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Objective: To assess the comparative bioavailability of two formulations (40 mg delayed-released [DR] tablet; test and reference) of pantoprazole (CAS 102625-70-7) in healthy volunteers of both sexes, with and without food., Methods: The study was conducted using an open, randomized, two-period crossover design with a 1-week washout interval, in two groups, with and without food. Plasma samples were obtained for up to 24 h post dose. Plasma pantoprazole concentrations were analyzed by liquid chromatography coupled to tandem mass spectrometry (LC-MS-MS) with positive ion electrospray ionization using multiple reactions monitoring (MRM). From the pantoprazole plasma concentration vs. time curves, the pharmacokinetic parameters AUC(last) and C(max) were obtained, with and without food., Results: The limit of quantification was 5 ng/mL for plasma pantoprazole analysis. The geometric mean and 90% confidence interval CI of test/reference percent ratios were, without and with food, respectively: 104.6540% (90.8616%-120.5401%) and 99.9708% (90.9987%-109.8275%) for C(max), 95.6634% (85.2675%-107.3267%) and 89.3500% (83.6630%-95.4237%) for AUC(last)., Conclusion: Since the 90% CI for AUC(last) and C(max) ratios were within the 80-125% interval proposed by the US FDA, it was concluded that pantoprazole 40 mg DR tablet (test formulation) with and without food was bioequivalent to the reference 40 mg DR tablet for both the rate and extent of absorption.

The fragmentation of dihydropyridine calcium-channel antagonists are compared by electrospray ionization (ESI) and atmospheric pressure photonization (APPI). The results demonstrate that in ESI the preferred ionization process is in positive mode, with the mass spectra of [M+H]+ showing base peak ions probably formed by loss of alcohols from carboxyl groups. Conversely, in APPI, a high intense peak is observed in negative mode due to deprotonated molecule [M-H]- after two serial 1, 2-hydride shifts leading to a rearranged deprotonated molecule [M-H]-. These ions undergo another 1,2-hydride shifts to produce a nitro-phenyl product ion of m/z 122. The APPI is also used to develop a method for the quantitation of dihydropyridines (e.g., nifedipine) in human plasma.

Objective: The aim was to assess the comparative bioavailability of two formulations (200 mg tablet) of amiodarone (CAS 19774-82-4) in healthy volunteers of both sexes, with and without food., Methods: The study was conducted using an open, randomized, two-period crossover design with a 3-week washout interval, in two groups, with and without food. Plasma samples were obtained for up to 240 h post dose. Plasma amiodarone concentrations were analyzed by liquid chromatography coupled to tandem mass spectrometry (LC-MS-MS) with positive ion electrospray ionization using multiple reactions monitoring (MRM). From the amiodarone plasma concentration vs. time curves, the following pharmacokinetic parameters were obtained, with and without food: AUC(last), AUC(inf), AUC(0-240h), AUC(0-72h) and C(max)., Results: The limit of quantification was 1 ng/mL for plasma amiodarone analysis. The geometric mean and 90% confidence interval CI of Test/Reference percent ratios were, without and with food, respectively: 107.61 (92.73-124.89) and 100.6 (94.1-107.5) for C(max), 107.05 (95.88-119.51) and 100.2 (96.0-104.7) for AUC(last), 107.27 (95.78-120.15) and 100.8 (97.0-104.8) for AUC(0-72h), 106.76 (95.84-118.94) and 100.2 (96.0-104.7) for AUC(0-240h) and AUC(inf) 105.15 (94.18-117.41) and 100.7 (96.6-105.0)., Conclusion: Since the 90% CI for AUC(0-72) and C(max) ratios were within the 80-125% interval proposed by the US FDA, it was concluded that the amiodarone 200 mg tablet (test formulation) with and without food was bioequivalent to the reference 200 mg tablet for both the rate and extent of absorption.