Effect of gold nanoparticles on timolol uptake and its release kinetics from contact lenses: In vitro and in vivo evaluation

Advances in chemistry and composition of soft materials for drug releasing contact lenses

“…One of the most recent work in this eld has been a study of the effect of gold nanoparticles (AuNPs) on the uptake and release of a drug, timolol from contact lens which is a potent non-selective beta blocker. 69 The release prole of the drug was analyzed under both in vitro and in vivo conditions. The main objective of this study was to nd novel treatment methodologies for glaucoma by the use of therapeutic contact lens.…”

“…They observed an insignicant increase in % swelling of the drug-laden contact lens compared to the blank contact lens. 69 This increase may be due to the effect of incorporated nanoparticle and drug on the crosslinking capacity of the fabricated lens. The dry weights of the blank contact lens (lens without soaking) and nanoparticles-drug soaked contact lens were measured and the swelling capacity measured using the formula…”

“…Optical transparency is measured by calculating the transmittance percentage using an UV spectrophotometer in the range of 200-800 nm. 69,71 Depending on the chemical nature of the drug, different methods are adapted to measure the amount of drug uptake by the lens. Solvent extraction and colorimetric analysis are two of the important methods to study drug uptake and release.…”

“…During the solvent extraction method, a solvent in which drug can be solubilized was used to extract the drug from the drugladen contact lens and the amount of drug present in the lens was estimated using the HPLC column. 69 The in vivo drug release study was carried out in rabbit models where the amount of drug released in the tear uid was calculated by LCMS studies. Draize technique scoring system was used to check the ocular tolerance of the drug-laden contact lens.…”

Novel Polyvinyl Pyrrolidone–Loaded Olopatadine HCl–Laden Doughnut Contact Lens to Treat Allergic Conjunctivitis

“…The in vitro flux studies of the SM-OL, DL-OL, and DNT-OL lenses were carried out by immersing the lens in the glass vial containing 2 mL of STF at 34 C 35 with constant stirring (100 RPM). 53 At the predetermined time intervals, 2 mL of STF was withdrawn from the vial and replaced with the same volume of fresh STF to maintain the prefect sink condition. The amount of olopatadine HCl and PVP released in the STF was quantified by HPLC 41,51 and colorimetric method, 52 respectively after suitable dilution [initial 2 time points were diluted (10 times) with media].…”