Background: Acefylline (Acef) is a derivative of theophylline that has bronchodilator effects.
Two binary mixtures were marketed for Acef: Acefylline piperazine/ Phenobarbitone (Acef-
P/Phen) and Acefylline heptaminol/ Cinnarizine (Acef-H/ Cinn). To our knowledge, none of the reported
methods had the capacity to determine Acef in its binary mixture in the presence of its degradation
products and potential impurity theophylline (Theo).
Methods: Two validated RP-LC methods were established for the determination of Acef-P/Phen and
Acef-H/ Cinn, in the presence of Acef degradation products and its’ potential impurity Theo. A complete
study of the forced acidic, alkaline, and oxidative degradation of Acef was presented. The methods
were based on LC separation on RP C18 columns using isocratic and gradient elution for Acef-P
/Phen and Acef-H /Cinn mixtures, respectively. Different chromatographic conditions were examined
Results: Linear responses were attained over concentration ranges of 75-500/15-1000 μg/mL and 100-
1000 /50-500 μg/mL with mean percentage recoveries of (100.72±1.23)%/ (99.29±1.12)% and
(100.44±1.27)%/ (99.01±0.97)% for Acef-P/Phen and Acef-H /Cinn, respectively. ICH guidelines were
used for methods validation and all the parameters were found to be acceptable.
Conclusion: The methods showed to be accurate, precise, and specific for the analysis of Acef-P/Phen
and Acef-H /Cinn in drug substance, drug product, and in laboratory prepared mixtures in the presence
of Theo and up to 50% of degradation products. The structures of the main degradation products and
the expected degradation pathway were suggested using the MS data.