Claims for Patent: 6,316,443

Summary for Patent: 6,316,443

Title:	Ophthalmic compositions comprising combinations of a carbonic anhydrase inhibitor and a β-adrenergic antagonist
Abstract:	Combinations of a β-adrenergic antagonist and a topical carbonic anhydrase inhibitor are particularly useful in the treatment of ocular hypertension, especially in patients insufficiently responsive to treatment with β-adrenergic antagonists.
Inventor(s):	John J. Baldwin
Assignee:	Merck and Co Inc
Application Number:	US09/532,704
Patent Claims:	1. An ophthalmic formulation for treatment of ocular hypertension in a subject whose intraocular pressure is inadequately controlled by β-adrenergic antagonists comprising an ophthalmologically acceptable carrier, 0.5 to 5% (w/w) of a carbonic anhydrase inhibitor of the structure: the individual diastereomers, the individual enantiomers or mixtures thereof, or an ophthalmologically acceptable salt thereof, wherein: A is carbon or nitrogen; Z is NHR or —OR; R is C1-6 alkyl, either straight or branched chain; R1 is (a) hydrogen (b) C1-3 alkyl, or (c) C1-4 alkoxy-C1-4 alkyl; and X is —SO2— or —C(O)—; and 0.01 to 1.0% of a β-adrenergic antagonist selected from betaxolol, bufenolol, carteolol, levobunolol, metipranolol, and timolol, or an ophthalmologically acceptable salt thereof. 2. The formulation of claim 1 wherein A is carbon, Z is —NHR, and X is —SO2—. 3. The formulation of claim 2 wherein: R is a) —CH2CH3; b) —CH2CH2CH3; or c) —CH2CH(CH3)2, R1 is a) hydrogen; b) —CH3; c) —CH2CH2CH3; or d) —CH2CH2CH2OCH3. 4. The formulation of claim 3 wherein b-adrenergic antagonist is timolol or an ophthalmologically acceptable salt thereof. 5. The formulation of claim 1 wherein b-adrenergic antagonist is betaxolol or an ophthalmologically acceptable salt thereof. 6. The formulation of claim 3 wherein R is —CH2CH3; and R1 is —CH3; or R is —CH2CH2CH3; and R1 is —CH2CH2CH2OCH3; or R is —CH2CH3; and R1 is —CH2CH2CH3; or R is —CH2CH(CH3)2, and R1 is hydrogen. 7. The formulation of claim 1 wherein the concentration of carbonic anhydrase inhibitor is 0.7 to 2.0%. 8. The formulation of claim 1 further comprising 0.1% to 2% of a gum. 9. The formulation of claim 8 wherein the gum is gellan gum. 10. A method of treating ocular hypertension which comprises the topical ocular administration, to a patient in need thereof an effective amount of an ophthalmic formulation comprising an ophthalmologically acceptable carrier, 0.5 to 5% (w/w) of a carbonic anhydrase inhibitor of the structure: the individual diastereomers, the individual enantiomers or mixtures thereof, or an ophthalmologically acceptable salt thereof, wherein: A is carbon or nitrogen; Z is NHR or —OR; R is C1-6 alkyl, either straight or branched chain; R1 is (a) hydrogen (b) C1-3 alkyl, or (c) C1-4 alkoxy-C1-4 alkyl; and X is —SO2— or —C(O)—; and 0.01 to 1.0% of a β-adrenergic antagonist selected from betaxolol, bufenolol, carteolol, levobunolol, metipranolol, and timolol, or an ophthalmologically acceptable salt thereof. 11. The method according to claim 10 which comprises the topical ocular administration of an effective amount of an ophthalmic formulation to a patient in need thereof wherein: the β-adrenergic antagonist is timolol, betaxolol or an ophthalmologically acceptable salt thereof and R is a) —CH2CH3; b) —CH2CH2CH3; or c) —CH2CH(CH3)2; and R1 is a) hydrogen; b) —CH3; c) —CH2CH2CH3; or d) —CH2CH2OCH3. 12. The method according to claim 10 wherein: A is carbon; Z is NHR; X is —SO2—; R is a) —CH2CH3; b) —CH2CH2CH3; or c) —CH2CH(CH3)2; and R1 is a) hydrogen; b) —CH3; c) —CH2CH2CH3; or d) —CH2CH2OCH3. 13. The method according to claim 11 wherein the β-adrenergic antagonist is timolol or an ophthalmologically acceptable salt thereof. 14. The method according to claim 12 wherein R is —CH2CH3 and R1 is —CH3; or R is —CH2CH2CH3 and R1 is —CH2CH2CH2OCH3. 15. A topical ophthalmic formulation for treatment of ocular hypertension in a patient in need thereof comprising an ophthalmologically acceptable carrier, 0.5 to 5% (w/w) of a carbonic anhydrase inhibitor of the structure: the individual diastereomers, the individual enantiomers or mixtures thereof, or an ophthalmologically acceptable salt thereof, wherein: A is carbon; Z is NHR; R is C1-6 alkyl, either straight or branched chain; R1 is C1-3 alkyl, and X is —SO2—; and 0.01 to 1.0% of timolol, betaxolol or an ophthalmologically acceptable salt thereof, wherein the ratio of carbonic anhydrase inhibitor to β-adrenergic antagonists is greater than one. 16. The formulation of claim 15 wherein R is —CH2CH3 and R1 is —CH3. 17. The formulation of claim 15 further comprising from about 0.1 to about 2% gellan gum.