Bioequivalence of potassium chloride products is determined by giving subjects a single 80 milliequivalent dose and, finally, to determine the baseline, we take urine samples during two days before the dose is given.
This schematic summarizes the study design for the potassium chloride bioequivalence studies. The basic design is a two-period, two-sequence, two-treatment crossover with each study period 8 days in duration. The controlled potassium diet is given throughout the study. The diet is given for 4 days. Then on study days 5 to 6, urine is collected at various intervals throughout the day. Dosing takes place on the morning of day 7 and then urine is collected again at various intervals throughout days 7 and 8. The urine collection intervals on days 5 and 6, the baseline days, match the urine collection intervals on days 7 and 8, the post-dosing days.
I mentioned that we collect urine to measure potassium excretion in these bioequivalence studies. As has been discussed earlier today, most of the time in our bioequivalence studies, we measure drug concentrations in plasma, serum, or blood because this is the most sensitive and accurate way to determine bioequivalence. However, in