ENANTIOMERIC SEPARATION OF RIVAROXABAN BY A CHIRAL LIQUID CHROMATOGRAPHIC METHOD

Objective: To develop a novel,simple, selective and enantiomeric separation of rivaroxaban by a chiral liquid chromatographic method as per ICH guidelines.Methods: An enantioselective reversed phase high performance liquid chromatographic method was developed and validated. The enantiomers of rivaroxaban was resolved on a Chiralcel OD-H (250 mm × 4.6 mm, 5 mm) column using a mobile phase system containing n-hexane –isopropanol (50: 50 v/v/) and column temperature at 35°C. The resolution between the enantiomers was not less than 2.0. The developed method was validated according to ICH guidelines.Results: The calibration curve was found to be linear over the concentration range of 0.075–1.2µg/mL (r2= 0.9996). The limit of detection and limit of quantification of the (R)-enantiomer were found to be 0.025 and 0.075µg/mL, respectively, for 20 mL injection volume. The percentage recovery of the (R)-enantiomer ranged from 92.06 to 105.9 in bulk drug samples of rivaroxaban. The final optimized method was successfully applied to separate the (R)-enantiomer from rivaroxaban and was proved to be reproducible, accurate and robust for the quantitative determination of the (R)-enantiomer in Rivaroxaban.Conclusion: A novel, simple, selective and simple, selective and enantiomeric separation of rivaroxaban by a chiral liquid chromatographic method was developed as per ICH guidelines.Hence, the method can be used for routine analysis in pharmaceutical industry.Â

Expression, purification, crystallization and preliminary X-ray diffraction analysis of conjugated bile salt hydrolase from Bifidobacterium longum

Conjugated bile salt hydrolase (BSH) catalyses the hydrolysis of the amide bond that conjugates bile acids to glycine and to taurine. The BSH enzyme from Bifidobacterium longum was overexpressed in Escherichia coli BL21(DE3), purified and crystallized. Crystallization conditions were screened using the hanging-drop vapour-diffusion method. Crystal growth, with two distinct morphologies, was optimal in experiments carried out at 303 K. The crystals belong to the hexagonal system, space group P622 with unit-cell parameters a = b = 124.86, c = 219.03 Angstrom, and the trigonal space group P321, with unit-cell parameters a = b = 125.24, c = 117.03 Angstrom. The crystals diffracted X-rays to 2.5 Angstrom spacing. Structure determination using the multiple isomorphous replacement method is in progress

Expression, purification, crystallization and preliminary X-ray diffraction analysis of conjugated bile salt hydrolase from Bifidobacterium longum

Conjugated bile salt hydrolase (BSH) catalyses the hydrolysis of the amide bond that conjugates bile acids to glycine and to taurine. The BSH enzyme from Bifidobacterium longum was overexpressed in Escherichia coli BL21(DE3), purified and crystallized. Crystallization conditions were screened using the hanging-drop vapour-diffusion method. Crystal growth, with two distinct morphologies, was optimal in experiments carried out at 303 K. The crystals belong to the hexagonal system, space group P622 with unit-cell parameters a = b = 124.86, c = 219.03 Angstrom, and the trigonal space group P321, with unit-cell parameters a = b = 125.24, c = 117.03 Angstrom. The crystals diffracted X-rays to 2.5 Angstrom spacing. Structure determination using the multiple isomorphous replacement method is in progress

Towards Streaming Speech-to-Avatar Synthesis

Streaming speech-to-avatar synthesis creates real-time animations for a virtual character from audio data. Accurate avatar representations of speech are important for the visualization of sound in linguistics, phonetics, and phonology, visual feedback to assist second language acquisition, and virtual embodiment for paralyzed patients. Previous works have highlighted the capability of deep articulatory inversion to perform high-quality avatar animation using electromagnetic articulography (EMA) features. However, these models focus on offline avatar synthesis with recordings rather than real-time audio, which is necessary for live avatar visualization or embodiment. To address this issue, we propose a method using articulatory inversion for streaming high quality facial and inner-mouth avatar animation from real-time audio. Our approach achieves 130ms average streaming latency for every 0.1 seconds of audio with a 0.792 correlation with ground truth articulations. Finally, we show generated mouth and tongue animations to demonstrate the efficacy of our methodology.Comment: Submitted to ICASSP 202

An Ocular Route of Administration for Drugs through Novel Approach of Self-microemulsifying Formulation – A Systematic Review

Drug administration through ocular route is associated to treat the ophthalmic diseases; glaucoma, conjunctivitis, retinal disorder, and diabetic eye problems. Various ophthalmic formulations as nanoparticles, nanoemulsion, microemulsion, nanosphere, microsphere, and nanosuspension have been developed. Such novel formulations have ability to prolonged the contact time of dosage form on ocular surface and reduce the drug elimination. Microemulsion is the thermodynamically stable and clear dispersion of oil and aqueous phase stabilized by surfactant and cosurfactant with target droplet size up to100 nm. Self-microemulsifying drug delivery system (SMEDDS) approach is generally adopted to enhance bioavailability of poorly water-soluble drugs. SMEDDS is the appropriate system for ocular drug delivery as it improves the ocular drug retention, high ocular absorption, and extended duration of action. The surfactant/cosurfactant combination used in SMEDDS has capacity to improve drug permeation across the cornea. The review gives the highlights to understand the feasibility of SMEDDS as dosage form for ocular administration to increases or improve the bioavailability. Review highlights the developmental steps of SMEDDS for the ocular drug administration as novel dosage forms to improve patient compliance

Candida bombicola cells immobilized on patterned lipid films as enzyme sources for the transformation of arachidonic acid to 20-HETE

Preparation of biocompatible surfaces for immobilization of enzymes and whole cells is an important aspect of biotechnology due to their potential applications in biocatalysis, biosensing, and immunological applications. In this report, patterned thermally evaporated octadecylamine (ODA) films are used for the immobilization of Candida bombicola cells. The attachment of the cells to the ODA film surface occurs possibly through nonspecific interactions such as hydrophobic interactions between the cell walls and the ODA molecules. The enzyme cytochrome P450 present in the immobilized yeast cells on the ODA film surface was used for the transformation of the arachidonic acid to 20-hydroxyeicosatetraenoic acid (20-HETE). The assembly of cells on the hydrophobic ODA surface was confirmed by quartz crystal microgravimetry (QCM), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). SEM images confirmed the strong binding of the yeast cells to the ODA film surface after biocatalytic reactions. Moreover, the biocomposite films could be easily separated from the reaction medium and reused