Chromatography Forum

Does anyone have a recommendation of an HPLC method to separate promethazine and isopromethazine and other degradation product?

Try www.waters.com; click on "Library"; browse the "Waters Applications Notebook"; go to the compound index and select P for Promethazine.

You can try following method -

Column - Kromasil C18, 150 x 4.6 mm, 5 u
FR - 1.5 ml/min
250 nm

MP A - 2% Heptane sulphonate + 0.1% TEA, pH 7.5
MP B - ACN

Gradient - 70:30, hold for 10 min, change to 50:50 till 15 min, hold for 15 min.

Approx RT - Promethazine 21 min
Isopromethazine 27 min