Polarographic determination of EDTA in certain pharmaceutical dosage forms

A highly sensitive polarographic method was developed for the determination of EDTA added as a preservative in certain pharmaceutical preparations. The method involved chelation with Eu(III) followed by polarographic measurement of the chelate formed. A well-defined cathodic wave was developed in Britton–Robinson buffers over the pH range 2–12. The wave was characterized as being quasi-reversible and diffusion controlled. The current–concentration relationship was found to be rectilinear over the ranges 8–160 and 2–120 μg ml⁻¹, using DCt and DPP modes, respectively, with limit of detection of 0.1 μg ml⁻¹ using the DDP technique. The mechanism of the electrode reaction was verified. The proposed method was applied for the determination of EDTA in certain pharmaceutical dosage forms, and the results obtained were in agreement with those obtained by a reference method.     

Polarographic determination of flubendazole in spiked human urine and plasma

The voltammetric behavior of flubendazole was studied using direct current (DCt), differential pulse (DPP) and alternating current (ACt) polarography. The drug manifests a cathodic wave in 20% v/v formic acid solution. The wave was characterized as being irreversible, diffusion-controlled with limited adsorption properties. The diffusion current-concentration relationship was found to be rectilinear over the range 3.2-14.4 microg/ml and 0.1 to 12.8 microg/ml, using DCt and DPP modes, respectively, with minimum detectability of 0.161 microg/ml (5.14 x 10(-7) M) and 0.0.057 microg/ml (1.82 x 10(-8) M) using DCt and DPP modes, respectively. Furthermore, the proposed method was applied to the in-vitro determination of flubendazole in spiked human urine and plasma adopting the DPP technique. The percentage recoveries were 100.20+/-0.62 and 97.42+/-0.95, respectively.     

Spectrophotometric determination of fenoterol hydrobromide in pure form and dosage forms

A sensitive and rapid spectrophotometric procedure has been investigated for the determination of fenoterol either per se or in pharmaceutical preparations. The proposed procedure is based on the reaction between the drug and 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) at pH 7.2, using borate buffer, to produce a yellow adduct. The latter has maximum absorbance at 400 nm and obeys Beer's law within the concentration range 5-30 microg/ml. Regression analysis of the calibration data showed a good correlation coefficient (r=0.9996) with minimum detection limit of 0.24 microg/ml (6.2 x 10(-8) M). The proposed procedure has been successfully applied to the determination of this drug in its tablets and in syrup, the mean percent recoveries were 97.45+/-0.59 and 98.7+/-0.64%, respectively. The results obtained are in good agreement with those given using a reference method. The pharmaceutical additives other than active ingredient did not interfere. A proposal of the reaction pathway has been postulated.     

Spectrophotometric determination of propranolol in formulations via oxidative coupling with 3-methylbenzothiazoline-2-one hydrazone

A simple spectrophotometric method has been developed for the determination of propranolol hydrochloride in pure as well as in dosage forms. The method is based on the oxidative coupling reaction with 3-methylbenzothiazoline-2-one hydrazone. A mixture of an acidic solution of the chromogenic agent and the drug upon treatment with ceric ammonium sulfate produces an orange color peaking at 496 nm. The absorbance-calibration plot was linear over the range 1-10 microg/ml with minimum detectability (S/N=2) of 0.1 microg/ml (3.38x10(-7) M). The molar absorbitivity was 3.195x10(3) l/M/cm with correlation coefficient (n=10) of 0.9999. The different experimental parameters affecting the development and stability of the color were carefully studied and optimized. The proposed method was applied successfully to the determination of propranolol in its dosage forms. A proposal of the reaction pathway was presented.     

Safety evaluation of olive phenolic compounds as natural antioxidants

Free and total polyphenolic compounds were extracted from the fruits and leaves of the Picual cultivar. The safety limits of these compounds were recognized by measuring the activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and the levels of high-density lipoprotein (HDL) cholesterol and total lipids of rat serum. The free and total phenolic compounds (400, 800, and 1600 ppm) and butylated hydroxy toluene (BHT) (200 ppm) were daily ingested for 7 weeks. The administration of olive total and free phenolic compounds at 400 and 800 ppm did not cause any significant changes on ALT and AST activities and serum total lipids. These compounds at 1600 ppm caused significant increase in ALT and AST activities and the content of total lipids. Both olive phenolic compounds were superior to that of BHT in increasing HDL-cholesterol level. Nutritional experiments demonstrated that BHT at 200 ppm caused an enlargement in the kidney and liver of the rat compared with the administration of total and free olive phenolic compounds at 1200 and 1600 ppm. Microscopical examination of kidney and liver tissues of rats administered free and total phenolic compounds at 1200 ppm had the same histological character as that of control rats, while the administration of BHT (200 ppm) and phenolic compounds (1600 ppm) induced severe damage to the tissues of the rat kidney and liver.     

Basiliximab reduces the incidence of acute cellular rejection in live-related-donor kidney transplantation: a three-year prospective randomized trial

BACKGROUND: The aim of this work was to investigate the benefit of basiliximab induction therapy in living-related-donor kidney transplantation. METHODS: One hundred adult recipients of a first kidney allograft were randomized into two treatment groups, one to receive basiliximab and the second as a control. All patients received maintenance triple immunosuppressive therapy (steroids, cyclosporine microemulsion and azathioprine). The patients were followed up for a minimum of three years. The end points for evaluation included the incidence of acute rejection episodes, severity of rejection, cumulative steroid dose, patients' and graft survival. RESULTS: Basiliximab significantly reduced the proportion of patients who experienced an acute rejection in the first year (18/50) compared to the control group (31/50). At three years there were 26 acute rejections in the basiliximab group and 36 in control group. The cumulative steroid dose at three and 12 months was significantly lower in the basiliximab group. The overall incidence of post-transplant complications was comparable in the two groups. CONCLUSIONS: Prophylactic basiliximab is well tolerated and significantly reduces the incidence of acute rejection episodes in living-related-donor kidney transplantation.     

Square-wave adsorptive stripping voltammetric determination of danazol in capsules

Based on the interfacial adsorptive character of danazol onto the hanging mercury drop electrode (HMDE), a simple and sensitive square-wave adsorptive stripping voltammetric (SW-AdSV) procedure for the electrochemical analysis of this drug in pharmaceutical formulations has been developed and validated. Cyclic and SW-AdSV voltammograms showed a single well-defined irreversible cathodic peak. Various chemical and instrumental parameters affecting the monitored electroanalytical response were investigated and optimized for the danazol determination. Under these optimized conditions the SW-AdSV peak current showed a linear dependence on drug concentration over the range 7.5x10(-8)-3.75x10(-7) mol l-1 (r=0.999) with estimated detection limit (at a S/N ratio of 3) of 5.7x10(-9) mol l-1 (1.78 ng ml-1). A mean recovery of 100.9+/-1.2% and relative standard deviation of 1.07% were achieved. Possible interferences by substances usually present in the pharmaceutical tablets and formulations were also evaluated. The proposed electrochemical procedure was successfully applied for the determination of danazol in pharmaceutical capsules (Danol 100 mg) with mean recoveries of 100.48+/-0.87%. Results of the developed SW-AdSV method were comparable with those obtained by reported analytical procedures.     

Ethnic differences in herb and vitamin/mineral use in the elderly

BACKGROUND: Little information exists on herb and vitamin-mineral supplement use in very old people and whether use varies by ethnicity. OBJECTIVE: To examine the prevalence and predictors of herb and vitamin-mineral supplement use in a tri-ethnic sample of adults aged > or = 77 years. METHODS: In-home interviews in 1997-1998 assessed medications use and sociodemographic and health factors in community-dwelling elderly non-Hispanic white (n = 125), black (n = 112), and Hispanic (n = 128) adults. RESULTS: Of the 365 subjects (71.5% > or = 80 y old, 52.6% female), 172 reported using at least one of the preparations (vitamin-mineral supplements 132, herbs alone 21, both herbs and vitamin-mineral supplements 19). Herbal use varied by ethnicity: 12.8% in non-Hispanic whites, 16.1% in blacks, and 4.7% in Hispanics. The most commonly used herbs were garlic, Ginkgo biloba, saw palmetto, and vinegar. Use of vitamin-mineral supplements, alone or combined with herbs, also varied by ethnicity: 54.4% in non-Hispanic whites, 31.3% in blacks, and 37.5% in Hispanics. In the fully adjusted multivariate model with white ethnicity as reference, the odds ratio of vitamin-mineral supplements use for blacks was 0.37 (95% CI 0.21 to 0.65) and for Hispanics was 0.56 (95% CI 0.30 to 1.03). In bivariate analyses, female gender, black ethnicity, being born in the US, and having coronary artery disease were significantly associated with herbal use (p < 0.05); however, in the fully adjusted multivariate model, only the female gender remained significantly associated with herbal use (OR 2.14; 95% CI 1.00 to 4.59). CONCLUSIONS: Use of herbs or vitamin-mineral supplements is common in very old people and varies by ethnicity.     

RENAL EFFECTS OF RILMENIDINE IN VOLUME-LOADED ANAESTHETIZED DOGS

1. In anaesthetized, fluid expanded rats rilmenidine has diuretic and natriuretic effects. There is strong evidence that the natriuresis is mediated by putative imidazoline receptors. In contrast, in conscious euvolaemic dogs rilmenidine has a diuretic effect that is entirely attributable to activation of a₂-adrenoceptors, but no natriuretic effect. To determine whether the effects of rilmenidine are truly species dependent, or merely dependent upon the influences of anaesthesia and volume status, we tested the effects of rilmenidine in pentobarbitone anaesthetized, volume-loaded dogs. 2. The effects of rilmenidine in anaesthetized, volume-loaded dogs were similar to those found in conscious euvolaemic dogs. Compared with vehicle treatment, levels of glomerular filtration rate, urine flow and haematocrit were increased following rilmenidine treatment. No effect of rilmenidine on sodium excretion was observed. 3. We conclude that the renal responses to rilmenidine in dogs are largely unaffected by anaesthesia and plasma volume status. In particular, the natriuretic effect seen in rats was not observed. We conclude that putative imidazoline receptors do not have a major influence on sodium excretion in dogs.