Effect of Oleic acid Incorporation on delivery of Carteolol from commercial Silicone contact lenses

Abstract

Carteolol HCl (CRT) is a non-selective beta blocker used to treat glaucoma. Currently, it is delivered via eye drop solutions, which suffer from many limitations (e.g. low bioavailability, high dose requirements and noncompliance). Contact lenses are used by scientists to control the release of ocular drugs, and they are considered as a promising therapeutic tool. This research aimed to evaluate the effect of oleic acid (OA) incorporation on CRT loading and its release from commercial silicone contact lens using the soaking method. Two different concentrations of oleic acid solution (35 and 60mg/ml) and one concentration of CRT solution (2 mg/ml) were used. Drug release profile and various lens properties including changes in visible light transmittance, water content, lens diameter and tensile modulus were investigated. The two used concentrations of oleic acid solution (35 and 60mg/ml) led to oleic acid loadings of 14.6% and 24% respectively, which in turn enhanced the total amount of released CRT by a factor of about 10 and 18, and increased the 90% drug release time by a factor of about 12 and 56, respectively for AIR OPTIX® lens. As for the characterization of prepared lenses, all the results were acceptable compared with unmodified lenses except for the change in diameter of lenses loaded with 24% of oleic acid. Our findings revealed the potential of using oleic acid to improve the uptake of CRT and to achieve sustained release kinetics without compromising the critical properties of contact lens.