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- Author or Editor: N. Jain x
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Some new organotin(IV) complexes with kojic acid and maltol
Synthesis, characterization and thermal studies
Abstract
Organotin(IV) complexes of kojic acid and maltol of the type R3Sn(L) and R2Sn(L)Cl [R=C6H5CH2-,p-ClC6H4CH2-; HL=kojic acid, maltol] have been synthesized in anhydrous THF. They were characterized by UV, IR,1H NMR, and mass spectral studies. Their activityvs. E. coli, S. aureus and P. pyocyanea bacterial strains have been studied and the general order of activity is S. auresu>P. pyocyanea>E. coli. In all the complexes, the ligand acts as bidentate, forming a five membered chelate ring. All the complexes are 1∶1 metal ligand complexes. Various thermodynamic parameters have been calculated for the first two decomposition steps using TG/DTA/DSC curves. (p-ClC6H4CH2)3Sn(L) complexes have the minimum and (C6H5CH2)2Sn(L)Cl complexes have the maximum activation energy.
Abstract
A method based on the complexometric titration of thorium using ethylene diaminetetra-acetic acid (EDTA) as complexant has been developed for the determination of thorium in thorium-plutonium solution without resorting to prior separation of plutonium. Plutonium in the form of Pu(VI) does not affect the thorium determination when present up to 10% in thorium—plutonium solution. For oxidation of plutonium to Pu(VI), HClO4 or AgO was used. HClO4 is preferred. The thorium values obtained without prior separation of plutonium are compared with those obtained after separating plutonium by anion exchange technique. A precision of ±0.5% has been obtained for 5–10 mg of thorium in the aliquot.
Abstract
Studies have been carried out on the solubility of Pu(III) oxalate by precipitation of Pu(III) oxalate from varying concentrations of HNO3/HCl (0.5–2.0M) solutions and also by equilibrating freshly prepared Pu(III) oxalate with solutions containing varying concentrations of HNO3/HCl, oxalic acid and ascorbic acid. Pu(III) solutions in HNO3 and HCl media were prepared by reduction of Pu(IV) with ascorbic acid. 0.01–0.10M ascorbic acid concentration in the aqueous solution was maintained as holding reductant. The solubility of Pu(III) oxalate was found to be a minimum in 0.5M–1M HNO3/HCl solutions containing 0.05M ascorbic acid and 0.2M excess oxalic acid in the supernatant.
Summary Amorphous content of a crystalline drug affects its physical and chemical properties as well as its performance. Consequently it is important to assess the extent of amorphous contents in pharmaceuticals. The present study utilizes the technique of solution calorimetry to quantify the percentage of crystallinity in samples of varying amorphous content in cefazolin sodium monohydrate, ceftriaxone sodium, cefotaxime sodium and cefoperazone sodium. Enthalpy of solution of 100% crystalline and amorphous drugs as well as their physical mixtures over the range 0-100 mass/mass% amorphous content were determined. As expected it has been found that amorphous forms have significantly higher energy than the corresponding crystalline form for all the drugs. Enthalpy of solution (Δsol H), an extensive thermodynamic property can provide a precise and unambiguous measure of the relative crystallinity provided amorphous and crystalline standards are appropriately chosen. A good correlation has been found between Δsol H and the amorphous contents of the drugs.
Summary
Fourteen samples of fresh curry leaves (Murraya Koenigii) were collected from 13 states of India and analyzed for 6 minor (Ca, Cl, K, Mg, Na and P) and 14 trace (Br, Ce, Co, Cr, Cs, Fe, Hg, Mn, Rb, Sb, Sc, Se Th and Zn) elements by 2-minute irradiation in a reactor followed by high resolution g-ray spectrometry. Peach Leaves (SRM-1547) and Mixed Polish Herbs (MPH-2) were used as comparator standards. Phosphorus was determined by counting the b-activity from 32P using an end-window GM counter. Most elements were found to vary in a wide range depending on their origin of location, e.g., Na (104-455 mg/g), K (10.3-30.3 mg/g), Ca (9.44-28.3 mg/g), Mg (1.14-7.19 mg/g), P (0.43-1.69 mg/g), Mn (24.8-63.0 mg/g), Fe (72.5-195 mg/g), Se (40.1-131 ng/g) and Zn (7.90-70.5 mg/g). Variation in the elemental concentrations of the same species of different origin may be attributed to ecological and geographical variations. Further, column and thin layer chromatography were used for separating three organic constituents from the ethanolic extract; 3-methylthiopropanenitrile; 1,2-benzenedicarboxylic acid, mono (2-ethylhexyl ester) and 1-penten-3-ol and characterized by IR and GC-MS. Inorganic elements may be present as complexes with the organic compounds.
Summary
A simple, selective, precise, and stability-indicating high-performance thinlayer chromatography (HPTLC) method for the analysis of ciprofibrate both in bulk drug and pharmaceutical formulation has been developed and validated. The method employed HPTLC aluminum plates precoated with silica gel 60 RP-18 F254 as the stationary phase. The solvent system consisted of methanol-water-triethylamine (2.8:2.2:0.2 υ/υ). The system was found to give compact spot for ciprofibrate (R F value of 0.55 ± 0.02). Densitometric analysis of ciprofibrate was carried out in the absorbance mode at 232 nm. The linear regression analysis data for the calibration plots showed good linear relationship with r 2 = 0.998 ± 0.0015 with respect to peak area in the concentration range 600–1600 ng per spot. The mean values ± SD of slope and intercept were 3.38 ± 1.47 and 986.9 ± 108.78, respectively, with respect to peak area. The method was validated for precision, recovery, and robustness. The limits of detection and quantification were 17.84 and 54.08 ng per spot, respectively. Ciprofibrate was subjected to acid and alkali hydrolysis, oxidation, and thermal degradation. The drug undergoes degradation under acidic and basic conditions. This indicates that the drug is susceptible to acid and base. The degraded product was well resolved from the pure drug with significantly different R F value. Statistical analysis proves that the method is repeatable, selective, and accurate for the estimation of investigated drug. The proposed developed HPTLC method can be applied for the identification and quantitative determination of ciprofibrate in bulk drug and pharmaceutical formulation.
