Vignan University

About: Vignan University is a education organization based out in Guntur, Andhra Pradesh, India. It is known for research contribution in the topics: Control theory & CMOS. The organization has 1138 authors who have published 1381 publications receiving 7798 citations.

Cleaning Method Validation for Estimation of Dipyridamole Residue on the Surface of Drug Product Manufacturing Equipment Using Swab Sampling and by High Performance Liquid Chromatographic Technique.

Abstract: Objectives Cleaning validation is the procedure used to ensure that the cleaning process has eliminated the residues of drug substance from on the equipment surface after manufacture. A simple, sensitive, robust, and accurate high performance liquid chromatographic method was developed for the quantitative estimation of dipyridamole in swab samples obtained from the equipment surface after the manufacture of dipyridamole modified release capsules. Materials and Methods The method was developed by using a Hypersil BDS C18 (150×4.6 mm, 5 μm) column with mobile phase containing a mixture of buffer (potassium dihydrogen phosphate buffer, pH 7.0±0.05) and methanol in the ratio of 30:70 v/v. Flow rate was 1.5 mL/min, column temperature was 45°C, and injection volume was 5 μL. Results The method was validated and a specificity study was conducted to prove that there was no interference from blank and swab blank at the retention time of dipyridamole. The limit of detection and limit of quantification (LOQ) were established by using a series of linearity solutions and were found to be 0.041 μg/mL and 0.124 μg/mL, respectively. The method precision at the LOQ level was 8.6% relative standard deviation (RSD), method precision was 0.2% RSD, and ruggedness was 0.3% RSD. The method was accurate from the concentration of 0.13 μg/mL to 21.80 μg/mL and the recovery results met the acceptance criteria. The linearity of the method was found from 0.12 μg/mL to 20.14 μg/mL and the r2 value was 0.997. The robustness for the flow rate, wavelength, column temperature, buffer pH, and mobile phase ratio variations was tested, and all the system suitability parameters were met. Conclusion The method validation was performed as per the regulatory requirements and guidelines. The validation parameters met the acceptance criteria and the proposed method can be applied for the intended routine swab analysis.

Design of Modular Multilevel Converter for micro grid inked photovoltaic system

Abstract: This paper proposes a technique which employs two stage power conversion of output obtained from photovoltaic systems. In the present situation power generation from conventional sources needs to be reduced and it is more focused on non conventional sources. In this paper power generation from solar energy is emphasized. The array of photo-voltaic (PV) panels is connected to establish the dc link. DC link obtained from the PV array is input to DC-DC converter and the voltage obtained from converter is administered as input to modular multilevel converter. Depending upon the requirement the output is fed to the micro-grid or to the load. In order to increase the efficiency of entire PV generation system maximum power point tracking (MPPT) is employed. In addition to MPPT, control scheme has been introduced to escalate the performance of MMC. This paper presents an outcome of implementing Perturb & Observe (P&O) method along with hysteresis current controller for MMC. The performance of proposed system in PV environment is verified by simulation results and results are validated.

Synthesis and Antimicrobial Activity of 1-Aryl-4-(arylimino)-6-iminohexahydro-1,3,5-triazine-2-thione Derivatives

Abstract: A series of 6-imino-1-aryl-4-(arylimino)-1,3,5-triazinane-2-thione derivatives are synthesized by cyclization of 1-aryl-3-cyanoguanidine with aryl isothiocyante in the presence of sodium methoxide under MW irradiation. Structures of the synthesized compounds 3a-j are elucidated from 1H and 13C NMR, MS, and IR, data. The synthesized compounds are evaluated for their antimicrobial activity against B. subtilis, S. aureus, P. aeruginosa, and E. Coli. Some compounds demonstrate promising activity against the tested strains.