Extending Shelf-life of Different Cut-flowers under Cold Room Conditions

Uniform and healthy Rose cv. ‘Dutch'; Gerbera cv. ‘Lexington'; Gladiolus cv. ‘Top Secrate'; Tuberose cv. ‘Bizet' and Carnation cv. ‘Liberty' were used for the study in September 2016. Cut flowers were harvested at 7.00 am at proper stage, transported within 1.30 hours by AC car to the Agricultural Research Laboratory of Ecofrost Technologies Pvt. Ltd., Pune and then immediately prepared for post-harvest treatment and storage. The aim of this study was to determine the effectiveness of different storage conditions, i.e. room and cold storage conditions (10°C + 93 % RH) on the longevity of the cut flowers. The two treatments viz., holding flowers at room temperature (RT) (T1) and at cold room conditions (T2), were replicated twice. The result showed that keeping cut-flowers at cold storage in a holding-solution of tap water recorded the maximum storage-life (days) compared to room conditions

ENANTIOMERIC SEPARATION OF ETODOLAC IN A BULK DRUG SUBSTANCE BY REVERSE-PHASE CHIRAL LIQUID CHROMATOGRAPHY METHOD

Objective: To develop novel, simple and rapid enantiomeric separation of Etodolac by reverse-phase high-performance liquid chromatographic method as per ICH guidelines.Methods: The R-isomer and S-isomer were baseline resolved on a CHIRAL-AGP, (100 x 4.0 mm i. d, 5 mm) column using a mobile phase system containing 0.1 M sodium dihydrogen phosphate dihydrate pH 4.0 buffer: Isopropanol (85:15 v/v.) at detector wavelength 225 nm and column temperature 25 °C. The chromatographic resolutions between R-isomer and S-isomer were found three. The developed method was extensively validated according to ICH guidelines.Results: Good linearity was observed for R-isomer over the concentration range of 300–3000 ng/ml, with the linear regression (Correlation coefficient R = 0.999) and proved to be robust. The limit of detection and limit of quantification of R-isomer was found to be 300 and 900 ng/ml, respectively for 10 ml injection volume. The percentage recovery of R-isomer was ranged from 98.0 to 102.0 in bulk drug samples of Etodolac. Etodolac sample solution and mobile phase were found to be stable for at least 48 hours. The proposed method was found to be suitable and accurate for the quantitative determination of R-isomer in bulk drugs.Conclusion: A novel, simple and rapid enantiomeric separation of Etodolac by reverse-phase high-performance liquid chromatographic method was developed and validated as per ICH guidelines. The developed method can be used for the quantitative determination R-isomer in bulk drug materials in pharmaceutical industry.Â

SEPARATION AND DETERMINATION OF THE S-ISOMER OF (10-CAMPHORSULFONYL) OXAZIRIDINE IN A BULK DRUG SUBSTANCE BY NORMAL-PHASE LIQUID CHROMATOGRAPHY

Objective: To develop novel, simple and accurate enantiomeric separation of (10-Camphorsulfonyl) oxaziridine by normal-phase high-performance liquid chromatographic method as per ICH guidelines.Methods: The S-isomer and R-isomer of (10-Camphorsulfonyl) oxaziridine were baseline resolved on a Chiralcel OD-H (250 x 4.0 mm i. d, 5 mm) column using a mobile phase system containing n-Hexane: ethanol: trifluoroacetic acid (90:10:0.1 v/v/v.) at detector wavelength 210 nm and column temperature 30 °C. The chromatographic resolutions between S-isomer and R-isomer were found three. The developed method was extensively validated according to ICH guidelines.Results: Good linearity was observed for S-isomer over the concentration range of 900–9000 ng/ml, with the linear regression (Correlation coefficient R = 0.999) and proved to be robust. The limit of detection and limit of quantification of S-isomer was found to be 400 and 900 ng/ml, respectively for 20 ml injection volume. The percentage recovery of S-isomer was ranged from 97.0 to 102.0 in bulk drug samples of (10-Camphorsulfonyl) oxaziridine. (10-Camphorsulfonyl) oxaziridine sample solution and mobile, phase was found to be stable for at least 48 hours. The proposed method was found to be suitable and accurate for the quantitative determination of S-isomer in bulk drugs.Conclusion: A novel, simple and accurate normal phase LC method was described for the enantiomeric separation of 10-Camphorsulfonyl Oxaziridine is precise and specific.Â

STABILITY INDICATING HPLC METHOD FOR SIMULTANEOUS DETERMINATION OF OFLOXACIN AND FLAVOXATE HYDROCHLORIDE

Objective: The objective of this study was to develop and validate a stability indicating reverse-phase HPLC method for simultaneous estimation of Ofloxacin and Flavoxate hydrochloride from their combination product.Methods: The proposed RP-HPLC method was developed using inertsil C18, 5 µm, 250 mm × 4.6 mm column. The mobile phase used was a mixture of methanol and water in the proportion of 50:50 (v/v) with apparent pH adjusted to 4.9, and UV detection at 274 nm using a PDA detector and Empower-2 software. The flow rate was 1.0 ml/min. Ofloxacin, Flavoxate hydrochloride and their combination drug product were exposed to thermal, photolytic, hydrolytic, and oxidative stress conditions, and the stressed samples were analysed by the proposed method.Results: With the optimized method, retention times of Ofloxacin and Flavoxate hydrochloride were found to be 4.3 and 2.98 respectively. Peak homogeneity data of Ofloxacin and Flavoxate hydrochloride peaks obtained using PDA detector, in the stressed sample chromatograms demonstrated the specificity of the method for their estimation in the presence of degradants. The described method was linear over a range of 10-60 µg/ml with regression coefficient of 0.9996 and 0.9998. The mean recoveries were 99.57% and 99.99% for Ofloxacin and Flavoxate hydrochloride, respectively.Conclusion: Stress testing, which covered acid, alkali, peroxide, photolytic and thermal degradation was performed to prove the specificity of the proposed method and degradation, was achieved. The developed method was validated according to ICH guidelines and was found to be simple, precise and accurate with the prescribed values.Â

Spherical Casimir energies and Dedekind sums

Casimir energies on space-times having general lens spaces as their spatial sections are shown to be given in terms of generalised Dedekind sums related to Zagier's. These are evaluated explicitly in certain cases as functions of the order of the lens space. An easily implemented recursion approach is used.Comment: 18 pages, 2 figures, v2:typos corrected, inessential equation in Discussion altered. v3:typos corrected, 1 reference and comments added. v4:typos corrected. Ancillary results added in an appendi

TIRSPEC : TIFR Near Infrared Spectrometer and Imager

We describe the TIFR Near Infrared Spectrometer and Imager (TIRSPEC) designed and built in collaboration with M/s. Mauna Kea Infrared LLC, Hawaii, USA, now in operation on the side port of the 2-m Himalayan Chandra Telescope (HCT), Hanle (Ladakh), India at an altitude of 4500 meters above mean sea level. The TIRSPEC provides for various modes of operation which include photometry with broad and narrow band filters, spectrometry in single order mode with long slits of 300" length and different widths, with order sorter filters in the Y, J, H and K bands and a grism as the dispersing element as well as a cross dispersed mode to give a coverage of 1.0 to 2.5 microns at a resolving power R of ~1200. The TIRSPEC uses a Teledyne 1024 x 1024 pixel Hawaii-1 PACE array detector with a cutoff wavelength of 2.5 microns and on HCT, provides a field of view of 307" x 307" with a plate scale of 0.3"/pixel. The TIRSPEC was successfully commissioned in June 2013 and the subsequent characterization and astronomical observations are presented here. The TIRSPEC has been made available to the worldwide astronomical community for science observations from May 2014.Comment: 20 pages, 21 figures, 2 tables. Accepted for publication in Journal of Astronomical Instrumentatio

Evaluating thermogravimetric analysis for the measurement of drug loading in mesoporous silica nanoparticles (MSNs)

In this study, a thermogravimetric analysis (TGA) method for measuring the drug loading in mesoporous silica nanoparticles (MSNs) has been developed and evaluated in comparison with the drug loading quantification by high-performance liquid chromatography (HPLC). Indapamide was loaded into two different types of MSNs, namely Mobile Crystalline Material (MCM-41, pore size = 1.2 nm) and Santa Barbara Amorphous (SBA-15, pore size = 4.1 nm). Physical mixtures of the drug and silica gave a linear correlation between the observed and expected drug content for both TGA and HPLC, which were used for calibration purposes. The limit of detection (LOD) for the TGA method obtained from the physical mixture calibration curve was 0.77 % (w/w) and the r² value was 0.9936, whereas the HPLC had a LOD of 0.06 % (w/w) and an r² value of 0.9933. The sensitivity of the TGA method was well established using the drug loading studies, as it can detect the low loading of MCM-41 at 2.2 ± 0.21 % (w/w), compared to 5.1 ± 0.12 % (w/w) with the SBA-15. In all samples applied, the multiple comparison analysis showed an insignificant difference between the two methods (p > 0.05). The TGA data presented good evidence for using this technique as a sensitive, cost-effective, and low-variable quantitative analysis in the drug loading determination of the MSNs. TGA is not a selective method of quantification, but optimising the method using the pure and blank samples of MSNs and drug can significantly improve the sensitivity. This work provides a unique approach to apply TGA as a selective and more favourable method to characterise MSNs to do early formulation developments

DEVELOPMENT AND VALIDATION OF UV SPECTROPHOTOMETRIC METHODS FOR DETERMINATION OF MEGLUMINE IN BULK

UV, first, second and third derivative spectrophotometric methods have been developed for the determination of meglumine. The solutions of standard and sample were prepared in distilled water. For the first method i.e. calibration curve UV spectrophotometric method, the quantitative determination of the drug was carried at 254 nm and the linearity range was found to be 10 – 60 µg/ml. For the first, second, third derivative spectrophotometric methods the drug was determined at 247 nm, 216 nm, 266 nm with the linearity range 10 – 60 µg /ml. The calibration graphs constructed at their wavelength of determination were found to be linear for UV and derivative spectrophotometric methods. All the proposed methods have been extensively validated. There was no significant difference between the performance of the proposed methods regarding the mean values and standard deviations