SPL Set ID: 16323b0e-78ae-40e5-be93-04f698dd672b

Timolol maleate USP is a non-selective beta-adrenergic receptor blocking agent. Its chemical name is (-)-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° 405 nm in 1.0N HCl (C = 5%) = -12.2° (-11.7° to -12.5°) 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 has a molecular weight of 432.50. It is a white, odorless, crystalline powder which is soluble in water, methanol, and alcohol. Timolol maleate is stable at room temperature. Timolol maleate ophthalmic solution is supplied in two formulations: timolol maleate ophthalmic solution, which contains the preservative benzalkonium chloride; and timolol maleate ophthalmic solution, the preservative-free formulation. Preservative-free timolol maleate ophthalmic solution, USP is supplied in a single-dose vial, as a sterile, isotonic, buffered, aqueous solution of timolol maleate in two dosage strengths: Each mL of preservative-free timolol maleate ophthalmic solution USP 0.25% contains 2.5 mg of timolol (3.4 mg of timolol maleate). The pH of the solution is approximately 7.0, and the osmolarity is 252-328 mOsm. Each mL of Preservative-free timolol maleate ophthalmic solution USP 0.5% contains 5 mg of timolol (6.8 mg of timolol maleate). Inactive ingredients: monobasic and dibasic sodium phosphate, sodium hydroxide to adjust pH, and water for injection. formula