Stability indicating HPLC and spectrophotometric methods for the determination of bupropion hydrochloride in the presence of its alkaline degradates and related impurity

MSn, LC‐MS‐TOF and LC‐PDA studies for identification of new degradation impurities of bupropion

“…It revealed that conjugation between carbonyl and 3‐chlorophenyl groups was disrupted in V similarly to in III . This UV data suggested that impurity V may be the same as the benzylalcohol derivative 3 , which is reported to form from 1 (O'Byrne et al ., ) and is also reported to be an alkali degradant (Abbas et al ., ). Compound V was found to undergo mass fragmentation (Fig.…”

“…() and Abbas et al . (), seven degradation impurities ( I–VII ) were formed in 0.1 m NaOH at 85°C over 8 h eluting at relative retention times (RR T ) of 0.42, 0.49, 0.67, 1.20, 1.53, 2.72, and 3.44, respectively (Fig. b).…”

“…Hence, based on these results, the drug was found to be susceptible only to the alkaline medium as also reported by the earlier studies. Owing to the results of our study being different from the earlier reports (Abbas et al ., ; O'Byrne et al ., ), a degradation kinetics study was carried out in 0.1 m NaOH in order to understand the degradation behavior of the drug (Table ). It revealed that the level of I increased gradually up to 12 h and decreased thereafter.…”

“…Recently, Abbas et al . () have identified three known impurities in the drug substance on the basis of limited quadrupole LC‐MS data. However, a critical analysis of chemical structure of bupropion reveals that the drug may undergo various chemical changes under different chemical environments, leading to the formation of many degradation impurities.…”

Stability-indicating liquid chromatographic and UV spectrophotometric methods for the quantification of ciprofibrate in capsules and tablets

“…Owing to specificity/selectivity limitations (e.g., in general terms, the degradation products present functional groups that absorb at the same wavelength of the intact drug), there are very few reports on the use of UV spectrophotometry for stability assays. However, there are some reports involving derivative spectroscopy that have been published recently (Abbas et al, 2012;Cielecka-Piontek, Lunzer, Jelińska, 2011). LC methods have taken precedence over conventional analysis methods; reverse-phase LC coupled with ionic suppression probably accounts for over 85% of stability-indicating methodologies for low-molecularweight pharmaceutical entities.…”