Glaucoma

The objectives of this study were to maximize; a) the in vitro transcorneal release, b) the IOP-lowering effect and, c) the duration of action, of Latanoprost acid (LAT) ophthalmic gels. The in vitro transcorneal release of LAT from a 1st set of gel formulations that containing different concentrations of Azone™ (as enhancer) with fixed concentration of C-974® (as mucoadhesive) were studied. Formulation that showed greatest permeability parameters at lowest Azone™ concentration was selected for preparation of a 2nd set of ocular gels containing various C-974® concentrations. The in vitro transcorneal release was assessed, and the best C-974® concentration required for preparation of formulations that can be conceded as ideal ophthalmic LAT gels hve been pinpointed and scaled up for in vivo IOP-lowering efficacy study using TONO-PEN™ AVIA tonometer in rabbits for 4-consecutive days.  Various test formulations have showed significant but varied augmentations in both, in vitro and in vivo results. Formulations (GAZ-4) & GC-4 have shown the highest therapeutic IOP lowering effects; i.e., (7.8±1.8), (6.5±2.1), respectively. Particularly noteworthy with both formulations the IOP base-line didn’t re-established after 24 hours, and their durations of action in the single-dose study were 47±2.25, and 48±1.5, respectively. The in vitro release, onset, magnitude & duration of action of action of LAT gels have been enhanced and extended for up to 2-day with two gel formulations.  Nonetheless, the success in developing a novel ophthalmic formulation depended for great extent upon the crucial net outcomes of a very sensitive interplay/balance between the drug and additives.

  Beta-blockers are the first line drugs in lowering the elevated and normal intraocular pressure associated with neuropathy of glaucoma, but for many reasons the use of this group of drugs requires supportive medications. The systemic side effects due to overdose of these drugs leads to pathetic complications in patients suffering with cardiac and pulmonary diseases. This article provides necessary information for the safe use of beta-blockers with detailed information about the disease glaucoma. Recent advances in the glaucoma therapy with beta-blockers and novel drug delivery systems developed are reviewed in this study.   Key words: Glaucoma, beta-blockers, intraocular pressure, Timolol, Levobunolol