Pharmacokinetics of selamectin following intravenous, oral and topical administration in cats and dogs.

The pharmacokinetics of selamectin were evaluated in cats and dogs, following intravenous (0.05, 0.1 and 0.

Strategies for peak-purity assessment in liquid chromatography.

One of the key requirements for the validation of chromatographic methods is to determine the purity of a chromatographic peak. Statistical modelling of the chromatographic process suggests that overlapping components are highly probable in a chromatogram. Hence extensive efforts have been directed at the development of sensitive, reliable and robust methods to assess peak purity.

A multiwavelength approach to the selection of absorbance ratios for the assessment of chromatographic peak purity.

The routine use of diode-array detectors (DAD), based on the linear photodiode array device, has transformed the practice of UV-vis detection in liquid chromatography (LC). Multiwavelength detection is widely employed to generate absorbance ratios as a relatively non-specific method for characterizing peak purity in LC. If several wavelength pairs are selected the selectivity of the absorbance ratio method and its sensitivity to an interfering impurity can be increased, however, these attributes still depend on the selection of suitable pairs of wavelengths.

Post-column continuous-flow analysis combined with reversed-phase liquid chromatography and computer-aided detection for the characterisation of peptides.

Peptide mapping is a key technique for structural identification of new proteins or the products of recombinant gene technology. The recognition of oligopeptides, separated by reversed-phase liquid chromatography, is limited by the conventional reliance on the correlation of retention times with standards, supported by dual-wavelength chromatograms. It has been reported that the recognition of phenolic compounds can be achieved by a novel technique, based on computer-aided photodiode-array detection of the pH-shifted solutes after post-column continuous-flow analysis.