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This article presents the development of a reversed-phase (RP) high-performance liquid chromatographic (HPLC) method for determination of process-related impurities in a celecoxib drug substance following Analytical Quality by Design (AQbD) principles. The method from European Pharmacopeia (EP) for celecoxib drug substance does not sufficiently separate celecoxib from its EP impurity B because the system suitability criterion is not achieved (resolution NLT 1.8). The same issue was observed with the proposed method from United States Pharmacopeia (USP) for celecoxib capsules, where EP impurity A elutes under the main peak. A new HPLC method was developed that eliminates the disadvantages of the two pharmacopeial methods and is capable of efficiently separating and determining all seven impurities listed in EP and the proposed USP monographs. The development of a new HPLC method started with method scouting, in which various C18 and phenyl stationary phases were tested. Improved selectivity was obtained only with a chiral stationary phase. An immobilized Chiralpak IA-3 column used in RP mode turned out to be the most appropriate for method optimization. The ratio of acetonitrile in the mobile phase, flow rate, and column temperature were recognized as critical method parameters (CMPs) and were further investigated using a central composite face response-surface design. A multiple linear regression (MLR) method was applied to fit the mathematical models on the experimental data to determine factor–response relationships. The models created show adequate fit and good prediction abilities. The Monte Carlo simulation method was used to establish the design space. The method developed was verified in terms of precision, sensitivity, accuracy, and linearity, and the results showed that the new method is suitable for determination of seven process-related impurities of celecoxib.

A novel, rapid, selective, precise and accurate stability-indicating reversed phase high-performance liquid chromatography (RP-HPLC) method was developed for Pterostilbene. The method was validated accord¬ing the Q2(R1) guidelines of International Conference on Harmonization (ICH) with respect to system suitability, linearity, range, LOD, LOQ, accuracy, precision. The forced degradation was validated according to International Conference on Harmonization (ICH). The chromatographic analysis was performed on Agilent 1260 Infinity HPLC instrument using an ACE C-18 Column (150 x 4.6mm, 3um) and mobile phase comprising water: ACN (35:65 v/v) at the flow rate of 1 ml/min. The column eluent was monitored at 306nm. The total run time was 6 min and the average retention time of Pterostilbene was found to be 3.19 min. The method showed excellent linear response with correlation coefficient values (R2) of 0.999 which were within the limit of correlation coefficient (R2 >0.995). Average percentage recovery of Pterostilbene was 98.65 found within acceptable limits (97.0-103%). The LOD and LOQ were 0.006875ng and 0.020626 ng respectively. Percent RSD values of intra-day precision study were below 2%. Pterostilbene showed significant degradation when exposed to water, acid (0.1N HCL), base (0.1N NaOH), oxidizing agent (10% H2O2), and UV light. Pterostilbene content of the aqueous extract (extractive yield: 5.25%) of Pterocarpus marsupium powder by using proposed HPLC method was found to be 1.732µg. Similarly, for aqueous-ethanolic extract (extractive yield: 10%) was found to be 30.540µg. Ninety five % ethanolic extract (extractive yield: 3.33%) was found to contain 34.663µg Pterostilbene.

Memantine, a non-competitive NMDA receptor antagonist, is used to treat Alzheimer’s disease. Therefore, loading memantine in nanoparticles (NPs) could be an essential tool to improve the treatment effectiveness while reducing drug toxicity. Even though some approaches have been described to quantify memantine, none reported optimized methods using high-performance liquid chromatography resorting to ultraviolet detection (UV–HPLC) to determine encapsulation in NPs. The present research developed a HPLC method using pre-column derivatization for quantitatively analyzing memantine hydrochloride in NPs. Memantine was derivatized using 9-fluorenylmethyl chloroformate (FMOC). The developed method was fully validated regarding suitability, specificity, linearity, sensitivity, precision, accuracy, and robustness according to the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use guidelines. The retention time of memantine was 11.393 ± 0.003 min, with a mean recovery of 92.9 ± 3.7%. The new chromatographic method was validated and found to respond linearly over 5–140 μg/mL, with a high coefficient of determination. Intraday precision lay between 3.6% and 4.6%, and interday precision between 4.2% and 9.3%. The stability of memantine was also tested at 4 °C and −20 °C, and no signs of decay were found for up to 6 months. The new method was properly validated and proved simple, sensitive, specific, accurate, and precise for determining memantine encapsulation efficiency in lipid NPs. Greenness was evaluated, presenting a final score of 0.45. In the future, this methodology could also be applied to quantify memantine in different nanoformulations.

[...]this approach can be appropriate for the resolution and quantification of genotoxic impurities in selpercatinib and can also be applicable for the evaluation of stress degradation products. Existing literature indicates a lack of reported analytical methods for quantifying genotoxic impurities in selpercatinib, and no author has characterized the stress degradation compounds of selpercatinib. [...]this paper introduces an optimized HPLC method for quantifying genotoxic impurities of selpercatinib and LC-MS/MS characterization of degradation products (DPs). Method Validation The guidelines prescribed by ICH (ICH 1994; ICH 1996; ICH 2003) and authors reported in literature were utilized for conducting validation study of the proposed method (Varma et al., 2022; Rajesh et al., 2022; Varma et al., 2023; & Rajesh et al., 2023). The method sensitivity for detecting the targeted impurities underwent rigorous assessment employing the signal-to-noise (S/N) ratio procedure.

The accurate, fast, cost effective RP- HPLC chromatographic method was developed and validated as per the ICH guidelines, for linearity, accuracy, interday-intraday precision, specificity and selectivity, robustness, solution stability. Current study is focused on the method development of dasatinib (DS) which is having anticancer activity by inhibiting tyrosine kinase enzyme. Standard curve of DS was constructed in methanol at λmax 325 nm using UV spectroscope. For RP-HPLC method development mobile phase used was acetonitrile: Potassium dihydrogen phosphate buffer in the ratio 60:40 %v/v, with flow rate of 1 mL/min at a temperature of 30 ℃. Maximum wavelength 325 nm were selected for the analysis of DS. The linearity of the solution was detected at 325 nm within the concentration range from 20 -120 µg/mL with a correlation value (R2) of 0.999975 indicating a very strong relationship between dependent and independent variables suggesting the accuracy of the method selected. The concentration of DS in niosomes was determined by the currently developed method. Validation parameters were used to evaluate, specificity, linearity, sensitivity, accuracy, precision, and ruggedness. About 98-102 (%v/v) of DS was found to be within standard limits and compliant with the standards set by the International Council of Harmonization (ICH) demonstrating the accuracy of the method used. The RP-HPLC method is more sensitive, accurate and precise compared to the previously reported method. There was no interference of excipients in the recovery study. The low value of %RSD was suggested that the developed method is sensitive. The proposed reverse phase high performance liquid chromatographic method proved to be convenient, simple and effective for the quality control of DS.

In this study, the establishment and validation of a stable reversed‐phase high‐performance liquid chromatography (RP‐HPLC) method for the concomitant estimation of the two drugs in dosage forms are presented. Method optimization was achieved by response surface methodology (RSM) using Design Expert Software 13, taking into account the special physicochemical characteristics of metoclopramide (MET) (a moderately polar molecule, pKa 9.5) and camylofin (CAM) (a less polar, hydrophobic molecule, pKa 8.7). Chromatographic resolution was achieved on a phenyl‐hexyl column under isocratic mobile phase mode in which methanol and 20 mM ammonium acetate buffer (pH 3.5) were used to provide maximum analyte interaction and resolution. The method was found to have good linearity for both analytes ( R 2 > 0.999) over the concentration ranges studied. Limits of detection were 0.23 and 0.15 μg/mL for MET and CAM, respectively, and corresponding limits of quantification were 0.35 and 0.42 μg/mL, respectively. Recovery tests gave high precision values of 98.2%–101.5%, while intra‐ and inter‐day precision in relative standard deviation (RSD) was below 2%. The method was effectively applied for the analysis of commercial tablet formulations, confirming its reliability and suitability for routine quality control and regulatory analyses. Overall, the validated RP‐HPLC method provides a sensitive, accurate, and efficient means of simultaneous determination of MET and CAM in pharmaceutical dosage forms.

The aim of this study was to develop a simple, accurate, and precise method for the estimation of bupropion and dextromethorphan in a fixed-dose combination of tablets and robust high-performance liquid chromatography for assay analysis of such a fixed combination. Chromatographic analysis was performed and separations were achieved on a Denali C18 150 × 4.6 mm, 5 micron using a mobile phase composition of acid and acetonitrile in the ratio of 600:400 ( ), flow rate of 1.0 mL/min, injection volume is 10 µL and run time of 6 min in isocratic elution. Ultraviolet (UV) detection was performed at a wavelength of 221 nm. The temperature was maintained at 30 °C. Well-resolved peaks were observed with a high number of theoretical plates, lower tailing factor, and reproducible relative retention time. The method was validated, and all validation parameters were found to be within the acceptance limits. A simple, accurate, and precise method has been developed for estimating bupropion and dextromethorphan in a fixed dose combination of tablets. The optimized method included the following parameters: column temperature of 30 °C, 40% acetonitrile as the mobile phase, and flow rate of 1.0 mL/min. Retention times were 2.25 min and 3.12 min for bupropion and dextromethorphan, respectively. The method was found to be linear in the range of 17.5-105 µg/mL [for R < 0.999) and 7.5-45 µg/mL (for R > 0.999] for bupropion and dextromethorphan, respectively. Both active pharmaceutical ingredients dissolved more than 90% within 5 min. The current study describes a new, simple, reliable, and economical elution reversed-phase high performance liquid chromatography method for estimating bupropion and dextromethorphan in a fixed combination tablet dosage form. The forced degradation studies were conducted using several degradation conditions such as acidic, alkali, oxidation, thermal, UV, and neutral conditions; the proposed method was effectively employed from the resolution of sample peaks. To the best of our knowledge, no such detailed and stability-indicating method has been reported for a fixed tablet dosage form.

The aim of this research was the production of extrudates for the treatment of hypertension and heart failure and the investigation of the degradation of the peptidomimetic drug enalapril maleate (EM) during hot-melt extrusion (HME). A fast HPLC method was developed to quantify enalapril maleate and possible degradation products. Screening experiments revealed that the diketopiperazine derivative (Impurity D) was the main degradation product. Hot-melt extrusion of enalapril maleate with the polymer Soluplus® enabled extrusion at 100 °C, whereas a formulation with the polymer Eudragit® E PO could be extruded at only 70 °C. Extrusion at 70 °C prevented thermal degradation. A stabilizing molecular interaction between enalapril maleate and Eudragit® E PO was identified via FT-IR spectroscopy. Dissolution studies were carried out to study the influence of the formulation on the dissolution behavior of enalapril maleate. These promising results can be transferred to other thermo-sensitive and peptidomimetic drugs to produce extrudates which can be used, for instance, as feedstock material for the production of patient-specific dosage forms via Fused Deposition Modeling (FDM) 3D printing.

Hydrophobic interaction chromatography (HIC) is a chromatographic technique that mainly targets the separation of biomolecules (intact proteins, monoclonal antibodies, etc.) based on the difference in surface hydrophobicity while applying non‐denaturing conditions. This protocol paper provides guidelines for setting‐up robust HIC analysis and considers the instrument configuration, mobile‐phase and sample preparation, as well as chromatographic conditions and settings. The separation of a mixture of intact proteins and monoclonal antibodies is demonstrated by applying conventional HIC conditions, that is, using a mildly hydrophobic (C4) stationary phase in combination with an inverse ammonium sulphate gradient dissolved in aqueous phosphate buffer. The effect of sample‐preparation conditions on sample breakthroughs is presented. Finally, good run‐to‐run repeatability (relative standard deviation < 2%) is demonstrated for five different columns obtained from three different column lots, considering chromatographic retention, peak width, peak area and column pressure.