Kuldeep V. Joshi

Effect of p-sulfonatocalix[4]resorcinarene (PSC[4]R) on the solubility and bioavailability of a poorly water soluble drug lamotrigine (LMN) and computational investigation

As a part of our research investigations to unfold the chemistry of calixresorcinarene, we studied the formation of an inclusion complex with p-sulfonatocalix[4]resorcinarene (PSC[4]R) of a poorly water soluble drug lamotrigine (LMN). The complete complexation of the drug was achieved after 48 h of stirring with PSC[4]R in water and evaporation of the water to give a solid complex. The inclusion complex between PSC[4]R and LMN was studied by different analytical techniques including FT-IR, PXRD and UV-VIS spectroscopy. The complexation was determined by thermal analysis and a phase solubility study. The prepared complexes exhibited improved in vitro dissolution profile and decreased in vivo acute oral toxicity compared to the pure drug. The results of the phase solubility experiments are in good conformity to signify the formation of 1 : 1 PSC[4]R : LMN complexes. Computational studies were performed to understand the intermolecular association of this inclusion complex using docking and short dynamic simulations. The purpose of this study was to enhance solubility resulting in high dissolution rate and bioavailability of this essentially poorly water soluble drug LMN.

Analytical detection and method development of anticancer drug Gemcitabine HCl using gold nanoparticles.

A simple, rapid, cost effective and extractive UV spectrophotometric method was developed for the determination of Gemcitabine HCl (GMCT) in bulk drug and pharmaceutical formulation. It was based on UV spectrophotometric measurements in which the drug reacts with gold nanoparticles (AuNP) and changes the original colour of AuNP and forms a dark blue coloured solution which exhibits absorption maximum at 688nm. The apparent molar absorptivity and Sandells sensitivity coefficient were found to be 3.95×10(-5)lmol(-1)cm(-1) and 0.060μgcm(-2) respectively. Beers law was obeyed in the concentration range of 2.0-40μgml(-1). This method was tested and validated for various parameters according to ICH guidelines. The proposed method was successfully applied for the determination of GMCT in pharmaceutical formulation (parental formulation). The results demonstrated that the procedure is accurate, precise and reproducible (relative standard deviation <2%). As it is simple, cheap and less time consuming, it can be suitably applied for the estimation of GMCT in dosage forms.

Novel cationic fullerene derivatized s-triazine scaffolds as photoinduced DNA cleavage agents: design, synthesis, biological evaluation and computational investigation

A series of novel cationic fullerene (C60) derivatives, bearing substituted s-triazine moiety as a side arm, synthesized by using the 1,3 dipolar cycloaddition reaction of C60 with azomethine ylides generated from the corresponding Schiff bases of substituted s-triazine is reported. All the synthesized compounds were characterized by elemental analysis, FT-IR, 1H NMR, 13C NMR and ESI-MS. The compounds 7a, 7d, 7e and 7f cleaved the supercoiled pBR322 DNA into nicked form efficiently upon visible light irradiation in the presence of NADH. The photoinduced superoxide radical and hydroxyl radical generated may act as molecular species causing the DNA scission. Further, the interaction of synthesized molecules with pBR322 plasmid DNA was investigated using computational approaches.

Polyvinyl pyrrolidone modified ZnS nanoparticles as a highly selective and sensitive nanosensor for the iodide ion

In this communication we report polyvinyl pyrrolidone modified ZnS nanoparticles as a highly selective and sensitive nanosensor for iodide ions. The detection mechanism was demonstrated by the heavy atom effect. The sensor has been successfully applied to estimate the iodide ion in urine samples and highly concentrated brine solutions.

Thioctic acid modified gold nanoparticles for highly specific and ultrasensitive detection of lanthanum in soil and water

We report ultrasensitive ligand to metal charge transfer (LMCT) based thioctic acid modified gold nanoparticles for the detection of lanthanum ion with excellent sensitivity (50 nM) and selectivity over other cations.