Spectrofluorometric determination of alogliptin an antidiabetic drug in pure and tablet form using fluorescamine, a fluorogenic agent: application to content uniformity test

Alogliptin is an antidiabetic drug that belongs to a group called dipeptidyl peptidase-4 enzyme inhibitors. As the drug contains a primary amino group in its structure, it readily reacts with fluorescamine in slightly alkaline medium (borate buffer, pH 8.8) to form a highly fluorescent product. Emission of this product was measured at 477 nm (λ_ex = 387 nm). The linear range between the fluorescence intensity and the drug concentration was 0.1-0.5 μg ml^-1 with a good correlation coefficient (0.9986). Limits of detection and quantitation were 22 and 72 ng ml^-1 , respectively. Guidelines of the International Conference for Harmonisation were followed to validate the developed method with acceptable results. Alogliptin content was determined successfully in its commercial dosage form using the fluorescamine method with good recovery (98.60-101.26%). The method has excellent levels of accuracy and precision compared with the reported method as assessed using Student's t-test and Fisher's exact test. The method was applied successfully for the content uniformity test with high recovery and low relative standard deviation.

Simultaneous detection of 24 oral antidiabetic drugs and their metabolites in urine by liquid chromatography-tandem mass spectrometry

Drugs are the most frequent cause of hypoglycemia. Though the drug history is usually obvious in diabetic patients, the diagnosis could be a challenge in patients without a history of such exposure. Screening for oral antidiabetic drugs has been recommended as part of the hypoglycemia workup in patients without diabetes. Many published analytical methods of oral antidiabetic agents were usually of limited coverage and restricted to parent drugs only. In the current study, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) analytical system for the simultaneous detection of 24 oral antidiabetic drugs and their metabolites in urine was established and validated. The method covered both conventional as well as the newer antidiabetic drugs such as dipeptidyl peptidase-4 inhibitors and sodium-glucose cotransporter-2 inhibitors. Following sample preparation by solid phase extraction, analytes were detected by LC-MS/MS with multiple reaction monitoring triggered enhanced product ion scan. The method was successfully applied to 233 cases of unexplained hypoglycemia, with 83 oral antidiabetic drugs detected in 51 of the urine samples.

Enhanced LC-MS/MS analysis of alogliptin and pioglitazone in human plasma: Applied to a preliminary pharmacokinetic study

A new fast LC-MS/MS method was developed for determination of alogliptin and pioglitazone in human plasma. Linearity ranges of 10-400ngmL^-1 for alogliptin and 25-2000ngmL^-1 for pioglitazone, were found to be suitable for their bioanalysis covering the C_min and C_max values of the drugs. Direct precipitation technique was used for simultaneous extraction of the drugs successfully from human plasma samples. Chromatographic separation was achieved on a BEH C₁₈ column (50mm×2.1mm, 1.7μm) with 0.1% aqueous formic acid: acetonitrile (40:60, v/v) at a flow rate of 0.3mLmin^-1. The validated method was applied to a preliminary pharmacokinetic study on human volunteers. Monitoring the transition pairs of m/z 340.18 to 116.08 for alogliptin and m/z 356.99 to 133.92 for pioglitazone, using triple quadrupole mass spectrometer with multiple reaction monitoring, was achieved in the positive mode. The validated method is accurate and suitable for further clinical applications and possible bioequivalence studies.