Bioequivalence of saxagliptin/metformin immediate release (IR) fixed-dose combination tablets and single-component saxagliptin and metformin IR tablets in healthy adult subjects.

BACKGROUND: As compared with individual tablets, saxagliptin/metformin immediate release (IR) fixed-dose combination (FDC) tablets offer the potential for increased convenience, compliance, and adherence for patients requiring combination therapy. OBJECTIVES: Two bioequivalence studies assessed the fed-state and the fasted-state bioequivalence of saxagliptin/metformin IR 2.5 mg/500 mg FDC (study 1) and saxagliptin/metformin IR 2.5 mg/1,000 mg FDC (study 2) relative to the same dosage strengths of the individual component tablets [saxagliptin (Onglyza™) and metformin IR (Glucophage(®))] administered concurrently. STUDY DESIGNS: These were randomized, open-label, single-dose, four-period, four-treatment, crossover studies in healthy subjects (n = 24 in each study). The treatments in study 1 were a saxagliptin/metformin IR 2.5 mg/500 mg FDC tablet in the fed and fasted states on separate occasions, and saxagliptin 2.5 mg and metformin IR 500 mg tablets co-administered in the fed state and fasted states on separate occasions. The treatments in study 2 were a saxagliptin/metformin IR 2.5 mg/1,000 mg FDC tablet in the fed and fasted states on separate occasions, and saxagliptin 2.5 mg and metformin IR 1,000 mg co-administered in the fed state and fasted states on separate occasions. The pharmacokinetics, safety, and tolerability of each treatment were evaluated. RESULTS: For both studies, saxagliptin and metformin in the FDCs were bioequivalent to the individual components in both the fed and the fasted states as the limits of the 90 % confidence interval of the ratio of adjusted geometric means for all key pharmacokinetic parameters were contained within the predefined 0.800 to 1.250 bioequivalence criteria. Co-administration of saxagliptin and metformin IR was generally safe and well tolerated as the FDCs or as individual tablets. CONCLUSIONS: Saxagliptin/metformin IR 2.5 mg/500 mg and saxagliptin/metformin IR 2.5 mg/1,000 mg FDCs were bioequivalent to individual tablets of saxagliptin and metformin of the same strengths in both the fed and the fasted states. No unexpected safety findings were observed with saxagliptin/metformin IR administration. The tolerability of the FDC of saxagliptin/metformin IR was comparable to that of the co-administered individual components. These results indicate that the safety and efficacy profile of co-administration of saxagliptin and metformin can be extended to the saxagliptin/metformin IR FDC tablets.

Simultaneous oral therapeutic and intravenous ¹4C-microdoses to determine the absolute oral bioavailability of saxagliptin and dapagliflozin.

AIM: To determine the absolute oral bioavailability (F(p.o.) ) of saxagliptin and dapagliflozin using simultaneous intravenous ¹4C-microdose/therapeutic oral dosing (i.v.micro + oraltherap). METHODS: The F(p.o.) values of saxagliptin and dapagliflozin were determined in healthy subjects (n = 7 and 8, respectively) following the concomitant administration of single i.v. micro doses with unlabelled oraltherap doses. Accelerator mass spectrometry and liquid chromatography-tandem mass spectrometry were used to quantify the labelled and unlabelled drug, respectively. RESULTS: The geometric mean point estimates (90% confidence interval) F(p.o) . values for saxagliptin and dapagliflozin were 50% (48, 53%) and 78% (73, 83%), respectively. The i.v.micro had similar pharmacokinetics to oraltherap. CONCLUSIONS: Simultaneous i.v.micro + oraltherap dosing is a valuable tool to assess human absolute bioavailability.

Overcoming bioanalytical challenges in an Onglyza(®) intravenous [(14)C]microdose absolute bioavailability study with accelerator MS.

BACKGROUND: An absolute bioavailability study that utilized an intravenous [(14)C]microdose was conducted for saxagliptin (Onglyza(®)), a marketed drug product for the treatment of Type 2 diabetes mellitus. Concentrations of [(14)C]saxagliptin were determined by accelerator MS (AMS) after protein precipitation, chromatographic separation by UPLC and analyte fraction collection. A series of investigative experiments were conducted to maximize the release of the drug from high-affinity receptors and nonspecific adsorption, and to determine a suitable quantitation range. RESULTS: A technique-appropriate validation demonstrated the accuracy, precision, specificity, stability and recovery of the AMS methodology across the concentration range of 0.025 to 15.0 dpm/ml (disintegration per minute per milliliter), the equivalent of 1.91-1144 pg/ml. Based on the study sample analysis, the mean absolute bioavailability of saxagliptin was 50% in the eight subjects with a CV of 6.6%. Incurred sample reanalysis data fell well within acceptable limits. CONCLUSION: This study demonstrated that the optimized sample pretreatment and chromatographic separation procedures were critical for the successful implementation of an UPLC plus AMS method for [(14)C]saxagliptin. The use of multiple-point standards are useful, particularly during method development and validation, to evaluate and correct for concentration-dependent recovery, if observed, and to monitor and control process loss and operational variations.