Both assays were linear over the calibration range of 0.781 to 200 渭g/ml.
Considering the method of extraction from plasma, mean intra and inter-day accuracy was 鈭?.18% and 鈭?.79%, respectively. Mean intra and inter-day precision was 7.91% and 9.22%, respectively.
Regarding the extraction method from DPS, mean intra and inter-day accuracy was 2.21% and 2.41%, respectively. Mean intra and inter-day precision was 8.01% and 9.19%, respectively. Daptomycin in DPS was found to be stable for 7 days at room temperature (20-25 掳C) and for at least 30 days at 4 掳C. A statistically significant (p < 0.001) linear correlation was found between daptomycin extracted from plasma and from DPS (r2 = 0.919). DPS represents a safe and cheap strategy to store and ship plasma samples. Thus, it is suited for pharmacokinetic studies and therapeutic drug monitoring of daptomycin in hospitals without a therapeutic drug monitoring laboratory.