Drug Information for Trandate (Prometheus Laboratories Inc.): DESCRIPTION

TRANDATE Injection is an adrenergic receptor blocking agent that has both selective alpha1-adrenergic and nonselective beta-adrenergic receptor blocking actions in a single substance.

Labetalol hydrochloride (HCl) is a racemate chemically designated as 2-hydroxy-5-[1-hydroxy-2-[(1-methyl-3-phenylpropyl) amino]ethyl]benzamide monohydrochloride, and it has the following structure:

Labetalol HCl has the empirical formula C₁₉H₂₄N₂O₃•HCl and a molecular weight of 364.9. It has two asymmetric centers and therefore exists as a molecular complex of two diastereoisomeric pairs. Dilevalol, the R,R' stereoisomer, makes up 25% of racemic labetalol.

Labetalol HCl is a white or off-white crystalline powder, soluble in water. TRANDATE Injection is a clear, colorless to light yellow, aqueous, sterile, isotonic solution for intravenous (IV) injection. It has a pH range of 3 to 4. Each milliliter contains 5 mg of labetalol HCl, 45 mg of anhydrous dextrose, 0.1 mg of edetate disodium; 0.8 mg of methylparaben and 0.1 mg of propylparaben as preservatives; and citric acid anhydrous and sodium hydroxide, as necessary, to bring the solution into the pH range.