Current Pharmaceutical Analysis - Volume 20, Issue 2, 2024

Various technologies, like flow cytometry and cell sorting, have been established in fields of biomedical research. Fluorescence-activated cell sorting is one of the most powerful techniques to witness advancement in these years. This article aims to provide an in-depth overview of the FACS applications, along with regulatory considerations and qualification parameters for the instrument. Moreover, specifications of instruments from different brands with specialized features are mentioned. FACS is a cornerstone in clinical diagnostics. This review highlights the current advancements and versatility of this indispensable technology, and the said information would be a focal paradigm for the upcoming biomedical and pharmaceutical research.

The green synthesis of silver nanoparticles has garnered significant interest because of the unique physicochemical and biological properties they possess. These nanoparticles could have applications in a wide variety of fields, including biomedicine, cellular imaging, cosmetics, healthcare tourism, food and agriculture. The formation of nanoparticles is facilitated by the use of bionanofactories, or green synthesis processes, which utilise living organisms, biomolecules, and plant-based materials as bio reductive or bio sealing agents. Green chemistry is cost-effective in addition to being environmentally friendly, non-toxic, and biodegradable. By considering the results of recent studies using techniques like scanning electron microscopy, transmission electron microscopy, atomic force microscopy, ultraviolet/visible spectrophotometry, Fourier transform infrared spectroscopy or X-ray diffraction, we illuminate the most recent advances in green synthesis and the physicochemical properties of green silver nanoparticles. We also discuss the properties of silver nanoparticles that make them effective against bacteria, fungi, and parasites.

Background: Hair analysis plays a crucial role in forensic toxicology, offering a unique medium for long-term drug trace detection. This review emphasizes the evolution of electrochemical methods in analyzing hair for drug traces, underscoring their significance in forensic science. Methods: We examined recent advancements in electrochemical techniques, including voltammetry, amperometry, and electrochemical impedance spectroscopy, and their application in drug trace analysis. The review also explores the development of novel electrode materials and surface modifications, which enhance the detection capabilities of these methods. Results: Electrochemical methods have shown high sensitivity and specificity in detecting a range of drugs in hair. Innovations, like molecularly imprinted polymers and nanomaterials, have expanded the detectable substance range, offering more refined and accurate detection. Despite challenges, such as hair variability and external contamination, these methods have significantly improved the reliability of drug trace analysis. Conclusion: Electrochemical approaches to hair analysis represent a significant advancement in forensic toxicology. Their ability to provide sensitive, specific, and non-invasive analysis makes them valuable tools. Future developments, including portable device creation and integration with other analytical techniques, hold promise for further enhancing the scope and accuracy of drug trace detection in hair.

Background: Vigabatrin and gabapentin, commonly used antiepileptic drugs in clinics, lack a UV active chromophore and, therefore, require cumbersome derivatization methods for analysis by HPLC using fluorescence detection. This study demonstrated the use of NMR for their quantitative determination in pure form and their pharmaceutical formulations. Objectives: To develop a validated qNMR method for non-chromophoric drugs Vigabatrin and Gabapentin. Methods: The signal of methine proton of vigabatrin at 3.67 ppm relative to the signal of maleic acid at 6.17 ppm and the methylene signal of gabapentin at 2.88 ppm relative to the signal of caffeine at 7.75 ppm was used for qNMR. The developed method was validated with respect to linearity, limits of detection and quantitation, accuracy, precision, specificity and solution state stability. Results: Linearity range and r² were found to be from 2.66 to 42.11 mg/mL and 0.9999. The limit of detection and quantification were 0.0129 mg/mL and 0.0391 mg/mL, respectively, for vigabatrin. This method was found to be linear (0.9998) and specific within the gabapentin concentration range from 1.07 to 34.24 mg/mL of D2O. The limits of detection and quantification were 0.0248 mg/mL and 0.0751 mg/mL, respectively. Conclusion: Both methods were highly precise, with a calculated RSD of 0.60% and 0.76%, respectively. The robustness of the methods was revealed by changing pre and post-processing NMR parameters. The developed methods provide a simple and straight approach for the absolute determination of gabapentin and vigabatrin in bulk drugs and their marketed formulations without any pre-procedures.

Background: Gynostemma pentaphyllum (Thunb.) Makino has been linked to a number of pharmacological benefits, including hepatoprotective, anti-inflammatory, antioxidative, and antihyperlipidemic activities. Gypenoside XLVI (Gyp XLVI) was a significant triterpenoid saponin reported from a sweet-taste varietas G. pentaphyllum, which has inhibitory effects and causes apoptosis on human hepatocytes and hepatoma cells. Methods: A quick, precise, and sensitive method for the quantification and pharmacokinetic research of Gyp XLVI in rats was developed utilizing UPLC-MS/MS. When extracting blood samples, protein was precipitated using methanol. An internal standard (IS) was employed, which was tolbutamide. For the chromatographic separation, a C18 column (Waters Acquity) was used with mobile phases as 0.1% formic acid and acetonitrile. Multiple reaction monitoring was used as MS detection manner with electrospray ionization in negative mode. Results: Gyp XLVI had good linearity in the 1.36128;’1000.00 ng/mL concentration range. The intra- day and inter-day precisions (RSD%) and accuracy (RE%) were less than 12.7% or 8.29%, respectively. Gyp XLVI’s extraction recovery ranged from 89.5% to 104.2%. The matrix effects ranged from 75.3%128;’94.3%. The outcomes of matrix interference and recovery investigations complied with the necessary variability limitations. After three hours at room temperature (25°C), 24 hours in an auto-sampler (4°C), three freeze-thaw cycles, and 30 days of storage at -20°C, the analyte in rat plasma remained stable. Gyp XLVI pharmacokinetic investigations and quantification were conducted using the validated method. The AUC0-∞ values for intravenous administration (1 mg/kg) and oral administration (10 mg/kg) were 2213.9 ± 561.5 ng·h/mL and 1032.8 ± 334.8 ng·h/mL, respectively. Gyp XLVI had a half-life (t1/2z) of 2.5 ± 0.4 h in the rats after intravenous injection and 4.2 ± 0.9 h after oral administrations. Gyp XLVI had a comparatively low oral bioavailability of 4.56%. Conclusion: This is the first time that Gyp XLVI’s pharmacokinetic properties have been investigated through various administration routes. These findings will aid in our understanding of how Gyp XLVI was metabolized in rats and how it behaved pharmacologically in vivo.

Background: α-phenylethanol and its derivatives are important intermediates for the synthesis of a variety of chiral drugs. Methods: The interaction mechanism of the two enantiomers of α-phenylethanol with β-cyclodextrin (β-CD) was investigated using 1H-NMR and ROESY. The loading of β-CD as the host with the chiral drug intermediate α-phenylethanol as the guest was investigated using high-resolution NMR in D2O and quantum chemical calculations. Results: The results showed that both α-phenylethanol enantiomers were able to enter into the hydrophobic cavity of β-CD and undergo enantiospecific interactions, while the combination of 2D ROESY and quantum chemical calculations showed that the benzene ring of both R and S α- phenylethanol were inserted into the β-CD cavity toward the small-port end. However, the most stable poses of the two enantiomers were different, so the benzene ring of the S-enantiomer was more inclined to position the small-port end of β-CD than that of the R-enantiomer, which was reflected differently in the signals of 2D ROESY. Conclusion: β-CD can enantioselectively recognize the α-phenylethanol enantiomers, and the 2D ROESY method is a direct and powerful tool in the recognition process of chiral host and guest research.