Transdermal delivery of diclofenac using various nano-drug delivery vehicles

Abstract

Abstract Diclofenac (2-[(2,6-dichlorophenyl)amino]phenyl]acetic acid) was incorporated into different drug delivery vehicles to investigate the transdermal delivery thereof. These drug delivery vehicles included nano-emulsions, nano-emulgels and a colloidal suspension containing drug-loaded nanoparticles. The formulation of nano-emulsions and nano-emulgels was at different concentrations of evening primrose oil (EPO). The different drug delivery vehicles were compared in terms of the type of drug delivery vehicle and the concentration of EPO within the vehicle (if included).The characterization of the drug delivery vehicles and membrane release studies determined if the active pharmaceutical ingredient (API) was successfully released from the vehicle. Following this, in vitro skin diffusion studies and tape stripping (topical delivery) were conducted to establish whether the drug delivery vehicles assisted the API to successfully penetrate the skin and reach the target-site (transdermal delivery). By performing methyl thiazolyl tetrazolium (MTT) and neutral red (NR) assays on human keratinocyte (HaCaT) cells, the cytotoxicity of the drug delivery vehicles was investigated.Results from the membrane release and in vitro skin diffusion studies showed that the nano-emulsions and the 10% EPO drug delivery vehicles increased API release and diffusion when compared to the other drug delivery vehicles. However, the colloidal suspension had the highest concentrations of API within the stratum corneum-epidermis and the epidermis-dermis. The drug delivery vehicles showed minimal cytotoxic effects at concentrations equivalent to that which had permeated through the skin.