Physicochemical investigation of encapsulation of antihypertensive drug captopril in mixed micellar system to enhance its delivery

This research work provides insight into the solubilization of a non-ionic drug captopril (CAP) in the micellar media of cationic surfactant cetyltrimethylammonium bromide (CTAB) and mixed micellar media of two nonionic surfactants Tween-80 and Triton X-100. CAP-surfactant interactions were analyzed by simple and differential absorption spectroscopy as well as by conductometry and the efficiency of the selected micellar system was assessed by calculating the values of partition coefficient (Kx), the free energy of partition (Delta GP), binding constant (Kb) and the free energy of binding (Delta Gb). Results from differential spectroscopy depicted a noteworthy increase in the solubilization of CAP with the addition of nonionic surfactants (Tween-80 and TX100) in the micellar solution of CTAB. Furthermore, conductometric response of micellar media has been used to calculate the degree of dissociation (beta), the free energy of micellization (Delta Gm) thermodynamic parameters of micellization.