edex® (alprostadil for injection) is a sterile, pyrogen-free powder containing alprostadil in an alfadex (α-cyclodextrin) inclusion complex. Alprostadil is an endogenous substance known as prostaglandin E₁ (PGE₁ ). edex® (alprostadil for injection) is supplied in single-dose, dual-chamber cartridges.

edex® (alprostadil for injection) is lyophilized in single-dose, dual-chamber cartridges intended for use with the reusable edex (alprostadil for injection) ® injection device. One chamber of the cartridge contains alprostadil, alfadex and lactose as a sterile, pyrogen-free powder. The other chamber contains 1.075 mL of sterile 0.9% sodium chloride. The edex® (alprostadil for injection) cartridges are supplied in three strengths: 10 mcg cartridge (10.75 mcg alprostadil, 347.55 mcg α-cyclodextrin, 51.06 mg lactose); 20 mcg cartridge (21.5 mcg alprostadil, 695.2 mcg α-cyclodextrin, 51.06 mg lactose); 40 mcg cartridge (43.0 mcg alprostadil, 1,390.3 mcg α-cyclodextrin, 51.06 mg lactose). The edex® (alprostadil for injection) injection device is used to reconstitute the sterile powder in one chamber with the sterile 0.9% sodium chloride in the other chamber. After reconstitution, the edex® (alprostadil for injection) injection device is used to administer the intracavernous injection of alprostadil.

The chemical name for alprostadil is (1R,2R,3R)-3-Hydroxy-2-[(E)-(3S)-3-hydroxy-1-octenyl]-5-oxocyclopentane heptanoic acid. The empirical formula is C₂₀ H₃₄ O₅ and the molecular weight is 354.49. The chemical structure is:

The α-cyclodextrin inclusion complex improves the water solubility of alprostadil. The empirical formula of α-cyclodextrin is C₃₆ H₆₀ O₃₀ and the molecular weight is 972.85.

The chemical structure is:

Alprostadil alfadex is a white, odorless, hygroscopic powder. It is freely soluble in water and practically insoluble in ethanol, ethyl acetate and ether. After reconstitution, the active ingredient, alprostadil, immediately dissociates from the α-cyclodextrin inclusion complex. The reconstituted solution is clear and colorless and has a pH between 4.0 and 8.0. When the single-dose, dual-chamber cartridge containing either 10.75, 21.5 or 43.0 mcg of alprostadil is placed into the edex® (alprostadil for injection) injection device and reconstituted, the deliverable amount of alprostadil in each milliliter is 10, 20 or 40 micrograms, respectively.

Last reviewed on RxList: 12/9/2008
This monograph has been modified to include the generic and brand name in many instances.