Active encapsulation of diclofenac sodium into liposomes for ophthalmic preparations

Abstract

Liposomes as a drug carrier in the pharmaceutical industry has gained currency since its discovery in 1965 by Bangham A. D. Liposomes have been shown to improve bioavailability as they can be delivered to target sites and possess sustained release properties which could be used to mitigate certain weaknesses associated with current diclofenac sodium eye drops. Diclofenac sodium (DNa) eye drop is a sterile Nonsteroidal Anti-inflammatory Drug (NSAID) with diclofenac sodium as its active ingredient. It is indicated for the lessening of ocular pain, prevention of miosis in eye operations, easing of postoperative inflammation and cystoids macular edema. The residence time of eye drops after application has been found to be 1-2 minutes as a result of continuous production of tears diluting the active ingredient, draining the eye drops into the nasolacrimal path, and eliminating it during blinking. As a result of the active ingredient not residing at the target site for the required duration, more frequent administration and medication is required and the risk of non-compliance is increased. Given the aforementioned potential of liposomes to redress the above weaknesses of current eye drops (dosage form) available for diclofenac sodium ophthalmic application, this study sought to encapsulate diclofenac sodium into liposomes for ophthalmic application. The main components of liposomes (cholesterol and phosphotidylcholine) and incubation time were set as the independent variables while percentage encapsulation, polydispersity index (PDI) and drug release profile constituted the dependent variable. Using analysis of variance (ANOVA) and t-test statistics, the interaction between the independent variables and their effect on the dependent variables were tested.