Stability, compatibility and plasticizer extraction of quinine injection added to infusion solutions and stored in polyvinyl chloride (PVC) containers.

The stability of quinine was determined in various diluents and in polyvinyl chloride (PVC) containers. The release of diethyhexyl phthalate (DEHP) from PVC bags into intravenous infusions of quinine was also measured. We used an injection of two doses of quinine; quiniforme at 500 mg and quinimax at 400 mg in either 250- or 500-ml PVC infusion bags containing 5% dextrose, to give initial nominal concentrations of 2 or 1 mg ml(-1) quiniforme and 1.6 or 0.8 mg ml(-1) quinimax, the mean concentrations commonly used in clinical practice. Samples were assayed by stability-indicating high-performance liquid chromatography (HPLC) and the clarity was determined visually. Experiments were conducted to determine whether the stability and compatibility of quinine would be compromised, and whether DEHP would be leached from PVC bags and PVC administration sets during storage and simulated infusion. There was no substantial loss of quiniforme and quinimax over 1- or 2-h simulated infusion irrespective of the diluent, and storage during 8 h at 22 degrees C, 48 or 72 h at 4 degrees C and 96 h at 45 degrees C. Leaching of DEHP was also detected during simulated infusion delivery using PVC bags and PVC administration sets. The quantity was less than 2 microg ml(-1). During storage at 4 degrees C and room temperature the leaching of DEHP was low, but when the temperature was 45 degrees C the quantity was high, 21 microg ml(-1). To minimise patient exposure to DEHP, quinine solutions with all drugs should be infused immediately or stored for a maximum of 48 h at 4 degrees C.

Determination of cyclohexamone after derivatization with 2,4-dinitrophenyl hydrazine in intravenous solutions stored in PVC bags by high performance liquid chromatography.

A high performance liquid chromatographic procedure is described for the determination of cyclohexanone leached in intravenous solutions from the poly(vinyl chloride) bags. After derivatization with 2,4-dinitrophenylhydrazine and extraction with pentane, the cyclohexanone derivative was analysed on a C18 BDS Hypersil column using mobile phase mixture of acetonitrile:water (55:45). Ultra-violet detection was performed at 368 nm. The limit of quantification was 30 ng/mL and the assay was linear from 0.05 to 50 micrograms/mL. The recovery was better than 95%. The proposed method is satisfactory in its accuracy and precision with particularly relative standard deviations (RSD) for intra-assay and inter-assay of below 10%. This method has been successfully used for the determination of cyclohexanone in aqueous solutions such as sodium chloride (0.9%) and glucose (5%) stored in PVC containers. The values obtained varied between 2.04 and 44.9 micrograms/mL according to solutions and volume.

Verapamil inhibits elastase release and superoxide anion production in human neutrophils.

In response to activation of phagocytic cells and during inflammatory disorders, some proteases and very reactive oxygen species are produced. These proteases and oxidants are involved in many diseases like tissue injury or atherosclerosis. We have shown in vitro that verapamil, a calcium channel blocker, had antielastase and antioxidant properties. This drug inhibited the release of elastase by neutrophils in a dose-dependent manner when these cells were stimulated by phorbol-myristate-acetate (PMA), by N-formyl-methionyl-leucylphenylalanine (fMLP) and by the calcium ionophore A23187 (Ca.I). In addition, verapamil inhibited superoxide anion when human neutrophils were stimulated by PMA, fMLP, dioctanoylglycerol (DiC8), Ca.I or by opsonised zymosan (OZ). Verapamil did not act by scavenging elastase or oxidants as demonstrated in cell-free models which showed no direct antielastase or antioxidant effect involved by verapamil. Superoxide anion and elastase inhibition by verapamil has been considered to the mobilization of cytosolic calcium and inhibition of protein kinase C. The results suggest that verapamil might contribute help the development and progression of atheroma where oxidants and elastase are involved.

Stability study of fotemustine in PVC infusion bags and sets under various conditions using a stability-indicating high-performance liquid chromatographic assay.

The stability and compatibility of fotemustine, a nitrosourea anticancer agent, in 5% dextrose solution with polyvinyl chloride (PVC) containers and administration sets were studied under different conditions of temperature and light. The drug was diluted to 0.8 and 2 mg ml(-1) in 100 or 250 ml 5% dextrose injection solutions for 1-h simulated infusions using PVC bags and administration sets with protection from light. After preparation in the PVC bags containing 5% dextrose, fotemustine was also prepared at the same concentrations and stored at 4 degrees C for 48 h and at room temperature (22 degrees C) or at sunray exposure ( > 30 degrees C) over 8 h with or without protection from light. The solution samples were removed immediately at various time points of simulated infusions and storage, and stored at -20 degrees C until analysis. The physical compatibility with PVC and chemical stability in solution of fotemustine were assessed by visual examination and by measuring the concentration of the drug in duplicate using a stability-indicating high-performance chromatographic assay. When admixed with a 5% dextrose solution, fotemustine 2 and 0.8 mg ml(-1) was compatible and stable over 1-h of simulated infusion using PVC bags through PVC administration sets with protection from light. On the other hand, in the same diluent, fotemustine was compatible and stable with PVC bags for at least 8 h at 22 degrees C with protection from light and for at least 48 h at 4 degrees C with protection from light. There were no pH variation, no visual change, no color change, no visible precipitation and no loss of the drug. Conversely, when the solutions were exposed to light (ambient or solar), the drug concentration decreased rapidly, leading to the production of a degradation product as shown by mass spectral analysis and a discoloration of the solutions. Finally, in all cases, no DEHP (di-2-ethylhexyl phthalate) was detected in the injection solution.

Involvement of the extracellular calcium in the release of elastase and the human neutrophils oxidative burst.

Some proteases (particularly elastase) and metabolites of very reactive oxygen species (superoxide anion, hydrogen peroxide, hypochlorous acid and hydroxyl radicals) are generated by polymorphonuclear neutrophils (PMNs) during inflammatory disorders. Divalent cations, especially calcium (Ca2+) play an important regulatory role in the different PMNs functions. The aim of this study is to determine the role of extracellular calcium during the liberation of elastase and of reactive oxygen species production by human PMNs. Consequently, in order to stimulate PMNs, phorbolmyristate acetate (PMA), formyl-methionyl-leucyl-phenylalanine (fMLP) and opsonized zymosan (OZ) have been used. PMNs stimulated by OZ did not release elastase to reverse the PMA and fMLP systems. The production of elastase by PMNs stimulated by PMA to reverse the fMLP system is independent from the extracellular calcium, between 0.0 and 1.5 mM. With various higher concentrations of calcium, varying from 1.5 to 4.0 mM, the release of elastase by PMNs stimulated by PMA is extracellular calcium-dependent to reverse the fMLP system. The superoxide anion (O2-) generated by PMNs activated by fMLP is dependent from the extracellular calcium in the medium, whereas O2- production by PMA or OZ stimulated neutrophils was extracellular calcium-independent. These observations suggest that an influx of calcium may play an important role in the production of elastase and in the capacity of PMNs stimulated by fMLP to produce O2- to reverse the PMA and OZ systems.

Effects of calcium antagonist diltiazem on leukocyte elastase and on reactive oxygen species production in human neutrophils.

During inflammatory disorders, some proteases and very reactive oxygen metabolites are produced by activated phagocytic cells. These proteases and oxidants are involved in many diseases like tissue injury or atherosclerosis. It was shown in vitro that diltiazem, a calcium channel blocker, had antielastase and antioxidant properties. This drug inhibited the release of elastase by neutrophils in a dose dependent manner when these cells were stimulated by phorbol-myristate-acetate (PMA) or by formyl-methionyl-leucylphenylalanine (fMLP) with an IC50 of 144.5 microM, and 132.8 microM, respectively. Towards the oxidants, the 50% inhibitory concentrations (IC50) of diltiazem are 422 microM, 138 microM and 165 microM for superoxide anion, hypochlorous acid and hydroxyl radical production by PMA stimulated human neutrophils, respectively. In the case of fMLP stimulated human neutrophils, the IC50 for superoxide anion is 78 microM. When human neutrophils were stimulated by dioctanoylglycerol (DiC8) or by calcium ionophore (Ca.I), the IC50 for superoxide anion were 175.5 microM and 186 microM, respectively. When human neutrophils were stimulated by opsonized zymosan (OZ), diltiazem did not show an inhibition of superoxide production in a dose dependent manner. This drug did not act by scavenging elastase or oxidants as demonstrated by cell free models. A mechanism of elastase and oxygen metabolites inhibition by diltiazem has been considered specially toward the mobilization of cytosolic calcium and an inhibition of protein kinase C cannot be excluded. The results suggest that diltiazem might contribute to attenuate the development and the progression of atheroma where oxidants and elastase have been implicated.