In the present invention, we have disclosed thermosensitive sol-gel transition system of Dorzolamide hydrochloride for glaucoma treatment. The developed sol- gel transition system effectively formed gel at physiological temperature 37� C. with sustained appearance upto 8 hours after instillation in cul de sac. The developed formulation contains 0.5 % Dorzolamide Hydrochloride as effective to minimise intra ocular pressure although it is % th dose of marketed formulation. The thermosensitive property of developed formulation is due to poloxamer 407 polymer in the range of 16-20 % w/v where as sustained release property is due to viscosity enhancer polymer HPMC K 15 M in the range of 0.5 - 1% w/v. We evaluated 0.01 % v/v benzalkonium chloride as effective preservative in developed formulation. Optimized formulation successfully sustained release of drug upto 5 hours in ex vivo goat corneal permeability study. Comparative in vivo study in normotensive rabbits showed that optimized formulation sustained therapeutic effect upto 8 hours. Table 1 : The composition of developed thermosensitive sol - gel phase transition system Dorzolamide Poloxamer 407 HPMC K15M Benzalkoniumm chloride Sodium Chloride Puri. Water Hydrochloride (%w/v) (%w/v) (%w/v) (%v/v) (%w/v) q.s.(ml) Fl 0.5 16 0.5 0.01 0.5 10 F2 0.5 16 0.75 0.01 0.5 10 F3 0.5 16 1.0 0.01 0.5 10 F4 0.5 18 0.5 0.01 0.5 10 F5 0.5 18 0.75 0.01 0.5 10 F6 0.5 18 1.0 0.01 0.5 10 F7 0.5 20 0.5 0.01 0.5 10 F8 0.5 20 0.75 0.01 0.5 10 F9 0.5 20 1.0 0.01 0.5 10
