Avanafil

Overview

Avanafil is a highly selective phosphodiesterase type 5 (PDE5) inhibitor primarily used for the treatment of erectile dysfunction (ED). Known for its rapid onset and excellent receptor selectivity, Avanafil offers a favorable safety profile and reduced off-target effects compared to earlier PDE5 inhibitors in its class.

Chemical & Physical Properties

• Purity: ≥ 99%

• Appearance: White crystalline solid

• Melting Point: 150–152 °C

• Solubility:

  • Freely soluble in DMSO

  • Slightly soluble in 0.1 M HCl

  • Practically insoluble in water

• LogP: Approx. 3.0

• pKa: ~2 and 5.2

Mechanism of Action

Avanafil selectively inhibits PDE5, blocking the degradation of cyclic guanosine monophosphate (cGMP) in smooth muscle cells. Increased cGMP levels promote vasodilation and enhanced blood flow in the corpus cavernosum, facilitating erection in the presence of sexual stimulation.

Pharmacological Profile

• Target: PDE5

• IC₅₀: ~5.2 nM (high potency)

• Selectivity: Strong selectivity versus PDE1, PDE6, and PDE11

• Onset of Action: ≈ 30–40 minutes

• Half-Life: Approx. 1–1.5 hours

• Elimination: Mainly excreted via bile and feces

Applications

• Pharmaceutical: Active pharmaceutical ingredient (API) used in oral ED formulations.

• Research: Used in pharmacology, cardiovascular studies, and signaling pathway research involving cGMP/PDE5.

Safety & Handling

• Classified as an irritant; avoid inhalation and contact with eyes or skin.

• Handle using standard laboratory protective equipment.

• Store in a cool, dry, and well-sealed container.

Storage Conditions

• Powder: Store at –20 °C, protected from moisture and light.

• Solution (in DMSO): Store at –80 °C for long-term stability; avoid repeated freeze-thaw cycles.

Key Advantages

• Very high PDE5 selectivity

• Faster onset than sildenafil or tadalafil

• Reduced incidence of vision-related side effects

• Suitable for rapid-acting ED formulations