Sildenafil citrate

Sildenafil citrate (CAS 171599-83-0), also marketed under the brand names Viagra and Revatio, is a phosphodiesterase type 5 (PDE5) inhibitor used as an active pharmaceutical ingredient in prescription drug manufacturing.

It is procured by pharmaceutical manufacturers and contract development organizations as a controlled API for finished dosage form production. The primary commercial application is in the manufacture of oral solid dosage forms.

These include tablets and film-coated tablets for erectile dysfunction treatment, where it functions as the active ingredient at defined therapeutic concentrations. Revatio-branded formulations target pulmonary arterial hypertension.

This represents a distinct regulatory and manufacturing pathway that requires separate product specifications. Generic drug manufacturers across regulated markets source the material as a bulk API to produce bioequivalent products.

These products are measured against established reference listed drugs. Contract manufacturers also use it in suspension formulations for pediatric pulmonary hypertension indications to meet specific patient needs.

The material is supplied as a white to off-white crystalline powder in bulk quantities suited to pharmaceutical-scale production. It is available to USP and EP (Ph. Eur.) grade specifications.

These are the standard requirements for regulated market submissions. Sourcing typically requires compliance documentation including CoA, DMF references, and GMP certification from the manufacturing site.