Preparation and evaluation of darifenacin hydrobromide loaded nanostructured lipid carriers for oral administration

Abstract

Darifenacin hydrobromide is a selective M3 receptor antimuscarinic drug and it is used in the management of urinary frequency, urgency, and incontinence in detrusor instability. It is slightly soluble in water, undergoes extensive hepatic first-pass metabolism and has short elimination half-life (3-4 hours). Therefore, It has low bioavailability (15.4 % - 18.6 %). Darifenacin hydrobromide loaded nanostructured lipid carriers (NLCs) were formulated by emulsification sonication using different ratios of solid lipid to liquid lipid, different types and concentration of surfactants. Formula sixteen, containing darifenacin hydrobromide 8.9 mg, solid lipid glyceryl monostearate and olic acid in a ratio equal to 77.5:22.5, tween 80 (0.5%), and vitamin E that is added as an antioxidant, was considered as an opti-mized formula based on its particle size, polydispersity index (PDI), zeta potential and entrapment effi-ciency. This formula was subjected to further characterization such as DSC, FTIR, XRD, AFM, and release study. FTIR and DSC studies indicated no interaction between drug and excipients. XRD study showed a halo pattern which is a significant pattern of amorphous form of the drug. Atomic force mi-croscopy (AFM) study showed discrete lipid nanoparticles with no aggregation. Release study exhibited burst release in the first hour followed by sustained and controlled release up to 12 hours.