In the present invention, we have prepared pH triggered in situ gel of Timolol Maleate for the glaucoma treatment. The carbopol 974 P in a range of 0.15 - 0.45 % w/v effectively formed gel at physiological pH 7.4 where as HPMC K 15 M responsible for effectively viscosity enhancement in the range of 0.25-0.75 % w/v. The developed Timolol Maleate in situ gel contains 0.125 % w/v Timolol Maleate which is l/4 th dose of marketed formulation. The developed in situ gel showed effectively diffused drug upto 8 h whereas ex vivo transcorneal permeation study showed 0.5 % w/w EDTA as an effective permeation enhancer in Timolol Maleate permeability. The histolpathological study confirmed safety and non irritant profile of developed in situ gel. Table 1 : Composition of developed formulation Different batches of Timolol Maleate in situ gel Name of (%w/v) excipients Fl F2 F3 F4 F5 F6 F7 F8 F9 Timolol Maleate 0.125 0.125 0.125 0.125 0.125 0.125 0.125 0.125 0.125 Sodium Chloride 0.80 0.80 0.80 0.80 0.80 0.80 0.80 0.80 0.80 Carbopol 974P 0.15 0.15 0.15 0.30 0.30 0.30 0.45 0.45 0.45 HPMCK15M 0.25 0.50 0.75 0.25 0.50 0.75 0.25 0.50 0.75 Benzalkonium 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 chloride Water q.s. 100 100 100 100 100 100 100 100 100
