ABSTRACT
Abstract Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used by the general population to alleviate inflammation and pain after oral surgeries. Piroxicam is among the most commonly used NSAIDs and excels in controlling pain, swelling, trismus and other common symptoms of inflammation. This study aimed to evaluate different concentrations of piroxicam and its major metabolite, 5'-hydroxypiroxicam, in human plasma samples over time using high performance liquid chromatography (HPLC) after liquid-liquid extraction. Briefly, 10 volunteers participated in this study after approval by the Ethics Committee of Bauru School of Dentistry, Universidade de São Paulo - USP, Brazil. Volunteers received a single dose oral of piroxicam (20 mg) and had blood collected at various times following an established protocol. The methodology of liquid-liquid extraction was effective for determining concentrations of piroxicam in plasma using HPLC in 10 out of 10 volunteers while 5'-hydroxypiroxicam was only detected in 2 out of 10 volunteers.
Subject(s)
Humans , Piroxicam/analogs & derivatives , Piroxicam/blood , Anti-Inflammatory Agents, Non-Steroidal/blood , Chromatography, High Pressure Liquid/methods , Liquid-Liquid Extraction/methods , Reference Values , Time Factors , Piroxicam/pharmacokinetics , Anti-Inflammatory Agents, Non-Steroidal/pharmacokinetics , Naproxen/blood , Naproxen/pharmacokinetics , Reproducibility of ResultsABSTRACT
In this study a rapid, simple and sensitive assay to quantify clozapine in human plasma by using reverse phase high performance liquid chromatographic method has been developed. Clozapine was extracted from human plasma using a mixture of chloroform: n-hexane 50:50 employing liquid- liquid extraction method. The calibration curve was found to be linear in the concentration range of 25-800 ng/ml. The inter day and intra day assay accuracy and precision fulfilled the criteria specified by USFDA, Guidance for industry: bioanalytical method validation. Clozapine was found to be stable in human plasma after 6 h incubation at room temperature, 50 days storage at -27[degree sign] C and freeze thaw cycles, as well as after reconstitution with mobile phase after 24 h of storage in refrigerator. The validated method offers the advantage of using minimum injection volume [25micro l] and plasma sample volume [300micro l]. The extraction method is simple and single step with no back extraction step, thus, making this method applicable to determination of pharmacokinetic profiles and parameters