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Deepika Thakur,Amandeep Kaur,Suraj Sharma 한국약제학회 2017 Journal of Pharmaceutical Investigation Vol.47 No.3
The aim of the proposed study was to develop a novel sensitive and rugged stability indicating HPLC method based on an approach of fractional factorial design (FFD) for the simultaneous of estimation of gliclazide and metformin hydrochloride without prior separation in tablets. Preliminary experiments were conducted to identify the critical attribute factors and using Taguchi screening method to assess risk management method process parameters. Later on FFD was applied to optimize the resolution as response between both drugs in short run time. Sixteen experimental runs were performed from grid search data using design of expert software v.7.0. Furthermore, the optimized method was then validated according to the ICH guidelines. The generated model using FFD for the resolution was found to be highly statistically significant (p\0.05) and after analyzing the optimized zone within the design space, the final chromatographic conditions were selected as mobile phase 60:20:20:0.5, pH 7.5, flow rate 1.0 ml/min and column temperature 25 C using analytical column C18 Nucleosil ODS (250 9 4.6 mm2 i.d, 5 l) at 227 nm of detector wavelength. Validation of the developed method by QbD has manifested the specificity, accuracy and excellent linearity range and correlation values (R2) 0.997 and 0.996 for drugs. From the analysis it was measured that their LOD and LOQ values for the drugs were 0.035, 0.080 lg/ml and 0.40, 0.55 lg/ml. Therefore, a novel sensitive, accurate and stability indicating method was developed with high degree of practical utility of both drugs estimation in pharmaceutical dosage forms.
Deepika Thakur,Ashay Jain,Gargi Ghoshal,U. S. Shivhare,O. P. Katare 한국약제학회 2017 Journal of Pharmaceutical Investigation Vol.47 No.5
Anthocyanin has been proven to impart several health benefits and biological functions. Though, various analytical methods have been reported for single/multicomponent analysis of anthocyanins, found to be tedious, time consuming and difficult to reproduce. Analytical studies on specific anthocyanins for estimation using an approach of Analytical Quality by Design are scarce. USP method is only reliable for cyanidin-3-O-glucoside (CY-3- O-Glu) estimation, but exploring many disadvantage of having high buffer concentration in mobile phase system and gradient elution, hence column blockage. So there is need to develop a novel HPLC method to overcome this problem with the use organic solvents with lesser volume of buffer in isocratic mode of elution. The aim is to develop a robust and precise method for estimation of CY-3-O-Glu in biopolymer based microcapsules and tablets. The optimized method consisted of mobile phase containing solvent A and B, flow rate 0.8 mL/min with 20 min of analysis time. The method was further validated in accordance with current ICH guidelines Q2 (R1) and found to be highly selective for component in the presence of degradation products confirmed by Mass spectra. Therefore, the proposed method was found to be suitable for routine analysis of CY-3-O-Glu in food and pharmaceutical based formulations.
Thakur, Preeti,Chahar, Deepika,Thakur, Atul Techno-Press 2022 Advances in nano research Vol.12 No.4
Nickel substituted cobalt-zinc ferrite nanoparticles with composition Co<sub>0.5</sub>Zn<sub>0.5</sub>Ni<sub>x</sub>Fe<sub>2-x</sub>O<sub>4</sub> (x = 0.25, 0.5, 0.75, 1.0) were synthesized using a wet chemical method named citrate precursor method. Various characterizations of the prepared nanoferrites were done using X-ray powder diffractometry (XRD), Scanning electron microscopy (SEM), UV visible spectroscopy and Fourier transform spectroscopy technique (FT-IR). XRD confirmed the formation of cubic spinel structure of the samples with single phase having one characteristic peak at (311). The value of optical band gap (E<sub>g</sub>) was found to decrease with Ni substitution and have values in the range 2.30eV to 1.69eV. A Fenton-type system was created by photocatalytic activity using source of visible light for removal of methylene blue dye. Observations revealed increase in the degradation of methylene blue dye with increasing nickel content in the samples. The degradation percentage was increased from 77.32% for x = 0.25 to 90.16% for x = 1.0 in one hour under the irradiation of visible light. Also, the degradation process was found to have pseudo first order kinetics model. Hence, it can be observed that synthesized nickel doped cobalt-zinc ferrites have good capability for water purification and its degradation efficiency enhanced with increase in nickel concentration.
Deepika Thakur,Soonmin Seo,Jinho Hyun 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.123 No.-
Here we describe the fabrication of a three-dimensional triboelectric nanogenerator (TENG) with carboxymethylatedcellulose nanofiber (CM-CNF) and perfluoroalkoxy (PFA) films. The origami designedTENG of CM-CNF/PFA is compact, flexible and lightweight with improved durability. We highlight thedependence of output performance of the TENG upon functionalization of the CM-CNF film along withvarious loading force and frequencies. Carboxymethylation of the cellulose nanofiber directly increasesthe output voltage and current of the CM-CNF/PFA TENG. The designed TENG can produce a maximumof 2000 lWof output power at 10 MX of load resistance under 10 N of force at 2 Hz. The generated electricaloutput from the TENG is stored in a capacitor and used to power light-emitting diodes. The TENGdemonstrates an effective and portable system of functionalized CM-CNF films for energy harvesting withmore than 10,000 cyclic test, which confirms no loss in output performance.