A validated stability indicating DAD–HPLC method for determination of pentoxifylline in presence of its pharmacopeial related substances

A validated, simple and sensitive stability-indicating HPLC method was introduced for the analysis of Pentoxifylline in the presence of its pharmacopeial related substances, Caffeine anhydrous and Theophylline anhydrous, in the presence of its forced degradation products. This was achieved using a gradient DAD–HPLC method in order to achieve a good separation between the related substance peaks, complying with the pharmacopeial requirement, and an adequate retention time for the Pentoxifylline peak. The method was validated according to the ICH guidelines and different HPLC parameters were optimized for the determination of Pentoxifylline in its dosage form (sustained release tablets). Furthermore, the study of forced degradation of Pentoxifylline was done under various conditions including; hydrolysis (acid, alkaline and neutral), oxidation, dry heat and photo-decomposition. The proposed method could separate Pentoxifylline peak from those of the different forced degradation product peaks and the purity of the Pentoxifylline peak was confirmed using the photo-diode array detector.