Methazolamide Liposome Eye Drops

Carbonic anhydrase inhibitors (CAIs) were first used to lower intraocular pressure (IOP) in glaucoma in 1954, with the introduction of acetazolamide, methazolamide and diclofenamide were subsequently. Although IOP can be controlled by oral administration of CAIs, systemic side effects severely limit this mode of therapy. Methazolamide liposome eye drops were studied to solve this problem.The UV analysis method of methazolamide was studied and proved to be accurate and reliable for quantitative analysis in vitro through methodology investigation. The encapsulation efficiency (EE%) determination method of methazolamide liposome was created by sephadex column chromatography. It was proved to be accurate and reliable for the detection of encapsulation efficiency of methazolamide liposome through the plot of elution curve and the investigation of elution characteristic.Calcium acetate gradient method was taken as the basic manufacture of methazolamide liposome by comparative selection of different liposome preparationmethod. Proceeded with the calcium acetate gradient method, the concentration of calcium acetate, the phosphatidylcholine cholesterol ratio, drug lipid ratio and temperature were conducted for influential factor investigation, after that the methazolamide liposome with highest EE% (>80%) was obtained. Furthermore, by studying the correlation between stirring rate and particle size, the methazolamide liposome with finest particle size was gained, with mean PCS particle size of 182.2±31.1 nm.In order to realize the releasing behavior of methazolamide liposome, its determination method in vitro was created. Effect of topically administered methazolamide liposomes on the change in IOP in NZW rabbits revealed the maximum IOP reduction reached a value of -10.18±4.96mmHg after 4 hours of topical administration methazolamide liposomes and the IOP reduction was sustained during the time of the experiment (8 hours). Comparing the results of both 1% brinzolamide and methazolamide liposomal formulations, it is obvious that methazolamide liposomes produced a more significant lowering in IOP compared with 1% brinzolamide and showed a more sustained action of IOP reduction. Results of HPLC analysis indicated that the methazolamide liposome eye drops can transfer the corneal barrier and penetrate into the anterior humor. The results demonstrated that this preparation was superior to topical administration.