G.S.N. Koteswara Rao’s scientific contributions

Aim: The leaves of the plant Tecomaria capensis were extracted with different solvents and screened for anti-inflammatory activity. Materials and Methods: The ethyl acetate extract of the plant T. capensis has showed the presence of flavonoids, glycosides, steroids, and terpenoids. Anti-inflammatory activity was investigated by carrageenan-induced method (in vivo) for isolated compounds from ethyl acetate extract of T. capensis leaves. Results and Discussion: The in vitro anti-inflammatory activity of the 3, 4 dihydro-2,2 dimethyl-2H-benzochromene-5,6 dione and (3R)-3,7-dimethyloct-6-en-1-ol was concentration dependent. While in in vivo, the percentage reduction in the paw volume calculated at 3 rd h for 3,4 dihydro-2,2 dimethyl-2H-benzochromene-5,6 dione was 54.5%, (3R)-3, 7-dimethyloct-6-en-1-ol was 77.3%, and standard diclofenac was 79.6%. Conclusion: This study demonstrates that isolated compounds of ethyl acetate extract of T. capensis have significant anti-inflammatory activities.

Aim: The leaves of the plant Tecomaria capensis were extracted with different solvents and screened for their analgesic activity. Materials and Methods: The ethyl acetate extract of the plant T. capensis has showed the presence of flavonoids, glycosides, steroids, and terpenoids. The analgesic activity of ethyl acetate extract of T. capensis leaves is evaluated by Eddy's hot plate and tail flick method. Results and Discussion: This study demonstrates that ethyl acetate extracts of T. capensis have significant analgesic activities. Further, with column chromatography technique, different compounds are isolated from the extract. Among the different compounds, 3, 7-dimethyloct-6-en-1-ol showed a comparable activity to standard. Conclusion: The present investigation indicates the probable use of T. capensis extracts in the evaluation of analgesic activity.

Aim and Objective: The main objective of the present research investigation is to formulate the sustained release (SR) formulation of rosuvastatin. Rosuvastatin, an antihyperlipidemic agent, belongs to Biopharmaceutical Classification System class-II agent. Materials and Methods: The SR tablets of rosuvastatin were prepared by employing different concentrations of hydroxy methyl propyl cellulose (HPMCK4M) and sodium carboxymethyl cellulose (SCMC) in different combinations by direct compression using 3 ² factorial designs. The concentration of polymers, HPMCK4M, and SCMC required to achieve the desired drug release was selected as independent variables, X 1 and X 2 , respectively, whereas time required for 10% of drug dissolution (t 10% ), 50% (t 50% ), 75% (t 75% ), and 90% (t 90% ) was selected as dependent variables. Results and Discussion: A total of nine formulations were designed and are evaluated for hardness, friability, thickness, % drug content, and in vitro drug release. From the results, it was concluded that all the formulations were found to be within the pharmacopeial limits and the in vitro dissolution profiles of all formulations were fitted into different kinetic models; the statistical parameters such as intercept, slope, and regression coefficient were calculated. Polynomial equations were developed for dependent variables. The validity of developed polynomial equations was verified by designing 2 check point formulations (C 1 and C 2 ). According to SUPAC guidelines, the formulation (F 4 ) containing 30 mg of HPMCK4M and 40 mg of SCMC is the most similar formulation (similarity factor f 2 = 89.561, dissimilarity factor f 1 = 1.543, and no significant difference, t = 0.0056) to marketed product (CRESTOR). Conclusion: The selected formulation (F 4 ) follows zero-order and Higuchi kinetics, and the mechanism of drug release was found to be non-Fickian Diffusion (n = 0.963).

Aim: Nimesulide is poorly water soluble (0.1 mg/ml). The low aqueous solubility gives difficulties in bioavailability. To improve the aqueous solubility and to enhance bioavailability the hydrotropic technique were used. Materials and Methods: In this research, hydrotropes such as ascorbic acid, sodium p-hydroxy benzoate, and sodium gentisate, and sodium ascorbate were used. Solid complexes of nimesulide and hydrotropes were prepared using coprecipitation method. The precipitates were amorphous in nature. In general, solid complexes can be characterized by techniques such as melting point, infrared-spectroscopy, differential scanning calorimetry, Fourier transformed infrared spectral studies were carried out for nimesulide and hydrotropes for their pure form and their complexes. Results and Discussion: A hydrotrope solubilizes hydrophobic part of nimesulide in aqueous solutions. In general, hydrotropes consists of both hydrophilic part and a hydrophobic part in which the hydrophobic part is very small to form immediate self-aggregation. Hydrotropy is one of the solubility enhancement techniques which improve solubility to many folds with use of hydrotropes. It is one of the recognized techniques available for resolving the solubility issue in nimesulide. Conclusion: The present work investigates the solubility enhancement and hence the bioavailability of the drug. The solubility of the drug can be increased by a variety of contemporary methods such as hydrotropic solubilization and solid dispersions. Hydrotrophy refers to a solubilization process, whereby the addition of large amounts of a second solute results in an increase in the aqueous solubility of a poorly soluble compound.