Journal of Chemical Metrology Articles
Articles In Press
Journal of Chemical Metrology
Articles In Press
1) Development of ledipasvir and sofosbuvir pure certified reference materials for improving quality of pharmaceutical analysis
The pure materials play a pivotal role in controlling the quality of pharmaceutical products, ensuring comparability and metrological traceability of test results, and performance evaluation of measuring instruments. Herein, the purity characterization of chronic hepatitis C virus sofosbuvir and ledipasvir pharmaceuticals was established based on the assessment of mass fractions of potential impurities in the material including heavy metals, residual solvents, and water content, as well as structurally-related organic impurities. The combined estimate of these impurities by mass balance approach led to indirect purity determination of sofosbuvir and ledipasvir materials. The impurities mass fractions in each material were assigned by validated chromatographic methods, Karl Fisher titrator, and inductively coupled plasma-based method. The certified purity values of sofosbuvir and ledipasvir and their corresponding expanded uncertainties (k =2.0 at 95% CL) were found (99.79±0.03) %, (99.69±0.04) %, respectively. The developed certified reference materials (CRMs) with small uncertainty values will support pharmaceutical testing laboratories in their efforts to maintain and improve the quality of results and provide them with high-order CRMs for the accurate determination of both analytes in raw materials and finished productsDOI http://doi.org/10.25135/jcm.73.2210.2591 Keywords Ledipasvir sofosbuvir value assignment mass balance approach certified reference materials Available online: December 01, 2022 DETAILS DOWNLOAD PDF © ACG Publications. All rights reserved.
2) Validated chromatographic methods for concurrent determination of atorvastatin and perindopril
Two simple, selective, precise, and accurate chromatographic methods, namely reversed-phase high-performance liquid chromatography (RP-HPLC) method and High-performance thin-layer chromatography (HPTLC), were developed and validated for the simultaneous determination of Atorvastatin (ATO) and Perindopril (PER). The developed HPTLC method was used for the separation and quantitation of the studied drugs on silica gel 60F254 TLC plates. Dichloromethane: Methanol: Ethyl acetate: Glacial acetic acid (6:2:2:0.1, v/v/v/v) was used as a developing system and the separated bands were UV-scanned at 221 nm. Linear relationships were obtained in the range of 800 – 4800 ng/band for Atorvastatin and 200 – 1200 ng/band for Perindopril with a regression coefficient greater than 0.999. The Rf value of the drug was found to be 0.70 ± 0.02 and 0.39 ± 0.03 for Atorvastatin and Perindopril respectively. The developed RP-HPLC depended on chromatographic separation of the studied drugs on a C18 column using Acetonitrile: Methanol: Potassium dihydrogen orthophosphate (pH 3 adjusted with orthophosphoric acid) ((40:10:50), v/v/v) as a mobile phase delivered at a constant flow rate of 1 mL/min with UV detection at 240 nm. The calibration curves were linear (r2 > 0.999) over the concentration range 20-100 µg/mL for Atorvastatin and 10-50µg/mL for Perindopril. The average retention times for Atorvastatin and Perindopril were 3.42 and 8.92 min, respectively. Factors affecting the developed methods have been studied and optimized. Further, methods validation has been carried out according to ICH guidelines. The proposed methods were successfully applied for the determination of the studied drug simultaneously in bulk and synthetic mixture qualitatively and quantitatively. Statistical analysis by the F test showed no significant difference between the results obtained by the two methods. The uncertainty measurement was also carried out for the quantification of both components. The proposed HPTLC method proved to be more sensitive, while the HPLC gave more reproducible results and was time-saving.DOI http://doi.org/10.25135/jcm.72.2208.2545 Keywords Atorvastatin perindopril HPLC Method HPTLC Method statistical comparison Method Validation Available online: October 16, 2022 DETAILS DOWNLOAD PDF © ACG Publications. All rights reserved.