We developed a cost-effective and eco-friendly click biosynthesis of small molecule quercetin–gold quantum dots (QRT–AuQDs) involving quick conjugation using an ultrasonication method at ambient temperature by utilizing QRT and gold ions in the proportion of 0.1 : 1 (molar ratio). A comparatively very short amount of time (60 seconds) was required as compared to conventional procedures. The present biomimetics research relates to the isolation of bioactive QRT by the circularly spread silica gel layer technique (CSSGLT) and characterization (UV-Vis, FTIR, NMR and DSC analysis). Characterization of the synthesized QRT–AuQDs conjugated complex was carried out by UV-Vis, HR-TEM, DLS, zeta potential and X-ray diffraction. The main objective of the present work was to study the comparative anticancer activity of QRT and QRT–AuQDs on human lung cancer HOP-62 and leukemia K-562 cell lines. The results suggested that QRT–AuQDs showed potential for applications in anticancer treatment and were found to be a more cytotoxic agent in comparison to QRT, causing > 50% inhibition of cancer cells at the concentration < 10⁻⁷ M. Hence, small molecule conjugated QRT–AuQDs can be used as a promising material for biomedical, bioengineering and anti-infectives applications.

We report the controlled growth of biologically active compounds: gold nanoparticles (AuNPs) in various shapes, including their green synthesis, characterization, and studies of their applications towards biological, degradation and recycling. Using spectroscopic methods, studies on responsive binding mechanisms of AuNPs with biopolymers herring sperm deoxyribonucleic acid (hsDNA), bovine serum albumin (BSA), dyes degradation study, and exquisitely gold separation studies/recovery from nanowaste, COVID-19 testing kits, and pregnancy testing kits are discussed. The sensing ability of the AuNPs with biopolymers was investigated via various analytical techniques. The rate of degradation of various dyes in the presence and absence of AuNPs was studied by deploying stirring, IR, solar, and UV-Vis methods. AuNPs were found to be the most active cytotoxic agent against human breast cancer cell lines such as MCF-7 and MDAMB-468. Furthermore, an economical process for the recovery of gold traces from nanowaste, COVID-19 detection kits, and pregnancy testing kits was developed using inexpensive and eco-friendly α-cyclodextrin sugar. This method was found to be easy and safest in comparison with the universally accepted cyanidation process. In the future, small gold jewelry makers and related industries would benefit from the proposed gold-recycling process and it might contribute to their socio-economic growth. The methodologies proposed are also beneficial for trace-level forensic investigation.

A selective inhibitor of cyclooxygenase-2 (COX-2), Celecoxib (CEB), known for its anti-inflammatory properties, can exhibit polymorphism, with Form III often emerging as an undesired crystalline impurity during the green manufacturing process of the preferred Form I. Controlling the Form III content in the drug product is crucial, as different crystalline forms can impact drug bioavailability and therapeutic efficacy. This study presents a method to quantify the weight percentage of Form III in the bulk of CEB Form I by employing powder X-ray diffraction (PXRD). Initially, pure Form I and III of CEB were characterized using DSC, FTIR, and PXRD, supporting the method’s development. Binary mixtures, with varying ratios of CEB polymorphs Form I and Form III, were prepared and analyzed using continuous scans over an angular (2θ) range of 2–40. The calibration curve was constructed using 2θ unique peaks for Form I and Form III, respectively. Linear regression analysis exhibited a strong linear relationship within the weight ratio range of 1–20%. The developed method was validated to assess recovery, precision, ruggedness, limits of detection, and quantitation. These findings indicate that the method exhibits repeatability, sensitivity, and accuracy. The newly developed and validated PXRD method is applicable for quality control of CEB Form I produced through the green melt crystallization process by detecting low levels of Form III polymorphic impurity. This research significantly contributes to ensuring the clinical efficacy and manufacturing quality of Celecoxib by providing a reliable method for controlling polymorphic impurities.

This study investigates the potential of binary mixtures of gliclazide (GCL) and Vitamin C i.e. ascorbic acid (ASC) in various molar ratios to address the minimal aqueous solubility and dissolution characteristics of GCL. The results reveal that GCL and ASC form a eutectic mixture, at a 1:1 molar ratio exhibiting the eutectic melting temperature (TEut) at 148.60°C, as determined through phase diagram construction employing differential scanning calorimetry (DSC) and thermo-microscopy. The presence of eutectic formation was confirmed by powder X-ray diffraction (PXRD) and furrier transform infrared (FTIR) spectroscopy indicating the absence of molecular interaction within the two components in the solid state. GCL-ASC eutectic mixture significantly enhanced the solubility, wettability, and dissolution rate of GCL, with ASC serving as a water-soluble carrier. Furthermore, in the presence of excipients, the GCL-ASC mixture exhibited a superior dissolution rate compared to pure GCL. These findings underscore the potential of eutectic mixtures as a promising strategy for improving the solubility and dissolution performance of poorly water-soluble drugs like gliclazide, highlighting the importance of this work in advancing pharmaceutical formulation and bioavailability enhancement.