Background and importanceDifferent factors can influence the compatibility and stability of the mixture: drug type, concentration, solvent, container, temperature and light. There are some mixtures ...of drugs with proven stability, but there is a lack of evidence about the stability and compatibility of the combination of ondansetron and midazolam. The objective of this investigation was to study the compatibility and stability of a binary mixture of these drugs in solution for subcutaneous infusion in palliative careAim and objectivesTo evaluate the compatibility and stability of two admixtures of ondansetron and midazolam at two different temperatures (25°C and 37°C). The concentrations of the admixtures were 0.1 g/L–0.1 g/L and 0.5 g/L–1.0 g/L in NaCl 0.9% stored in elastomeric infusors protected from lightMaterial and methodsSamples were prepared and diluted in NaCl 0.9% in elastomeric infusors in triplicate to obtain four different conditions of concentration and/or storage temperature (0.1 g/L–0.1 g/L; 0.5 g/L–1.0 g/L for ondansetron and midazolam, respectively, stored at temperatures of 25°C and 37°C).The concentration of each drug was periodically determined using HPLC-UV and UV-Vis spectrophotometry methods in the analytical chemistry laboratory between February and June 2019. Conditions: C18 column, mobile phase methanol:KH2PO40.05 M, adjusted to pH 3 with H3PO3 (60:40, v/v) delivered at a flow rate of 1.0 mL/min. The sample injection volume was 20 μL, and triplicate injections were performed for every sample. The signal was recorded over 14 min and the retention times were 4.1 min for ondansetron and 7.8 min for midazolam. Ondansetron and midazolam concentrations were determined at 254 nm.ResultsHPLC-UV and UV-Vis spectrophotometric methods gave the same results. The stability of the admixtures diluted in NaCl 0.9% were as follow: ondansetron–midazolam (0.1 mg/mL–0.1 mg/mL and 0.5 mg/mL –1.0 mg/mL) were stable (retained >90% of their initial concentrations) for only 1 day at 25°C and 37°C, respectivelyConclusion and relevanceRecommended use is for a maximum of 1 day, at the concentrations evaluated; over time it tends to precipitate. Infuser conditioning decreases stability with respect to other conditioning materials, so other stability studies may not be extrapolated if stored under different conditions.References and/or acknowledgementsNo conflict of interest.
Ribavirin (RV) (1-β-D-ribofuranosyl-1,2,4-triazole-3-carboxamide), is a synthetic purine nucleoside analog with a broad spectrum of antiviral activity. To better understand the mechanism of action of ...RV, as well as its pharmacokinetic characteristics, an assay that can allow specific, sensitive, and accurate measurement of RV in biologic samples is critical. In this way, diverse analytical methods have been established. In this work, we have recompiled these methods with the aim to present the different options for the RV determination.
A flow injection (FI) system was used to develop an efficient on-line sorbent extraction preconcentration system for palladium by graphite furnace atomic absorption spectrometry (GFAAS). The ...investigated metal was preconcentrated on a microcolumn packed with 1,5-bis(di-2-pyridyl)methylene thiocarbohydrazide immobilized on silica gel (DPTH-gel). The palladium is eluted with 40
μl of HCl 4
M and directly introduced into the graphite furnace. The detection limit for palladium under the optimum conditions was 0.4
ng
ml
−1. This procedure was employed to determine palladium in different samples.
Derivative spectrophotometry is an analytical technique of great utility for extracting both qualitative and quantitative information from spectra composed of unresolved bands, and for eliminating ...the effect of baseline shifts and baseline tilts. It consists of calculating and plotting one of the mathematical derivatives of a spectral curve. Thus, the information content of a spectrum is presented in a potentially more useful form, offering a convenient solution to a number of analytical problems, such as resolution of multi-component systems, removal of sample turbidity, matrix background and enhancement of spectral details. Derivative spectrophotometry is now a reasonably priced standard feature of modern micro-computerized UV/Vis spectrophotometry.
The instrumental development and analytical applications of derivative UV/Vis regions absorption spectrophotometry produced in the last 10 years (since 1994) are reviewed.
Recently, a new and fast equilibrium-based solvent microextraction technique termed vortex-assisted liquid–liquid microextraction was developed. In this technique, the dispersion of the extraction ...solvent is enhanced by vortex mixing. The aim of the present review is to discuss the applications of vortex agitation in solvent-microextraction procedures.
Thalidomide, a racemate, is coming into clinical use as immuno-modulating and anti-inflammatory drug. Thalidomide was approved by the FDA in July 1998 for the treatment of erythema nodusum leprosum ...associated with leprosy. Recently, thalidomide is proving to be a promising drug in the treatment of a number of cancers and inflammatory diseases, such as multiple myeloma, inflammatory bowel disease (Crohn's disease), HIV and cancer associated cachexia. These effects may chiefly be exerted by
S-thalidomide, but the enantiomers are inter-converted in vivo. Thalidomide is given orally, although parenteral administration would be desirable in some clinical situations.
Thalidomide has been determined in formulations and, principally in biological fluids by a variety of methods such as high-performance liquid chromatography with ultraviolet detection and liquid chromatography coupled with tandem mass spectrometry. The overview includes the most relevant analytical methodologies used in its determination.
The present article reviews the methods of determination published for morphine and its metabolites covering the period from 1980 until at the first part of 2006. The overview includes the most ...relevant analytical determinations classified in the following two types: (1) non-chromatographic methods and (2) chromatographic methods.
Sertraline is a widely used antidepressant belonging to the selective serotonin reuptake inhibitor class; its efficacy has been demonstrated not only in the treatment of major depression, obsessive ...compulsive and panic disorders, but also for eating, premenstrual dysphoric and post-traumatic stress disorders.
Several methods have been published for the determination of sertraline in pharmaceuticals, biological materials and environmental samples. The purpose of the current review is to provide a systematic survey of the latest analytical techniques for the determination of sertraline covering the period from 1987 until 2008.
Selective sorption of Sb(III) on a microcolumn packed with 1,5-bis(di-2-pyridyl)methylene thiocarbohydrazide immobilized on silica gel (DPTH-gel) has been used for determination of Sb(III). A ...flow-injection system comprising a microcolumn connected to the tip of the autosampler was used for preconcentration. The sorbed antimony was eluted with nitric acid directly into the graphite furnace and determined by AAS. The detection limit for antimony under the optimum conditions was 0.3 ng mL(-1). This procedure was used for determination of antimony in natural water, soil, vegetation, and a certified sample of a city waste incineration ash (BCR 176).
Anthropogenic emission of platinum group elements (PGEs) from the abrasion of automotive catalytic converters into the environment has significantly increased. Dust emitted from the catalyst is ...causing pollution problems of these metals in the future. However, the concentration level of these PGEs is still very low in the nature. The choice of which determination method to use depends on the levels of rhodium, the nature of the sample matrix and the availability of the instrument. In recent years, the development of analytical methods for the determination of rhodium has increased. This review reports the developments in UV-vis absorption spectrometry applied to the determination of rhodium.
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