Development and validation of an LC-MS/MS method for the quantitative analysis of the adenosine A2a receptor antagonist NIR178 and its monohydroxy metabolite in human plasma: Application to clinical pharmacokinetics.

We report a selective LC-MS/MS method for the simultaneous quantitative determinations of the adenosine A2a receptor antagonist NIR178 (NIR178) and its major metabolite NJI765 in human plasma. Sample preparation steps involved protein precipitation, sample evaporation and reconstitution using a plasma sample volume of 0.1 ml plasma. Separation was achieved in 10 min on an Acquity UPLC BEH C18 1.7 µm, 2.1 × 50 mm column heated at 60°C with a gradient elution at 0.6 ml/min mobile phase made of water and acetonitrile both acidified with 0.1% formic acid. The detection was performed in positive ion mode and quantification based on multiple reaction monitoring. The linear response range was 1.00-1,000 ng/ml using a 1/x2 weighting factor. The intra- and inter-day accuracies (bias %) and intra- and inter-day precisions (CV, %) obtained for NIR178 and NJI765 were within the acceptance criteria. The normalized NIR178 and NJI765 matrix factor calculated from six lots of normal, lipemic and hemolyzed plasmas ranged from 0.97 to 1.05. The normalized recoveries of both NIR178 and NJI765 compared with their internal standards were consistent and reproducible with a CV ≤8.0. This method was successfully applied to support pharmacokinetic studies in adult patients with cancer.

Pharmacokinetic study of a new testosterone-in-adhesive matrix patch applied every 2 days to hypogonadal men.

The present study assessed pharmacokinetic testosterone time profile and dose proportionality after application of a new matrix testosterone patch (30, 45, and 60 cm2 containing 0.5mg of testosterone per cm2). This open study was a single dose, three-period, crossover trial with a randomised treatment sequence in 24 hypogonadal men, consisting in a single 48-h application of two patches of 2x 30 cm2, 2x 45 cm2, 2x 60 cm2, separated by a 5-day wash-out. Testosterone concentrations were determined during patch application and after patch removal. Dose proportionality was assessed on baseline corrected, dose normalised parameters for C av,corr/D, C max,corr/D and AUC(0-48),corr/D. Testosterone concentrations rose during the first 9h following patch application, remained relatively sustained until 48 h and then decreased abruptly after patch removal, with a half-life of 1.3h. Testosterone levels were maintained above 3 ng/mL for 42-45 h with all patches. C av were 3.39, 4.03 and 4.58 ng/mL and Cmax were 4.33, 5.29 and 6.18 ng/mL according to the doses. AUC 0-48), C av and Cmax were dose dependent with mean ratios within the acceptance range (0.70-1.43). In conclusion, dose linearity was demonstrated between the different strengths of testosterone patches. Application resulted in dose proportional increases in serum T levels in hypogonadal men into the low to mid-normal range within the first hours and achieved steady state for 48 h. During this short term study with three consecutive patch applications, this patch was shown to be efficient, convenient and safe with excellent adhesiveness and skin tolerability, and with no cross-contamination to partner or to environment.