Bioanalyses
The biological sample analysis test will be blinded, where the administered formulation is not known for each cycle during the sample analysis. Appropriate sample pretreatment methods were established based on drug properties, and a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was used to determine the blood concentration of nifedipine. The internal standard method (internal standard nifedipine d6) was used for quantification and the sample pretreatment method as protein precipitation.