sulindac and tiaprofenic-acid

Topics: Anti-Inflammatory Agents; Arthritis; Aspirin; Diclofenac; Humans; Ibuprofen; Indomethacin; Naproxen; Phenylbutazone; Phenylbutyrates; Piroxicam; Propionates; Sulindac; Thiazines

Poly(ethylene glycol) (PEG)-coated capillaries exhibit unique properties in nonaqueous electrolytes. Immobilized PEG interacts significantly with different cations present in nonaqueous electrolytes. This can induce a positive surface charge on PEG-coated capillaries and results in an adjustable anodic electroosmotic flow (EOF) in nonaqueous electrolytes whereas a reduced cathodic EOF is observed in aqueous electrolytes. The EOF can reversibly be adjusted by the variation of the electrolyte constitution, namely the type of the solvent used and the nature and concentration of background cations. In methanol and especially in acetonitrile electrolytes the magnitude and also the direction of EOF is strongly dependent on the water content. Using different alkali metal cations, the EOF can be increased, reduced, or even reversed depending on the nature of the cation. The directed manipulation of EOF in methanolic electrolytes using PEG-coated capillaries was applied for optimization of nonaqueous capillary electrophoretic separations of acidic compounds with regard to reproducibility, resolution, and analysis time.

Topics: Acetonitriles; Benzoic Acid; Buffers; Chemical Phenomena; Chemistry, Physical; Electrolytes; Electrophoresis, Capillary; Flurbiprofen; Ibuprofen; Methanol; Osmosis; Phenylacetates; Polyethylene Glycols; Propionates; Reproducibility of Results; Salicylic Acid; Silicon Dioxide; Solvents; Sulindac; Surface Properties; Water

The potential utility of capillary zone electrophoresis (CZE) for the separation and quantitative determination of some non-steroidal anti-inflammatory drugs (NSAIDs) was investigated. The influence of different parameters on migration times, peak symmetry, efficiency and resolution was studied; these parameters included the nature and concentration of the anionic and cationic components of the separation buffer. A buffer consisting of 75 mM glycine adjusted to pH 9.1 with triethanolamine was found to provide a very efficient and stable electrophoretic system for the CZE analysis of NSAIDs, giving RSD values of about 0.1 and 0.5% for the within-day reproducibility of migration times and peak areas, respectively at a concentration of 25 micrograms ml-1 (n = 5). Response was linear from 2-100 micrograms ml-1 for both sulindac and tiaprofenic acid, for which the LOQ values were 2.8 and 1.9 micrograms ml-1, respectively, using UV detection at 280 nm. Accuracy for each drug was 102-103%.

Topics: Anti-Inflammatory Agents, Non-Steroidal; Buffers; Cations; Electrophoresis; Hydrogen-Ion Concentration; Propionates; Solutions; Sulindac