Validated RP – HPLC Method for Simultaneous Estimation of Tadalafil and Dapoxetine in Combined Pharmaceutical Dosage Forms

Aim: To develop a new, simple, fast, rapid, accurate, efficient and reproducible RP-HPLC method for the simultaneous estimation of Tadalafil and Dapoxetine.

Background: Estimation of Tadalafil and Dapoxetine is a combination drug of choice used to treat preamature ejaculation in men.

Objective: The main objective of the Simultaneous estimation of combined drug is to establish identity, physical characteristics and potency of the drugs and to demonstrate the suitability of the assay method to provide useful data to ensure the technique gives satisfactory and consistent results.

Materials and methods: A HPLC (Inertsil, Water2695) with UV/VIS Detector/PDA detector, UV (lab India, UV 3000⁺ series) and Inertsil C18 250mm × 4.6mm × 5µm column was used. A new method was established for simultaneous estimation of Dapoxetine   and Tadalafil by RP-HPLC method.  The chromatographic conditions were successfully developed for the separation of Dapoxetine   and Tadalafil by using inertsil C18 5µm (4.6*250mm) column, flow rate was 1ml/min, mobile phase ratio was Phosphate buffer (0.05M) pH 3: MEOH (30:70%v/v) (pH   was   adjusted   with   orthophosphoric   acid), detection wave length was 260nm.

Results: The results were in good agreement with those obtained with official HPLC with absorption maximum of 260 nm by preparing mobile phase 70:30 methanol: phosphate buffer with flow rate 1 ml/min and it run for 30 minutes by selecting column Inertsil C18 4.6mm×250 mm. All the results obtained with good precise, accurate and robustness as per international conference on Harmonization (ICH) guidelines.

Conclusion: It can be concluded that the proposed RP-HPLC method is accurate, precise, sensitive, robust and reproducible for the simultaneous analysis of Tadalafil and  Dapoxetine    with less tailing factor and is also economical.Inertsil C18 column (4.6×250mm)5µ, flow rate was 1ml/min. Both samples scan in the range of 200 to 400 nm and maximum wavelength was identified at 260 nm.