Current Issue : January-March Volume : 2026 Issue Number : 1 Articles : 7 Articles
Imipenem (IMP) and Cilastatin (CILA) are co-formulated β-lactam antibiotics extensively used in the management of severe bacterial infections, requiring reliable analytical methods for simultaneous estimation to ensure quality control and regulatory compliance. A simple, accurate and reproducible reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed and validated for the concurrent quantification of IMP and CILA in bulk and pharmaceutical dosage forms in accordance with ICH Q2(R1) guidelines. Chromatographic separation was performed on a Zodiac Sil RP-C18 column (250 × 4.6 mm, 3.0 µm) using a mobile phase of methanol and phosphate buffer (pH 3.0) in a 70:30 (v/v) ratio at a flow rate of 1.0 mL/min, with UV detection at 240 nm and an injection volume of 10 µL. IMP and CILA were well resolved with retention times of 2.45 and 3.19 min, respectively and a resolution greater than 3.0. The method exhibited excellent linearity in the ranges of 50–250 µg/mL for IMP and 5–25 µg/mL for CILA with correlation coefficients (r²) of 0.999 for both drugs. Accuracy studies demonstrated mean recoveries of 99.54% for IMP and 100.75% for CILA, while intra- and inter-day precision values were within 2% RSD. The method demonstrated high sensitivity with LOD/LOQ values of 2.16/6.62 µg/mL for IMP and 0.037/0.11 µg/mL for CILA. Robustness was confirmed under deliberate variations in flow rate and mobile phase composition. The proposed method is rapid, sensitive and reliable, making it highly suitable for routine quality control and stability testing in pharmaceutical industries....
This paper reports on a validated, stability-indicating high-performance thin-layer chromatography (HPTLC)-based assay for the quantification of nitrofurazone in an ointment formulation. The simple and rapid HPTLC analysis was performed on silica gel 60 F254 HPTLC plates using toluene–acetonitrile–ethyl acetate–glacial acetic acid (6:2:2:0.1, v/v) as the mobile phase and chloroform–acetone (9:1, v/v) as the solvent. The method was validated in accordance with the guidelines set by both the International Council for Harmonisation (ICH) and the United States Food and Drug Administration (FDA). Nitrofurazone appeared as a sharp band with a RF value of 0.18. The method showed excellent linear regression between the concentration ranges of 30–180 ng/band (R = 99.99%). The limit of detection was found to be 10.39 ng/band, and the limit of quantification was 31.49 ng/band. The forced degradation of nitrofurazone via photolysis, oxidation, acid and alkaline hydrolyses confirmed the assay’s suitability for stability studies involving nitrofurazone. Therefore, the method is considered suitable for the routine quality control of nitrofurazone ointment....
CYP1A2 activity plays a critical role in the metabolism of drugs such as caffeine, clozapine, propranolol, and warfarin. In pharmacogenomic studies, caffeine is a probe drug of choice for CYP1A2 phenotyping. Due to the non-invasive nature of sampling, saliva is an alternative biofluid to plasma for monitoring caffeine levels. This study reports on a validated HPTLC method for quantifying salivary caffeine levels, which can support future studies on CYP1A2 phenotyping employing caffeine as a probe drug. The HPTLC method, using silica gel 60 F254 plates and acetone/toluene/chloroform (4:3:3, v/v/v) as the mobile phase, has detection and quantification limits of 2.42 and 7.34 ng/band, respectively. An optimised saliva processing protocol using a 1:1 dilution with methanol was also established. Five saliva sample sets collected 0–4 h after ingestion of 100 mg caffeine were analysed using the developed and validated HPTLC method, which demonstrated that salivary caffeine concentrations peak around 1 h post ingestion and then gradually decrease over the study period. Thus, the developed HPTLC method can be used to analyse caffeine levels in saliva and to support CYP1A2 phenotyping using caffeine as a probe drug....
Nitrosamine impurities, including N-nitrosodimethylamine (NDMA) and N-nitrosodiethylamine (NDEA), are classified as genotoxic and carcinogenic. Their occurrence in pharmaceuticals, even at trace levels, necessitates sensitive analytical methods. Palaveratone, a steroidal active pharmaceutical ingredient, requires rigorous monitoring for these impurities. This study aimed to develop and validate a simple, reliable and sensitive RP-HPLC method for the quantification of NDMA and NDEA in palaveratone, following ICH Q2(R1) and ICH M7(R1) guidelines. Chromatographic separation was performed on a Platisil C18 column (250 × 4.6 mm, 5 µm) with an isocratic mobile phase of potassium dihydrogen phosphate buffer and acetonitrile (10:90 v/v). The flow rate was 1.0 mL/min, detection wavelength 296 nm and injection volume 20 µL. The method was validated for specificity, linearity, precision, accuracy, detection limit (DL) and quantitation limit (QL). NDMA and NDEA were well resolved without interference. The DL and QL were 0.035 ppm and 0.093 ppm, respectively. Linearity was excellent (R² = 0.999), recoveries ranged from 98.2–115.2% and precision studies yielded %RSD values <6%. Intermediate precision met the cumulative acceptance limit of ≤20.0. The validated method was found sensitive, accurate and reproducible, making it suitable for routine quality control and regulatory compliance of nitrosamine impurities in palaveratone....
Dasatinib and lenvatinib are tyrosine kinase inhibitors widely prescribed for hematological malignancies and solid tumors. Their simultaneous estimation in pharmaceutical dosage forms is critical for quality control, therapeutic safety and regulatory compliance, especially when used in combination regimens. Chromatographic separation was achieved on a Shim-pack C18 column (150 × 4.6 mm, 5 μm) using an isocratic mobile phase of phosphate buffer (0.05 M, pH 3.0) and acetonitrile (35:65, v/v) at a flow rate of 1.0 mL/min. Detection was performed at 265 nm with a 10 μL injection volume. Validation parameters included system suitability, specificity, linearity, accuracy, precision, robustness and sensitivity. Dasatinib and lenvatinib were eluted at 2.4 and 3.5 minutes, respectively, with sharp and well-resolved peaks. The method demonstrated excellent linearity (R² > 0.9999), recoveries of 99–101% and %RSD < 2%. LODs were 0.082 μg/mL and 1.13 μg/mL, respectively. Assay results of marketed formulations confirmed drug content within 99–101% of label claims. The validated RP-HPLC method was rapid, accurate, precise and robust, making it suitable for routine quality control, stability testing and regulatory applications....
The acquisition of high-purity impurities is pivotal for structural identification and an origin analysis, thereby laying a critical foundation for subsequent toxicological evaluation, quality standard development, and process optimization. This study investigated the feasibility of using a solvent gradient twin-column recycling chromatography technique for the separation and purification of multiple trace impurities in iohexol. In this approach, a modifier with a weaker elution strength than the mobile phase is introduced between two chromatographic columns to form a step gradient solvent system. This gradient slows down the leading edge of the elution band relative to the rear edge, inducing a band compression effect that counteracts band broadening and enhances the chromatographic resolution. By optimizing parameters such as the mobile phase composition, elution mode, and modifier flow rate, three trace impurities were successfully separated and purified from iohexol. Their respective purities were improved from initial concentrations of 0.36%, 0.35%, and 0.15% to 97.82%, 91.56%, and 81.56%, respectively. Leveraging the band compression effect on the target components, the impurities were simultaneously purified and concentrated. These results demonstrate that the proposed method is highly effective for the rapid isolation and preparation of trace pharmaceutical impurities....
Background/Objectives: Bangkeehwangkee-tang (BHT) is a traditional herbal formula composed of six medicinal herbs: Sinomenii Caulis et Rhizoma, Astragali Radix, Atractylodis Rhizoma Alba, Zingiberis Rhizoma Recens, Zizyphi Fructus, and Glycyrrhizae Radix et Rhizoma. BHT has been widely used for its immunomodulatory and anti-inflammatory effects. This study aimed to develop a reliable analytical method for the simultaneous determination of 22 marker compounds to ensure consistent quality control and to ensure consistent efficacy in both clinical and non-clinical studies of BHT. Methods: An ultraperformance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) method based on multiple reaction monitoring was developed and validated for the simultaneous determination of 22 marker compounds in BHT. The method was evaluated for selectivity, linearity (coefficient of determination, r2), sensitivity (limit of detection (LOD) and limit of quantification (LOQ)), accuracy (recovery), and precision (relative standard deviation (RSD)) in accordance with guidelines. Results: The developed method exhibited excellent selectivity and linearity (r2 ≥ 0.9913) for all target compounds. The LOD and LOQ ranged from 0.09 μg/L to 326.58 μg/L and 0.28 μg/L to 979.75 μg/L, respectively. The recovery ranged from 90.36% to 113.74%, and precision (RSD) was ≤15%, confirming the method’s reliability. The application of the method to various BHT samples revealed substantial variations in the marker compound contents, particularly for sinomenine, magnoflorine, and glycyrrhizin. Conclusions: These findings highlight the necessity for standardized quality control of BHT and demonstrate that the developed UPLC–MS/MS method is a practical and reliable tool for performing quality assessment of traditional herbal formulas....
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