Background: Tadalafil is an oral drug that is used for treating erectile dysfunction (impotence)
and pulmonary arterial hypertension. It relaxes muscles and increases blood flow to particular
areas of the body. Objective: The present study was aimed to investigate the different pharmacokinetic
parameters of the two different formulations of Tadalafil (CAS no. 171596-29-5), one is conventional
tablet dosage formulation and other is ODS (Orally Disintegrating Strips) each of which contains 20
mg of tadalafil.
Materials and Methods: A simple, rapid bio-analytical LC-MS/MS method with appropriate sensitivity, selectivity, accuracy
and precision was developed and validated to quantify tadalafil in human plasma. Sildenafil was used as Internal
Standards (IS). Electrospray ionization (ESI) MS–MS was used to analyze tadalafil. A high proportion of organic solvent
Methanol: 10mM Ammonium Acetate in water (pH 6.38):: 9:1 (v/v) had been found best to coelute both substances with a
flow rate of 0.5 mL/min using Phenomenex Gemini C18 coloumn (4.6 mmx50 mm, 5 µm).
Results: The pharmacokinetic data of tadalafil in healthy human subjects of two different formulations show that the new
ODS (Orally Disintegrating Strips) formulation is bioequivalent with the conventional tablet dosage formulation. Both the
formulations were well tolerated with no observed adverse reactions.