ABSTRACT
Objective: To study the effects of betaxolol hydrochloride (BH) cationic liposomes on intraocular pressure (IOP), blood pressure ( BP) and heart rate ( HR) in rabbits to lay foundation for the development of new BH eye preparations. Methods:N-trimethyl chitosan (TMC60) was used as the coating material, the BH-loaded cationic liposomes (TMC60-BHL) were prepared. Total-ly 24 healthy rabbits were randomly divided into 4 groups using number method. Unilateral carotid artery intubation was carried out in the rabbits and connected a physiological recorder. TMC60-BHL, uncoated BHL, the marketed BH eye drops ( the positive control) and sterilized distilled water ( the negative control) with the volume of 50 μl was respectively used in one eye of the rabbits. IOP was detected by an ophthalmotonometer, and BP and HR were determined by the physiological recorder at the predetermined time intervals. Results:In the ipsilateral eyes, the maximum decrease in IOP for uncoated BHL and TMC60-BHL was 23. 00% and 26. 65%, respec-tively. In the contralateral eyes, the maximum decrease in IOP for uncoated BHL and TMC60-BHL was 18. 54% and 24. 33%, respec-tively. Compared with that of the positive control (19. 01%,15. 19%), the IOP decrease effect of uncoated BHL and TMC60-BHL was significant higher(P0. 05). Conclusion:TMC60-BHL shows significant IOP decrease effect without notable effect on BP and HR, which is valuable to be studied further.
ABSTRACT
The aim of this research is to develop thermo sensitive drug vehicles for glaucoma therapy in in-situ form to overcome the problems of poor bioavailability, naso lachrymal drainage and rapid precorneal elimination exhibited by conventional eye drops. Thermo sensitive ophthalmic drop was prepared using cold method by mixing thermo sensitive polymer pluronic F-127, viscosifying agent HPMC-E 50 LV and antiglaucoma drug (betaxolol hydrochloride). Prepared in situ gels were evaluated for physical parameters like appearance, gelation temperature, pH, drug content, rheological properties, isotonicity, sterility test, in vitro permeation and in-vivo ocular irritation study. The drug released from selected batch provides sustained release of betaxolol over 7 hours period and showed excellent ocular tolerance. The overall results of this study supports that the Pluronic/HPMC based vehicle could be used for controlled drug release that exhibits a greater potential for glaucoma therapy.