Chemoselective C-benzoylation of phenols by using AlCl3 under solvent-free conditions

Substituted phenols were chemo-selectively reacted with benzoylchloride in presence of aluminum chloride under solvent-free condition to afford the corresponding 2'-hydroxy aryl benzophenones in excellent yields (72-96%). Naphthol benzoylation resulted in lower yields as compared to phenols. Both reactions completed in 5-10 min with quantitative yields providing excellent control over regioselectivity of products. KEY WORDS: Chemoselective C-acylation, F-C reaction, Fries rearrangement Bull. Chem. Soc. Ethiop. 2015, 29(2), 319-325DOI: http://dx.doi.org/10.4314/bcse.v29i2.1

Taste masking of Metoclopramide Hydrochloride by Novel Melt Granulation

The purpose of this research was to mask the intensely bitter taste of metoclopramide HCl by complexation with glycerol monostearate. Drug- glycerol monostearate complex was prepared by melt granulation technique in the ratio of 1:1, 1:2, 1:3,1:4. The optimum drug: glycerol monostearate ratio required for complexation was determined. The drug: glycerol monostearate complex were evaluated for the drug content, in-vivo, in-vitro taste evaluation study. The complex was characterized by FTIR, differential scanning calorimetry. The taste evaluation depicted the successful taste masking of  metoclopramide HCl with drug: glycerol monostearate 1:4 ratio.

Comparative study of the thermoluminescence glow curves recorded from varieties of Vitis vinifera, V. labrusca and V. champini

Thermoluminescence (TL) glow curves were recorded from leaves of eight Vitis varieties grown in South-West India, viz. Thompson Seedless, Sonaka, Anab-E-Shahi, Kishmish Charni, Tas-A-Ganesh, Black Monuka, Bangalore Purple and American Dogridge belonging to the Vitis vinifera, V. labrusca and V. champini species. The TL peaks were analysed, using a computer-assisted model based on the general order kinetics theory, to determine thermodynamical parameters such as activation energy, entropy, frequency factor and free energy. It was observed that all six V. vinifera samples showed an entirely different TL pattern consisting of only one prominent and highly narrow peak at around -5 degrees C (peak II). The prominence of this peak attributed to S2/S3 Qa- recombination suggests a modification at the plastoquinone electron acceptor sites. On the other hand, the remaining two varieties Bangalore Purple and American Dogridge showed broader TL spectra consisting of a higher number of peaks. This basic difference is attributed to the difference in species of the selected varieties. Moreover, the TL recorded from Bangalore Purple resembled the standard TL spectra of spinach. The study undertaken in this paper may be relevant in grape breeding programs

Formulation and Characterization of Fexofenadine hydrochloride Fast Dissolving Tablet by using various Superdisintegrants

In the present work, fast dissolving tablets of fexofenadine HCl were designed with a view to enhance patient compliance by direct compression method. The present work studied the effect of superdisintegrants on release rate of fexofenadine HCl in the form of fast disintegrating tablet. For the present study range of superdisintegrants in their different concentrations, were used. The superdisintegrants used were crosscarmellose sodium, crosspovidone and kyron        T-314. The blends were prepared by direct compression technique. The tablets were evaluated for hardness, thickness, friability, drug content, weight variation and in-vitro drug release studies in pH 6.8. Keywords: Fexofenadine hydrochloride, fast dissolving tablets, crosscarmellose sodium, crospovidone, kyron T-31

Formulation Design and Optimization of Sustained Release Tablet of Ambroxol hydrochloride

A sustained release matrix formulation for Ambroxol hydrochloride was designed and developed to achieve a 12 h release profile. Using HPMC K15M and Eudragit RSPO as an inert matrix forming agent to control the release of Ambroxol hydrochloride. The matrix tablets for these formulations were prepared by direct compression and their in-vitro release tests were carried out for a period of 12 hours using USP dissolution test apparatus (type I- Basket) at       37±0.5°C and 100 rpm speed. A 32 full factorial design was used for optimization by taking the concentration of HPMC K15M (X1) and Eudragit RSPO (X2) were selected as independent variables, where as initial release at the 2 hrs (Y1, % drug release), release rate at the 8 hrs (Y2,   % drug release) and the concentration of Ambroxol hydrochloride released in 12 hrs (Y3, % drug release) were chosen as dependent variables. The optimized formulation F4 follows Hixon Croswell order release kinetics with non-Fickian diffusion mechanism. From the study, it was concluded that the release of Ambroxol hydrochloride can be effectively sustained using combination of HPMC K15M and Eudragit RSPO

A convenient method for lactonization of α-allyl esters using iodine in dimethyl- sulphoxide

A simple method for the synthesis of α-γ-disubstituted-γ-butyrolactones by cyclization of α-allyl esters using iodine in dimethylsulphoxide is reported. This method is efficient and operationally simple in comparison to methods using transition metal complexes. KEY WORDS: γ-Butyrolactones, α-Allyl esters, Iodine, Dimethyl sulphoxide Bull. Chem. Soc. Ethiop. 2014, 28(3), 469-473.DOI: http://dx.doi.org/10.4314/bcse.v28i3.1