Development and validation of a microbiological assay by turbidimetry to determine the potency of cefazolin sodium in the lyophilized powder form

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Validation of analytical methodology for quantification of cefazolin sodium pharmaceutical dosage form by high performance liquid chromatography to be applied for quality control in pharmaceutical industry

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Validation of analytical methodology for quantification of cefazolin sodium by liquid chromatography

A reversed-phase high performance liquid chromatography method was validated for the determination of cefazolin sodium in lyophilized powder for solution for injection to be applied for quality control in pharmaceutical industry. The liquid chromatography method was conducted on a Zorbax Eclipse Plus C18 column (250 x 4.6 mm, 5 μm), maintained at room temperature. The mobile phase consisted of purified water: acetonitrile (60: 40 v/v), adjusted to pH 8 with triethylamine. The flow rate was of 0.5 mL min-1 and effluents were monitored at 270 nm. The retention time for cefazolin sodium was 3.6 min. The method proved to be linear (r2 =0.9999) over the concentration range of 30-80 µg mL-1. The selectivity of the method was proven through degradation studies. The method demonstrated satisfactory results for precision, accuracy, limits of detection and quantitation. The robustness of this method was evaluated using the Plackett–Burman fractional factorial experimental design with a matrix of 15 experiments and the statistical treatment proposed by Youden and Steiner. Finally, the proposed method could be also an advantageous option for the analysis of cefazolin sodium, contributing to improve the quality control and to assure the therapeutic efficacy

Validation of cefazolin sodium by UV-spectrophotometric method

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Methods for qualitative analysis of cefazolin sodium raw material and pharmaceutical product

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Análise químico-farmacêutica de cefazolina sódica em pó liofilizado para solução injetável

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Sodium 2-nitrocinnamate dihydrate: a one-dimensional hydrogen-bonded coordination polymer

The title compound catena-poly[aqua-mu3-2-nitrocinnamato], [Na(C9H6NO4)(H2O)2]n, the sodium salt of trans-2-nitrocinnamic acid, is a one-dimensional coordination polymer based on six-coordinate octahedral NaO6 centres comprising three facially-related monodentate carboxylate O-atom donors from separate ligands (all bridging)[Na-O, 2.4370(13)-2.5046(13)A] and three water molecules (two bridging, one monodentate) [Na-O, 2.3782(13)-2.4404(17)A]. The structure is also stabilized by intra-chain water-O-H...O(carboxylate) and O-H...O(nitro) hydrogen bonds.

Fluorescence spectrometric study on the interactions of isoprocarb and sodium 2-isopropylphenate with bovine serum albumin

The binding interaction of the pesticide Isoprocarb and its degradation product, sodium 2-isopropylphenate, with bovine serum albumin (BSA) was studied by spectrofluorimetry under simulated physiological conditions. Both Isoprocarb and sodium 2-isopropylphenate quenched the intrinsic fluorescence of BSA. This quenching proceeded via a static mechanism. The thermodynamic parameters (ΔH°, ΔS° and ΔG°) obtained from the fluorescence data measured at two different temperatures showed that the binding of Isoprocarb to BSA involved hydrogen bonds and that of sodium 2-isopropylphenate to BSA involved hydrophobic and electrostatic interactions. Synchronous fluorescence spectroscopy of the interaction of BSA with either Isoprocarb or sodium 2-isopropylphenate showed that the molecular structure of the BSA was changed significantly, which is consistent with the known toxicity of the pesticide, i.e., the protein is denatured. The sodium 2-isopropylphenate, was estimated to be about 4–5 times more toxic than its parent, Isoprocarb. Synchronous fluorescence spectroscopy and the resolution of the three-way excitation–emission fluorescence spectra by the PARAFAC method extracted the relative concentration profiles of BSA, Isoprocab and sodium 2-isopropylphenate as a function of the added sodium 2-isopropylphenate. These profiles showed that the degradation product, sodium 2-isopropylphenate, displaced the pesticide in a competitive reaction with the BSA protein.

Thermoanalytical studies of natural potassium, sodium and ammonium alunites

Dynamic and controlled rate thermal analysis (CRTA) has been used to characterise alunites of formula [M(Al)3(SO4)2(OH)6 ] where M+ is the cations K+, Na+ or NH4+. Thermal decomposition occurs in a series of steps. (a) dehydration, (b) well defined dehydroxylation and (c) desulphation. CRTA offers a better resolution and a more detailed interpretation of water formation processes via approaching equilibrium conditions of decomposition through the elimination of the slow transfer of heat to the sample as a controlling parameter on the process of decomposition. Constant-rate decomposition processes of water formation reveal the subtle nature of dehydration and dehydroxylation.

Low sodium haemodialysis reduces interdialytic fluid consumption but paradoxically increases post-dialysis thirst

Background Interdialytic weight gain (IDWG) can be reduced by lowering the dialysate sodium concentration ([Na]) in haemodialysis patients. It has been assumed that this is because thirst is reduced, although this has been difficult to prove. We compared thirst patterns in stable haemodialysis patients with high and low IDWG using a novel technique and compared the effect of low sodium dialysis (LSD) with normal sodium dialysis (NSD). Methods Eight patients with initial high IDWG and seven with low IDWG completed hourly visual analogue ratings of thirst using a modified palmtop computer during the dialysis day and the interdialytic day. The dialysate [Na] was progressively reduced by up to 5 mmol/l over five treatments. Dialysis continued at the lowest attained [Na] for 2 weeks and the measurements were repeated. The dialysate [Na] then returned to baseline and the process was repeated. Results Baseline interdialytic day mean thirst was higher than the dialysis day mean for the high IDWG group (49.9±14.0 vs 36.2±16.6) and higher than the low weight gain group (49.9±14.0 vs 34.1±14.6). This trend persisted on LSD, but there was a pronounced increase in post-dialysis thirst scores for both groups (high IDWG: 46±13 vs 30±21; low IDWG: 48±24 vs 33±18). The high IDWG group demonstrated lower IDWG during LSD than NSD (2.23±0.98 vs 2.86±0.38 kg; P<0.05). Conclusions Our results indicate that patients with high IDWG experience more intense feelings of thirst on the interdialytic day. LSD reduces their IDWG, but paradoxically increases thirst in the immediate post-dialysis period.

Sodium removal from Maramarua CSG waters using Ngakuru zeolites

Coal seam gas (CSG) waters are a by-product of natural gas extraction from un derground coal seams. The main issue with these waters is their elevated sodium content, which in conjunction with their low calcium and magnesium concentrations can generate soil infiltration problems in the long run , as well as short term toxicity effects in plants due to the sodium ion itself. Zeolites are minerals having a porous structure, crystalline characteristics, and an alumino-silicate configuration resulting in an overall negative charge which is balanced by loosely held cations. In New Zealand, Ngakuru zeolites have been mined for commercial use in wastewater treatment applications, cosmetics, and pet litter. This research focuses on assessing the capacity of Ngakuru zeolites to reduce sodium concentrations of CSG waters from Maramarua. Batch and column test (flow through) experiments revealed that Ngakuru zeolites are capable of sorbing sodium cations from concentrated solutions of sodium. In b atch tests, the sodium adsorption capacity ranged from 5.0 to 34.3meq/100g depending on the solution concentration and on the number of times the zeolite had been regenerated. Regeneration with CaCl2 was foun d to be effective. The calculated sodium adsorption capacity of Ngakuru zeolites under flow-through conditions ranged from 11 to 42meq/100g depending on the strength of the solution being treated and on w hether the zeolites had been previously regenerated. The slow kinetics and low cost of the zeolities, coupled with potentially remote sites for gas extraction, could make semi-batch operational processes without regeneration more favourable than in more industrial ion exchange situations.

Sodium niobate adsorbents doped with tantalum (TaV) for the removal of bivalence radioactive ions in waste waters

Sodium niobates doped with different amount of tantalum (TaV) were prepared via thermal reaction process. It was found pure nanofibril and bar-like solids can be obtained when tantalum was introduced into the reaction system. For the well-crystallized fibril solids, the Na+ ions are difficult to be exchanged, and the radioactive ions such as Sr2+ and Ra2+ ions just deposit on the surface of the fibers during the sorption process, resulting in lower sorption capacity and distribution coefficients (Kd)`. However, the bar-like solids are poorly-crystallized and have lots of exchangeable Na+ ions. They are able to remove highly hazardous bivalent radioactive isotopes such as Sr2+ and Ra2+ ions. Even in the presence of lots of Na+ ions, they also have higher Kd. More importantly, such sorption finally intelligently triggers considerable collapse of the structure, resulting in the entrapment of the toxic bivalent cations permanently in the solids so that they can be safely disposed. This study highlights new opportunities for the preparation of Nb-based adsorbents to efficiently remove the toxic radioactive ions from contaminated water.