Formulation and evaluation of Metformin Hydrochloride-loaded Curcumin–Lycopene Niosomes

Curcumin and lycopene, both are naturally occurring potent antioxidants which can be used in the treatment of oxidative stress. The biological sources to obtain curcumin and lycopene are curcuma longa and Solanum lycopersicum, respectively. The aim of this research study is to develop curcumin–lycopene conjugate-based biguanide niosomes. Span 60 as non-ionic surfactant and cholesterol as a stabilizer were used for the preparation of metformin hydrochloride-loaded niosomes by the ethanol injection method. This research dealt with the composition, formulation, evaluation and optimization of niosomes. The particle size and polydispersity index were found to be in the range from 139.6 to 509 and 0.152 to 0.541 nm, respectively. The entrapment efficiency and drug loading capacity were observed in the range of 40.43–79.02 and 26.954 to 78.17%, respectively. The in vitro drug release studies showed the sustained release of drug in all formulations up to the period of 24 h. Kinetic analysis of in vitro drug release studies showed that when the ratio of Span 60 and cholesterol is 1:1.5 and 1:2, the formulations followed first-order kinetics. When the ratio changed to 1:1, the formulation followed the Korsmeyer–Peppas model and finally at the ratio of 1.5:1 and 2:1, formulations followed the Higuchi kinetics and Hixson–Crowell kinetics, respectively. Formulation S2 is concluded as an optimized formulation on the basis of all evaluation parameters.