No abstract

In present study, Cr(III) and Cr(VI) sorption capacity of Rosa damascena phytomass from aqueous solution was evaluated. The R. damascena phytomass biosorption revealed that smaller biosorbent size (< 0.4 g), dose (< 0.1 g), pH (2 and 5 for Cr VI and III) and 100 mg L-1 initial metal concentration were more suitable for better biosorption from aqueous medium. The Langmuir isotherm model and pseudo second order kinetic model fitted well to the data of Cr(III) and Cr(VI) biosorption. The negative value of Gibbs free energy (∆Gº) indicated the spontaneous absorption process. The R. damascena biomass pre-treatment enhanced biosorption considerably and it is concluded that the R. damascena biomass (waste material) might be used for biosorption of Cr(III) and Cr(VI) from aqueous solution.

Mirtazapine is a tetracyclic anti-depressant with poor water solubility. The aim of this study was to improve the dissolution rate of mirtazapine by delivering the drug as a liquisolid compact. Central composite design (CCD) was employed for the preparation of mirtazapine liquisolid compacts. In this, the impacts of two independent factors, i.e., excipient ratio (carrier:coating) and different drug concentration on the response of liquisolid system were optimized. Liquisolid compacts were prepared using propylene glycol as a solvent, microcrystalline cellulose as a carrier, and silicon dioxide (Aerosil) as the coating material. The crystallinity of the formulated drug and the interactions between the excipients were examined using X-ray powder diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR), respectively. The dissolution study for the liquisolid compact was carried out as per FDA guidelines. The results showed loss of crystallinity of the mirtazapine in the formulation and was completely solubilized in non-volatile solvent and equally dispersed throughout the powder system. Moreover, drug dissolution was found to be higher in liquisolid compacts than the direct compressed conventional tablets (of mirtazapine). The liquisolid technique appears to be a promising approach for improving the dissolution of poorly soluble drugs like mirtazapine.

In this research work, an isocratic, reversed-phase high-performance liquid chromatography-ultraviolet/visible detector method was developed for analysis of voriconazole standard (stock-solution) and in plasma samples. Optimization and validation of the method was carried out as per international guidelines. The method offered a simple liquid–liquid extraction technique, which exhibited best recovery of voriconazole along with fluconazole, i.e., internal standard. Different experimental conditions were tried and ultimately, the best outcomes were accomplished utilizing C-18 Perkin-Elmer® column with particulars of 150 mm length, 4.6 mm inner diameter and 5 μm particle size, protected by an RP-18 Perkin-Elmer® Pre-column guard cartridge with specifications of 10 μm particle size, 30 mm length and 4.6 mm inner diameter, utilizing mobile-phase of acetonitrile-water (ACN: H2O) in proportion of 60: 40 v/v, having a flow rate of 1.5 mL/min, and wavelength of 254 nm. All the analytes were observed to be separated in ≤7 min. A linear calibration curve was obtained at concentration range of 01–10 μg/mL of voriconazole. The correlation coefficient of voriconazole was observed to be 0.999, and average recovery (in percent) was 97.4%, whereas the relative standard deviation value was ≤2%. The lower limit of detection was 0.01 μg/mL, whereas, lower limit of quantification was 0.03 μg/mL, respectively. This developed method provided outstanding results of all validation parameters, i.e., recovery, accuracy, selectivity, precision and reproducibility. The method proposed for voriconazole analysis was applied effectively for further research investigation of voriconazole in human-plasma samples (to assess the pharmacokinetic parameters), pharmaceutical formulations and pharmacokinetic drug–drug interaction’s.