Preparation and In-Vitro Characterization of Diclofenac Sodium Niosomes for Ocular Use

Drugs are commonly applied to the eye for a localized action on the surface or in the interior of the eye. A major problem in ocular therapeutics is the attainment of an optimal drug concentration at the site of action. Poor bioavailability of drugs from diclofenac sodium ocular dosage form is mainly due to the precorneal loss factors which include tear dynamics, non-productive absorption, transient residence time in the cul-de-sac, and the relative impermeability of the corneal epithelial membrane. Niosomes have been reported as a possible approach to improve the low corneal penetration and bioavailability characteristics shown by conventional ophthalmic vesicles. In the present study, the nonionic surfactant vesicles were prepared by lipid film hydration method using span 60 and cholesterol with various molar ratios and characterized for entrapment efficiency, in-vitro drug release study, surface charge, rheological character and physical stability. The span 60: cholesterol in molar ratio of 100:60 showed higher entrapment of drug and released 77.34% ± 1.04 at 10th h. Study may be concluded that the non-ionic surfactant vesicles formulated with span 60: cholesterol in a molar ratio of 100:60 showed potential approach to improve the ocular bioavailability of diclofenac sodium for the prolonged period of time.