Determination of cefsulodin, cefmenoxime, and cefadroxil as residues on surfaces.

Cefsulodin, cefmenoxime, and cefadroxil are degraded instantaneously in aqueous sodium hypochlorite, sodium hypochlorite-detergent, or alkaline detergent solutions. These alkaline solutions are used to clean surfaces that have been exposed to the cephalosporins. The cleaned surfaces are monitored for residual drug levels (microgram) using a wet swab-dry swab technique. After extraction from the swabs, the content of the respective cephalosporin is determined in the solution by high-performance liquid chromatography. The limit of detection for each of the compounds is 0.1 microgram/ml. Recoveries from nonporous surfaces ranged from 56 to 102%.

Determination of clarithromycin as a contaminant on surfaces by high-performance liquid chromatography using electrochemical detection.

Microgram levels of clarithromycin residues on various surfaces are quantitated. After cleaning, any residual clarithromycin remaining is removed from the surface by a wet swab-dry swab technique. High-performance liquid chromatography with electrochemical detection is used for quantitation of the resulting solutions. Recoveries ranged from 93 to 118%.

Analysis of oral suspensions containing sulfonamides in combination with erythromycin ethylsuccinate.

The sulfonamides and erythromycin ethylsuccinate in combination oral suspensions were determined by high-performance liquid chromatography and automated turbidimetry, respectively. The chromatographic procedure was rapid, specific, and stability-indicating for sulfisoxazole acetyl and the trisulfapyrimidines using a reversed-phase system with UV detection at 254 nm. Erythromycin ethylsuccinate did not interfere with the sulfonamide analysis and these compounds were assayed with relative standard deviations (RDS) ranging from +/- 2.1 to +/- 3.1%. Erythromycin ethylsuccinate was determined as erythromycin with RSD values of +/- 1.3 or 3.5% without interference by the sulfonamides present.