Effect of Spironolactone on the Micellar Properties of Non-Ionic Surfactant: Assessment by Conductivity and Surface Tension Methods

Abstract

An interaction of spironolactone (SPI) with octyl phenol ethoxylate (Triton-X-100 or TX-100) has been investigated by using conductometric and tensiometric measurement. The value of critical micellar concentration (CMC), degree of ionization (a) and thermodynamic parameters like standard enthalpy of micellization (?H°m), standard entropy of micellization (?S°m) and standard Gibb’s free energy (?G°m) were determined by conductivity data. The negative value of ?G°m shows spontaneity in the solubilization of drug. Various interfacial parameters such as maximum surface excess concentration (Gmax) and minimum area per molecule (Amin) was determined by surface tension measurement. All these parameters have been discussed in terms of drug-surfactant interactions. Based on the result it was found that variation in the presence of spironolactone in micellar properties of TX-100 increases with increase in concentration of drug. This study will help the pharmaceutical industries in the discovery of new drug and enhancement of their bioavailability.