Several reports/patents/papers state that the pKas of POSACONAZOLE are 3.6 (piperazines) and 4.6 (triazoles), but I can't track down WHO measured these values. Based on reliable solubility-pH data, the values appear to be 1.20 and 3.57, with no signs of further ionization at least up to pH 8. It sure would be valuable if someone at Pion or at Univ. of Barcelona experimentally determined these values.