SPL Set ID: 2d5dcaa5-97ee-40c3-aa29-fcfb91fb78e1

Dorzolamide hydrochloride and timolol maleate ophthalmic solution, USP is the combination of a topical carbonic anhydrase inhibitor and a topical beta-adrenergic receptor blocking agent. Dorzolamide hydrochloride USP is described chemically as: (4 S-trans )-4-(ethylamino)-5,6-dihydro-6-methyl-4 H -thieno[2,3- b ]thiopyran-2-sulfonamide 7,7-dioxide monohydrochloride. Dorzolamide hydrochloride is optically active. The specific rotation is: [α] 25°C (C=1, water) = ~ -17°. 405 nm Its molecular formula is C 10 H 16 N 2 O 4 S 3 •HCl and its structural formula is: Dorzolamide hydrochloride USP has a molecular weight of 360.91. It is a white to off-white, crystalline powder, which is soluble in water and slightly soluble in methanol and ethanol. Timolol maleate USP is described chemically as: (-)-1-( tert -butylamino)-3- [(4-morpholino-1,2,5-thiadiazol-3-yl)oxy]-2-propanol maleate (1:1) (salt). Timolol maleate possesses an asymmetric carbon atom in its structure and is provided as the levo-isomer. The optical rotation of timolol maleate is: [α] 25°C in 1N HCl (C=5) = -12.2° (-11.7° to -12.5°). 405 nm Its molecular formula is C 13 H 24 N 4 O 3 S•C 4 H 4 O 4 and its structural formula is: Timolol maleate USP has a molecular weight of 432.50. It is a white to practically white powder which is soluble in water, methanol, and alcohol. Timolol maleate is stable at room temperature. Dorzolamide hydrochloride and timolol maleate ophthalmic solution, USP is supplied as a sterile, clear, colorless to nearly colorless, isotonic, buffered, slightly viscous, aqueous solution. The pH of the solution is approximately 5.65, and the osmolarity is 242 to 323 mOsM. Each mL of Dorzolamide hydrochloride and timolol maleate ophthalmic solution, USP contains 20 mg dorzolamide (equivalent to 22.26 mg of dorzolamide hydrochloride USP) and 5 mg timolol (equivalent to 6.83 mg timolol maleate USP). Inactive ingredients are sodium citrate, hydroxyethyl cellulose, sodium hydroxide, mannitol, and water for injection. Benzalkonium chloride 0.0075% is added as a preservative. Chemical Structure of Dorzolamide Chemical Structure of Timolol maleate