Akademik Veri Yönetim Sistemi
Acta Pharmaceutica, cilt.47, sa.1, ss.21-30, 1997 (SCI-Expanded)
Hydrogel drug delivery systems have been investigated with regard to their suitability for ophthalmic application. The in vitro release of lidocaine hydrochloride from ophthalmic gels containing polyacrylic acid polymers (Carbopol 934, 940 and 941) was investigated. Linearization of the data was attempted according to the zero-order, first-order and diffusion kinetics. The data obtained were in good accordance with Q √t mechanism. Physico-chemical properties of the preparations including pH, surface tension and viscosity were measured after neutralization and sterilization. The viscosity significantly decreased by adding lidocaine hydrochloride to derivatives of Carbopol vehicles. The results showed that there were no significant differences between different Carbopol derivatives of the same concentration in relation to percentage of the released drug and time. However, in the formulations that contain increasing amounts of the same polymeric carrier, the amount of released active ingredient decreased with time. This indicates that the observed decrease depends on the polymer concentration and the drug-polymer interaction. Increase of the polymer viscosity effects the release rate constant and the quantity of the drug released from the preparation.