Studies On The Mechanism Of Sodium Hyaluronate As Vehicles Of Ophthalmic Drugs

Hyaluronic acid (HA) is a linear glycosaminoglycan composed of alternating disaccharide unit containing N-acetylglucosamine and glucuronic acid, found in extracellular matrix of most animals. Its sodium salt, sodium hyaluronate (SH), is usually used in clinic. As drug vehicle, SH has been used in many preparations, especially in eye drops. Not only has SH had good biocompatibility, but also it can obviously prolong residence time in administration area, improve drug bioavailability, diminish adverse drug reaction. In this paper, three drugs with different characteristics were chloramphenicol, ciprofloxacin hydrochloride and ibuprofen. The influence of SH as vehicle on these drugs' release and absorption were studied, as well as its interaction with drugs. We expect to provide a theoretical basis for SH as ophthalmic drug vehicles.1 The main research contents(1) Influence of SH as vehicle on drug release in vitroThe penetration rates of drugs were determined with modified Franz diffusion cell in solutions with different influence factors. The influence factors included viscosity of solution, concentration of drug, concentration of SH and SH of different relative molecular mass (M_r).(2) Influence of SH on percutaneous absorption of drugsThe penetration rates of 0.25% chloramphenicol, 0.3% ciprofloxacin hydrochloride and 0.1 % ibuprofen through excised mouse skin were determined with modified Franz diffusion cell in aqueous solutions with and without 1% SH. The penetration rates of SH in these solutions were also determined by radioimmunoassay.(3) Interaction between SH and drugsUV spectroscopy, differential scanning calorimeter (DSC), infrared spectroscopy...