Formulation and evaluation of thymoquinone niosomes: application of developed and validated RP-HPLC method in delivery system.

A rapid, accurate, and sensitive reverse phase high-performance liquid chromatographic (RP-HPLC) method was developed and validated for the estimation of Thymoquinone (TMQ) in API as well as in noisome. The chromatograms were developed with the mobile phase - water: 2-propanol: methanol (50:45:5 //) as a solvent system at 254 nm. The method was validated as per ICH guidelines for different parameters and the recovery of TMQ was calculated in developed niosomes. Further, TMQ loaded niosomes (TMQNIOS) were prepared and evaluated for different parameters. The optimized TMQNIOS (F3) was further evaluated for surface morphology, drug release, permeation study, and confocal laser scanning microscopic (CLSM) study. The method showed linearity range between 6.25 and 100 µg/ml with low detection limit and quantitation limit with a value of 2.08 and 6.25 µg/ml. The developed formulations showed the vesicle size and encapsulation efficiency in the range of 157.32 ± 3.15 to 211.44 ± 5.23 nm and 59.32 ± 4.87 to 83.21 ± 3.55%, respectively. The drug release result showed the significant higher release from TMQNIOS in compared to TMQDIS, and the release kinetics data showed Higuchi's equation with highest regression coefficient values. The permeation study and the confocal laser microscopy study further confirmed the enhancement in permeation of TMQ in the intestinal mucosa.