Curcumin. Thus, to enhance the topical delivery of poorly soluble phytoconstituents, hydrotropes are suggested as a greener approach and to be applied for other poorly soluble phytoconstituents.