Authors:A. Mohan, S. Dhayalamurthi, P. Anandan, and D. Saravanan
The present study reports the dissolution method for a novel fixed dose combination (FDC) containing etodolac (ET) and propranolol hydrochloride (PH) developed utilizing USP Apparatus 1 (basket) at 100 rpm with 1000 mL of phosphate buffer (pH 6.8; 0.05 M) medium at 37°C. An isocratic reversed-phase liquid chromatographic (RPLC) method was also developed for the simultaneous determination of ET and PH on an octadecylsilica column using phosphate buffer (pH 5.5) and acetonitrile (60:40, υ/υ) as the mobile phase with ultraviolet (UV) detection at 292 nm. Validation data were obtained, which demonstrated that the dissolution methodology is accurate, precise, linear, and rugged for the combination tablets.
Authors:R. Nandakumar, A. Saravanan, P. Singaram, and B. Chandrasekaran
Field experiments were conducted with rice (ADT-39) during the wet Kharif season (July- October 2001) at two locations, the Tamil Nadu Rice Research Institute (TRRI) farm, Aduthurai (Vertisol) and the Agricultural Research Station (ARS) farm, Pattukkottai (Alfisol), representing the old and new delta areas of the Cauvery, respectively. The same set of treatments was followed in both soils. The treatments consisted of the recommended NPK fertilizer application at 75% and 100% alone, and 10 or 20 kg ha-1 humic acid (HA) in combination with NPK fertilizers as soil application, besides an integrated method involving soil application, root dipping and foliar spraying with humic acid and NPK fertilizers. initial soil samples from the experimental fields were analysed for physical, physico-chemical and chemical properties. Surface soil samples were collected at critical growth stages and analysed for various available nutrients. The results of the field experiments revealed that the application of humic acid along with inorganic fertilizers led to higher soil nutrient availability at all the growth stages of rice. Similar results were obtained in both Vertisol and Alfisol. The present investigation concluded that the best treatment for soil nutrient availability was 10 kg ha-1 HA (soil application) + 0.1% HA foliar spray (twice) + 0.3% HA root dipping + 100% NPK, which was on par with the treatment involving 20 kg ha-1 HA (soil application) + 100% NPK compared to the other treatments.
Authors:Narendra A. Gajbhiye, Jayanti Makasana, Tushar Dhanani, and Raju Saravanan
Aegle marmelos Correa (Bael tree) is a medicinal fruit tree, widely used for healing purposes in various systems of medicines. Coumarins and alkaloids present in various parts of bael tree including roots and fruit pulp are the primary active constituents implicated for its biological activities. An efficient liquid chromatography–electrospray ionization—tandem mass spectrometry (LC—ESI—MS/MS) method was developed for identification and simultaneous determination of four coumarin derivatives, namely, umbelliferone, psoralene, marmin, and imperatorin, and an alkaloid, skimmianine, in root and stem bark of A. marmelos. The chromatographic separation of analytes was performed on Altima C18 (50 × 4.6 mm, 3 μm) column using methanol and 0.1% acetic acid in water (54:46, v/v) as the mobile phase under isocratic conditions. The LC–MS/MS parameters were optimized in the positive ionization mode using electrospray ionization source. The quantification of the analytes was performed using multiple reaction monitoring (MRM) transitions, umbelliferone (m/z 163.1 → 107.1), psoralene (m/z 187.2 → 131.1), marmin (m/z 333.5 → 163.2), imperatorin (m/z 271.1 → 203.1), and skimmianine (m/z 260.1 → 227.0). The extraction method was standardized for optimum yield of coumarin derivatives and the alkaloid in different extraction solvents. Higher yield of the analytes was found in methanolic extracts in comparisons to petroleum ether, chloroform, ethyl acetate, ethanol, and water. The method was validated for linear range, intra- and inter-batch precision and accuracy. The distribution of coumarin derivatives and an alkaloid was found to vary significantly in different plant samples, and their concentration was much higher in roots as compared to stem bark.