Objective: The aim of this study was to develop and validate two HPLC methods for the quantification of meloxicam and tenoxicam from transdermal therapeutic systems.
Methods: Based on 1.0% hydroxypropyl methylcellulose 15000, transdermal patches containing meloxicam or tenoxicam were prepared by solvent evaporation technique. Analytical performances of the HPLC methods for the quantification of meloxicam and tenoxicam from such systems were assessed in terms of specificity, linearity, detection limit, quantification limit, recovery and precision.
Results and discussion: The linearity of the method was assessed through a calibration curve in the 1.0 – 75.0 μg∙mL-¹ concentration range, with a regression coefficient higher than 0.999. The detection limit and the quantification limit were found to be 0.46 μg∙mL-¹ and 1.39 μg∙mL-¹, for meloxicam; and 0.88 μg∙mL-¹, respectively 2.64 μg∙mL-¹ for tenoxicam. According to the European Pharmacopeia 5.0 the mean recovery was found to be between 75% and 125%. As performance criteria for precision was used the RSD% which were lower than 2.0% for both methods.
Conclusions: The proposed liquid chromatography methods provide selective, linear and precise results for the quantification of meloxicam and tenoxicam from transdermal therapeutic systems. The presence of a single peak in the chromatograms of the analyzed transdermal patches with meloxicam or tenoxicam, certify the successful determination of the active pharmaceutical ingredient in the prepared patches.
Tag Archives: high performance liquid chromatography
The Monitoring of Immunosuppressive Therapy with Tacrolimus in Patients with Kidney Transplant, Based on the Pharmacokinetic Criteria
Background: Therapeutic drug monitoring (TDM) in patients with Chronic Kidney Disease (CKD) with kidney transplant, represents a major post transplant concern due to the characteristics of this special category of patients, particularities which can generate changes of the pharmacokinetic profile of the administered medication.
Material and methods: The current study is a retrospective pharmacokinetic study, over a period of 50 months, including a group of 36 kidney transplanted patients with CKD. Tacrolimus blood concentration was determined by a validated high-performance liquid chromatography method (HPLC), at a 12 hour time interval from the last administration of the immunosuppressive medication and before the following dose (Residual concentration, Cmin(trough)).
Results: During the monitoring of therapy, based on the pharmacokinetic criteria, 252 measurements of blood concentration were determined, 58 of these being outside the therapeutic window.
Conclusions: The results obtained show that it is mandatory to continue to monitor closely medical therapy based on the pharmacokinetic criteria in view of improving drug administration. The other ways of monitoring therapy: the clinical and biochemical criteria should not be overlooked. In addition, the interindividual variability of patients should be considered, as well as drug interaction which can alter the pharmacokinetics of tacrolimus.