The Experts below are selected from a list of 231 Experts worldwide ranked by ideXlab platform
Arnold G Fogg - One of the best experts on this subject based on the ideXlab platform.
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use of solid phase extraction cartridges with differential pulse cathodic stripping voltammetry at a hanging mercury drop electrode determination of nedocromil sodium and pentamidine Isethionate in urine
Analyst, 1995Co-Authors: Maria Valnice Boldrin Zanoni, Josino Costa Moreira, Arnold G FoggAbstract:Nedocromil sodium (an antiasthma drug) and pentamidine Isethionate (an antiprotozoal agent) were determined in urine by cathodic stripping voltammetry after adsorptive accumulation at a hanging mercury drop electrode as examples of the use of solid-phase extraction cartridges with this technique. Prior separation from matrix interferents was necessary and this was carried out using either a C18 solid-phase extraction cartridge or liquid–liquid extraction. For nedocromil, a recovery of 100.5 ± 6.5%(± 2 standard deviations) was obtained from urine spiked with 0.42 µg ml–1 of the drug using a C18 cartridge (five determinations). A 97% recovery of pentamidine Isethionate was obtained by solid-phase extraction when the drug was added to urine at a level of 1.48 µg ml–1. At lower levels of pentamidine Isethionate, better recovery was obtained using liquid–liquid extraction: recoveries of between 60 and 100% were obtained at levels of 0.04–29.6 µg ml–1. Linear calibration graphs were obtained for the determination of both drugs at concentration levels in the measured solution lower than 1 × 10–7 mol l–1(i.e., less than approximately 0.05 µg ml–1): standard additions method was preferred for quantification. Relative standard deviations of 4.5% for the determination of pentamidine Isethionate and of 5.2% for the determination of nedocromil (n= 5) were obtained for urine samples containing 2.96 µg ml–1 of pentamidine Isethionate and 0.42 µg ml–1 of nedocromil.
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electrochemical reduction at mercury electrodes and differential pulse polarographic determination of pentamidine Isethionate
Analyst, 1993Co-Authors: Valnice M B Zanoni, Arnold G FoggAbstract:Reduction processes are observed for pentamidine Isethionate at a dropping mercury electrode above pH 7: the reduction potential is independent of pH below about pH 10. Below pH 10, adsorption of the reduced species is observed, whereas above pH 10 there is a large contribution owing to adsorption of pentamidine Isethionate. For the polarographic determination of pentamidine Isethionate, a pH of 8–9 is recommended with the addition of Triton X-100 as a maximum suppressor. Pentamidine Isethionate can be determined by differential-pulse polarography down to about 5 × 10–6 mol l–1.
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cathodic stripping voltammetric determination of pentamidine Isethionate at a hanging mercury drop electrode
Analyst, 1993Co-Authors: Valnice M B Zanoni, Arnold G FoggAbstract:Differential-pulse cathodic stripping voltammetry was used for the determination of trace amounts of pentamidine Isethionate at a hanging mercury drop electrode using its reduction peak at –1.57 V in 0.2 mol l–1 sodium hydroxide. The optimum accumulation potential and accumulation time were –1.1 V and up to 180 s, respectively. Linear calibration graphs were obtained up to 1 × 10–6 mol l–1: the limit of detection was calculated to be 3.0 × 10–10 mol l–1. The effect of various components of urine on the voltammetric response was studied, and albumin, creatinine and uric acid caused interference in the method. The direct determination of the drug (>1 × 10–7 mol l–1) in urine can be effected using a high dilution of the sample.
K M G Taylor - One of the best experts on this subject based on the ideXlab platform.
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manipulating the temperature of pentamidine Isethionate solutions in jet nebulisers
International Journal of Pharmaceutics, 1993Co-Authors: I Stelliou, G Venthoye, K M G TaylorAbstract:Abstract The effects of changes in the initial solution temperature and local environmental temperature on the temperature of pentamidine Isethionate solutions atomized in a jet nebuliser commonly employed for pentamidine therapy have been studied. In all cases the temperature of liquid decreased during atomization, but an initial solution temperature of 30°C or greater, with or without the nebuliser being held at constant temperature maintained the liquid in the nebuliser at a temperature likely to ensure that the drug remained in solution. Hand-holding the nebuliser during use at ambient temperature raised the temperature of the solution in the nebuliser by less than 3°C.
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ultrasonic nebulisation of pentamidine Isethionate
International Journal of Pharmaceutics, 1993Co-Authors: K M G Taylor, C HoareAbstract:Abstract The properties of pentamidine Isethionate aerosols produced by an ultrasonic nebuliser frequently used in clinical practice have been investigated. The mass median diameter of the aerosols was initially 5.1−5.6 μm, depending on the volume of solution atomized and the output setting of the nebuliser. The aerosol size tended to decrease, and the solution temperature increase with time. Between 57 and 74% of drug placed in the nebuliser was delivered during use, the remainder being associated with the device.
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pentamidine Isethionate delivery from jet nebulisers
International Journal of Pharmaceutics, 1992Co-Authors: K M G Taylor, G Venthoye, A ChawlaAbstract:Abstract This study has investigated the properties of aerosols of pentamidine Isethionate produced by two jet nebulisers commonly used in clinical practice. The size characteristics of the emitted aerosols varied throughout the time that drug solutions were nebulised, particularly at low gas flow rates. The aqueous solubility of pentamidine Isethionate was found to be highly temperature dependent. As the temperature of solutions within the nebulisers decreased by up to 13°C, recrystallization of drug occurred. Approx. 50% of drug available in the nebuliser was available for delivery from the nebulisers, the remainder being associated with the devices.
David Harbottle - One of the best experts on this subject based on the ideXlab platform.
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assessment of the thermal degradation of sodium lauroyl Isethionate using predictive isoconversional kinetics and a temperature resolved analysis of evolved gases
Industrial & Engineering Chemistry Research, 2019Co-Authors: Mohammed I Jeraal, Kevin J Roberts, Ian Mcrobbie, David HarbottleAbstract:Sodium lauroyl Isethionate is a popular, milder alternative to traditional soaps and surfactants in personal care formulations. Product performance, efficiency, color, and odor, however, can be compromised by thermal degradation at elevated manufacturing temperatures. Prediction of isothermal degradation rates in both air and N2 for a range of process conditions are determined using the Friedman isoconversional method. The thermal degradation levels in air are found to be 28 times higher than those in N2 over 5 h at 240 °C. Manufacturing under inert conditions, with maximum temperatures of 250 °C, is therefore necessary to avoid degradation levels significantly greater than 1 wt %. Using TGA-FTIR, the evolved gases from the degradation of sodium lauroyl Isethionate are identified to be water, carbon dioxide, carbon disulfide, sulfur dioxide, as well as alkyl and carbonyl species. The ensuing temperature-dependent analysis can be used to minimize evolution of undesirable or hazardous gases in Isethionate m...
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process focused synthesis crystallization and physicochemical characterization of sodium lauroyl Isethionate
ACS Sustainable Chemistry & Engineering, 2017Co-Authors: Mohammed I Jeraal, Kevin J Roberts, Ian Mcrobbie, David HarbottleAbstract:There is a notable lack of published data concerning sodium cocoyl Isethionate despite widespread application in the personal care industry. A specific homologue, sodium lauroyl Isethionate (SLI), was therefore synthesized, purified by recrystallization, and then subjected to a detailed physicochemical examination. A purity of 98% was achieved via repeat recrystallization in methanol. A turbidimetric solubility analysis was then executed to identify both its crystallizability and metastable zone width as a function of temperature. Thermogravimetric analysis yielded decomposition onsets of 330 °C for the purified SLI. A dynamic vapor sorption study also demonstrated reversibility in the 2.3% mass gained when it was exposed to sustained humidity of 87%. Surface tension measurements of purified SLI yielded a critical micellar concentration (CMC) of 5.4 mM and a plateau surface tension of 38 mN/m at 20 °C. Both values are lower than the previously reported values for SLI in water, thus indicating the performa...
Valnice M B Zanoni - One of the best experts on this subject based on the ideXlab platform.
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electrochemical reduction at mercury electrodes and differential pulse polarographic determination of pentamidine Isethionate
Analyst, 1993Co-Authors: Valnice M B Zanoni, Arnold G FoggAbstract:Reduction processes are observed for pentamidine Isethionate at a dropping mercury electrode above pH 7: the reduction potential is independent of pH below about pH 10. Below pH 10, adsorption of the reduced species is observed, whereas above pH 10 there is a large contribution owing to adsorption of pentamidine Isethionate. For the polarographic determination of pentamidine Isethionate, a pH of 8–9 is recommended with the addition of Triton X-100 as a maximum suppressor. Pentamidine Isethionate can be determined by differential-pulse polarography down to about 5 × 10–6 mol l–1.
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cathodic stripping voltammetric determination of pentamidine Isethionate at a hanging mercury drop electrode
Analyst, 1993Co-Authors: Valnice M B Zanoni, Arnold G FoggAbstract:Differential-pulse cathodic stripping voltammetry was used for the determination of trace amounts of pentamidine Isethionate at a hanging mercury drop electrode using its reduction peak at –1.57 V in 0.2 mol l–1 sodium hydroxide. The optimum accumulation potential and accumulation time were –1.1 V and up to 180 s, respectively. Linear calibration graphs were obtained up to 1 × 10–6 mol l–1: the limit of detection was calculated to be 3.0 × 10–10 mol l–1. The effect of various components of urine on the voltammetric response was studied, and albumin, creatinine and uric acid caused interference in the method. The direct determination of the drug (>1 × 10–7 mol l–1) in urine can be effected using a high dilution of the sample.
Henry J C De Vries - One of the best experts on this subject based on the ideXlab platform.
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randomized single blinded non inferiority trial of 7 mg kg pentamidine Isethionate versus 4 mg kg pentamidine Isethionate for cutaneous leishmaniaisis in suriname
PLOS Neglected Tropical Diseases, 2015Co-Authors: Ricardo V P F Hu, Masja Straetemans, Alida D Kent, Leslie O A Sabajo, Henry J C De VriesAbstract:Standard treatment of cutaneous leishmaniasis (CL) in Suriname entails three injections of pentamidine Isethionate (PI) 4 mg/kg per injection in 7 days (7 day regimen). Compliance to treatment is low and may contribute to increasing therapy failure. A 3 day regimen, including 2 injections of 7 mg/kg in 3 days may increase compliance. In a randomized, single-blinded non-inferiority trial conducted in Suriname, 84 CL patients received the 7 day regimen and 79 CL patients received the 3 day regimen. Primary objective was the proportion of patients clinically cured at 6 weeks follow-up. Secondary objectives were clinical cure at 12 weeks follow-up; parasitological cure at 6 and 12 weeks; adverse and drug related toxicity events recorded one week after the end of treatment and health related quality of life. The non-inferiority margin was set at 15%, 1 sided test, α = 0.1. At 6 weeks follow-up 31 (39%) patients in the 3 day regimen and 41 (49%) patients in the 7 day regimen were clinically cured. Intention to treat (ITT) analyses showed that the difference in proportion clinically cured was -9.6% (90% Confidence Interval (CI): -22.3% to 3.2%). Per protocol (PP) analysis showed that the difference in proportion clinically cured was 0.2% (90% CI: -14.6% to 15.2%). ITT analysis showed that the difference in proportion parasitological cured at 6 weeks was -15.2% (90% CI:-28.0% to -2.5%). PP analyses showed similar results. Non-inferiority could not be concluded for all adverse and toxicological events. We cannot conclude that the 3 day regimen is non-inferior to the 7 day regimen regarding proportion clinically and parasitological cured. Therefore there is no evidence to change the current standard practice of the 7 day regimen for the treatment of CL in Suriname
