Current Issue : July-September Volume : 2026 Issue Number : 3 Articles : 5 Articles
The primary objective of the current study is to establish and validate for the first time a method to determine and quantify praziquantel (PZQ) and its main degradation products loaded in poly(methyl methacrylate–co-2-(diethylamino)ethyl methacrylate) P(MMA-co-DEAEMA) microparticles. A high-performance liquid chromatography (HPLC) approach was developed and validated in accordance with the United States Pharmacopeia (USP) guidelines, addressing parameters such as accuracy, linearity, solution stability, precision, specificity, robustness, sensitivity, and system suitability. The method employed a gradient mobile phase consisting of ultrapure water and acetonitrile, flowing at a rate of 1 mL/minute over a Phenomenex Kinetex® C18 column (5 μm, 100 Å, 250 × 4.6 mm) maintained at 35 ◦C. Detection was performed at the wavelength of 210 nm using a DAD/UV detector. Samples of the active pharmaceutical ingredient (API) praziquantel, microencapsulated praziquantel, placebo, and a mixture of related substances (A, B, and C) were prepared with 0.5% formic acid in water/ethanol, 45:55 v/v as the diluent, and injected at 20 ◦C. The method demonstrated a limit of quantification (LOQ) of 0.20 μg/mL for praziquantel and related substances. The method exhibited an excellent linear response, with all correlation coefficients (R2) values exceeding 0.998, which is well above the recommended specified limit of R2 > 0.995. Percent recoveries fell within the acceptable range of (95.0–105.0%), and all results indicated a percentage of relative standard deviation (%RSD) ≤ 2.0, indicating a robust methodology. Thus, the proposed HPLC technique proved to be selective, accurate, sensitive, and consistent in analyzing both the material content and its main degradation products....
Accurate quantification in LC–MS experiments becomes challenging when analytes overlap both chromatographically and in mass spectra, as conventional extracted ion chromatogrambased methods can yield biased results by double-counting shared isotope signals. This limitation is particularly relevant for oligonucleotides, where degradation products and synthetic impurities frequently co-elute with the intended full-length product, complicating relative quantification. To address this, we developed DECAF, a straightforward and computationally efficient procedure for deconvoluting overlapping isotope patterns directly from MS1 data. The method models experimental isotope distributions as mixtures of theoretical templates across retention time, generating deconvoluted ion chromatograms whose peak areas accurately reflect the contributions of individual components. We demonstrate the utility of DECAF on two pharmaceutically relevant oligonucleotide mixture datasets, where it reliably estimated mixing proportions and enabled visualisation of component-specific elution profiles. Analysis of a typical sample required one to two minutes, underscoring the method’s practical efficiency. DECAF provides a transparent and accessible alternative to existing commercial software, with promising applications in pharmaceutical analysis and quality control....
Paracetamol (PAR) and orphenadrine citrate (ORPH) are two active substances commonly used in combination medicinal products, due to the analgesic effect of paracetamol and the muscle relaxant effect of orphenadrine, with a therapeutic indication of mild to moderate acute musculoskeletal pain. The aim of this work is to develop and validate an isocratic HPLC method for the simultaneous determination of PAR and ORPH in tablet formulation. Preliminary experiments showed that an analytical column with a chemically bound phenyl phase was required. A Box–Behnken design (BBD) was utilized to optimize the analytical method for two key responses, PAR asymmetry factor (AsymPAR) and ORPH capacity factor (kORPH), with three numerical factors: percentage of ACN in mobile phase (A); pH (B); and salt concentration in the aqueous solution (C). The optimized method consists of a Pinnacle DB Biphenyl (250 × 4.6 mm) 5 μm column, and a mobile phase of 37%/63% v/v ACN-NaH2PO4·H2O in 29 mM aqueous solution, pH = 2.5. The flow rate was set to 1.5 mL/min and detection occurred at 215 nm. After the optimization process the following chromatographic conditions were selected and the method was validated for various ICH parameters covering system suitability, specificity, linearity (R2 = 1.00), precision (%RSD ≤ 2), accuracy (98% ≤ %Recovery ≤ 102%), and robustness. Finally, the environmental friendliness of the novel method was assessed by using the Analytical GREEnness (AGREE) metric tool, obtaining a score of 0.67....
In addition to well-known traditional synthetic illicit drugs like cocaine, amphetamines, and heroin, an increasing number of new psychoactive substances (NPS) are appearing on the global drug market. Among them, cathinones represent a prominent class. These amphetamine-like compounds contain a stereogenic center, resulting in the possible presence of two enantiomers. Pure enantiomers of cathinone derivatives are not commonly available, and their production is cost-intensive. Thus, there is very little knowledge about the possible distinct effects of single enantiomers of cathinones. The objective of this study was to evaluate the stability of a set of eight cathinone derivatives, namely 3-methylethcathinone, 3-methylmethcathinone, 4-methylethcathinone, 4-methylmethcathinone, ethylone, 3,4-trimethylene-α-ethylaminovalerophenone, 3,4-tetramethylene- α-pyrrolidinovalerophenone, and 3,4-trimethylene-α-pyrrolidinobutiophenone, over a six-month period. Any racemization that may have occurred under different storage and solution conditions was monitored and compared. Pure enantiomeric fractions were collected on a multi-milligram scale using semi-preparative HPLC under isocratic normal-phase conditions. A Phenomenex Lux® i-Cellulose-5, 5 μm 250 × 10 mm column containing cellulose tris(3,5-dichlorophenylcarbamate) served as the chiral selector. The tests showed that aqueous conditions, pH, temperature, chemical structure, sunlight, and oxygen influence compound stability. The long-term storage of cathinone derivative enantiomers was found to be optimal as solids under deep-freezing conditions or in a slightly acidified solvent where they are protected from air and light....
Vertigoheel is a multicomponent medicinal product for the treatment of vertigo and dizziness, containing Anamirta cocculus, Conium maculatum, Ambra grisea, and Petroleum rectificatum. Although clinical efficacy has been reported, the chemical composition and underlying mechanisms remain incompletely characterized. Here, we applied ultra-high-performance liquid chromatography coupled to time-of-flight mass spectrometry (UHPLC-ToF-MS) to profile extracts of each ingredient and the final formulations. Untargeted analysis revealed 68,622 molecular features, and multivariate statistics highlighted ingredient-specific metabolites. Representative markers included picrotoxinin and picrotin from Anamirta cocculus, coniine and N-methylconiine from Conium maculatum, ambrinol and ambroxide from Ambra grisea, and santalyl phenylacetate and mercaptostearic acid from Petroleum rectificatum. Two compounds per ingredient were further quantified by targeted UHPLC-MS/MS, confirming their presence in drops and tablets at nanogram-per-dose levels with moderate variability across batches. These findings demonstrate that Vertigoheel retains characteristic constituents from its natural sources in all tested formulations. The established protocol enabled absolute quantification of neuroactive molecules such as picrotoxinin and coniine with minimal work-up. This molecular characterization provides new insight into Vertigoheel’s composition and supports further investigation of its mechanism of action using network pharmacology approaches....
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