Photophysical Properties, Solubility and Stability of Curcumin in Surfactant Media: The Role of the Surfactant’s Head Group

Abstract

The yellow-orange color pigment found in the Indian spice plant turmeric is composed primarily of curcumin, a natural poly phenolic molecule1. It has attracted a lot of attention due to its widespread biological and pharmacological properties. Despite its extensive spectrum of physiological and therapeutic effects, curcumin's poor water solubility and lack of bioavailability are the two most significant obstacles to its usage as a potential medicine. Furthermore, the lack of stability of curcumin in an aqueous media complicates its utilization1. As a result, researchers are concentrating their efforts on encapsulating curcumin in variety of carriers, including micelles, reverse micelles, mixed micelles, liposomes, suspensions, hydrogels, and emulsions2. Surfactant-based delivery methods have gotten a lot of interest since they help in faster and more efficient drug absorption3. The properties of surfactants are governed by the chain length of the hydrophobic tail and the charge on the hydrophilic headgroup4. The goal of the present study is to find out how curcumin interacts with four distinct conventional surfactants that have the same hydrophobic chain length but different head groups e.g. anionic, cationic and zwitterionic. The role of the charge on the head group of the surfactants in influencing the photophysics, solubility, and stability of curcumin under various physiological conditions was examined using UV-Visible and fluorescence spectroscopic techniques. The solubility and stability of curcumin exhibited strong dependence on the nature of the surfactant. The effect of surfactant on the antioxidant capability of curcumin has also been studied in the presence of the surfactants.