Quantitation of residual sodium dodecyl sulfate in meningococcal polysaccharide by gas chromatography-mass spectrometry

Evaluation of GC-MS for identification and characterization of pneumococcal serotype 24A, 24B, and 24F capsular polysaccharide

Analysis of pneumococcal polysaccharides (PnPs) has been an arduous task, especially in similar serotypes. Pneumococci invades the host immune response by modulating capsule structure with small genetic changes making them indistinguishable from similar serotypes by conventional modes of analysis. The new serotype 24F causing invasive pneumococcal-resistant infection is an analytical challenge for its analysis as related serotypes 24A and 24B Ps share a common backbone. The difference in the branched chain which contains arabinitol and ribitol in 24F and 24B respectively are stereoisomers making their identification even more challenging. The composition analysis by GC-MS revealed distinct peaks for arabinitol in 24F and 24A Ps and ribitol in Pn 24B serotype polysaccharide. The mass spectral analysis confirmed their identification along with a heterologous cross-reactivity which confirmed anti-Pn-24F mAb reactive to Pn 24B than Pn 24A. The quantitative analysis of pneumococcal 24A, 24B and 24F using GC-MS showed sensitive analysis over the concentration range 3.125-200 μg/mL with regression coefficient >0.99 making ideal modality for the characterization, identification, and quantitation of pneumococcal 24A, 24B and 24F similar serotypes.

A Method for the Colorimetric Quantification of Sodium Lauryl Sulphate in Tablets: A Proof of Concept

The deformulation stage of original drug products, which includes the quantification of critical excipients, is crucial for the successful development of generic drug products of solid dosage form. Sodium lauryl sulphate (SLS) belongs to the group of critical excipients due to its influence on the bioavailability of drugs, such as metformin. The purpose of this work is to carry out a feasibility study in order to develop a simple, economical, and robust analytical method for the quantification of SLS in metformin-containing tablets after their dissolution in water. Firstly, SLS is extracted with chloroform in acidic conditions, followed by the addition of methylene blue (MB) in order to form a SLS-MB ion pair, which is then measured photometrically at a wavelength of 651 nm. Additionally, interference from matrix components (excipients and APIs) was assessed, and it was found that metformin also forms a blue complex; therefore, this specific extraction method was developed. Other matrix components did not interfere with SLS determination. This method shows a well-estimated precision of 3.3% and accuracy of 5%, a calibration linearity of R2 = 0.99990, and a working range of 0.38 µg/mL to 10 µg/mL of SLS in water. The midpoint of the calibration graph corresponds to the concentration of SLS obtained by dissolving a single tablet in 1 L of water. This method seems appropriate for total SLS determination in tablets and can be applicable for deformulation.

Revealing the potential bioactive components and mechanism of Qianhua Gout Capsules in the treatment of gouty arthritis through network pharmacology, molecular docking and pharmacodynamic study strategies

Recent clinical studies have confirmed the effectiveness of Qianhua Gout Capsules (QGC) in the treatment of gouty arthritis (GA). However, the specific regulatory targets and mechanisms of action of QGC are still unclear. To address this gap, we utilized network pharmacology, molecular docking, and pharmacodynamic approaches to investigate the bioactive components and associated mechanisms of QGC in the treatment of GA. By employing UPLC-Q Exactive-MS, we identified the compounds present in QGC, with active ingredients defined as those with oral bioavailability ≥30 % and drug similarity ≥0.18. Subsequently, the targets of these active compounds were determined using the TCMSP database, while GA-related targets were identified from DisGeNET, GeneCards, TTD, OMIM, and DrugBank databases. Further analysis including PPI analysis, GO analysis, and KEGG pathway enrichment was conducted on the targets. Validation of the predicted results was performed using a GA rat model, evaluating pathological changes, inflammatory markers, and pathway protein expression. Our results revealed a total of 130 components, 44 active components, 16 potential shared targets, GO-enriched terms, and 47 signaling pathways related to disease targets. Key active ingredients included quercetin, kaempferol, β-sitosterol, luteolin, and wogonin. The PPI analysis highlighted five targets (PPARG, IL-6, MMP-9, IL-1β, CXCL-8) with the highest connectivity, predominantly enriched in the IL-17 signaling pathway. Molecular docking experiments demonstrated strong binding of CXCL8, IL-1β, IL-6, MMP9, and PPARG targets with the top five active compounds. Furthermore, animal experiments confirmed the efficacy of QGC in treating GA in rats, showing reductions in TNF-α, IL-6, and MDA levels, and increases in SOD levels in serum. In synovial tissues, QGC treatment upregulated CXCL8 and PPARG expression, while downregulating IL-1β, MMP9, and IL-6 expression. In conclusion, this study applied a network pharmacology approach to uncover the composition of QGC, predict its pharmacological interactions, and demonstrate its in vivo efficacy, providing insights into the anti-GA mechanisms of QGC. These findings pave the way for future investigations into the therapeutic mechanisms underlying QGC's effectiveness in the treatment of GA.

Electrochemical sensor based on screen printed carbon electrode-zinc oxide nano particles/molecularly imprinted-polymer (SPCE-ZnONPs/MIP) for detection of sodium dodecyl sulfate (SDS)

The foremost objective of this work is to prepare a novel electrochemical sensor-based screen-printed carbon electrode made of zinc oxide nanoparticles/molecularly imprinted polymer (SPCE-ZnONPs/MIP) and investigate its characteristics to detect sodium dodecyl sulfate (SDS). The MIP that is polyglutamic acid (PGA) film was synthesized via in situ electro-polymerization. The SDS's recognition site was left on the surface of the PGA film after extraction using the cyclic voltammetry (CV) technique, facilitating the specific detection of SDS. Moreover, the ZnONPs (∼71 nm, polydispersity index of 0.138) were synthesized and effectively combined with the MIP by a drop-casting method, enhancing the current response. The surface of the prepared SPCE-ZnONPs/MIP was characterized by scanning electron microscopy and energy dispersive X-ray. Besides, the electrochemical performance of the SPCE-ZnONPs/MIP was also studied through CV and differential pulse voltammetry (DPV) techniques. As an outstanding result, it is observed that the current response of SPCE-ZnONPs/MIP for detection of SDS remarkably increased almost four times higher from 0.009 mA to 0.041 mA in comparison with bare SPCE. More importantly, the proposed SPCE-ZnONPs/MIP exhibited an excellent selectivity (in the presence of interfering molecules of Ca²⁺, Pb²⁺, as well as sodium dodecylbenzene sulfonate (SDBS)), sensitivity, reproducibility, and repeatability. Since the modified sensor offers portability, it is suitable for in situ environment and cosmetic monitoring.