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Chlorpheniramine maleate (CLOR) enantiomers were quantified by ultraviolet spectroscopy and partial least squares regression. The CLOR enantiomers were prepared as inclusion complexes with beta-cyclodextrin and 1-butanol with mole fractions in the range from 50 to 100%. For the multivariate calibration the outliers were detected and excluded and variable selection was performed by interval partial least squares and a genetic algorithm. Figures of merit showed results for accuracy of 3.63 and 2.83% (S)-CLOR for root mean square errors of calibration and prediction, respectively. The ellipse confidence region included the point for the intercept and the slope of 1 and 0, respectively. Precision and analytical sensitivity were 0.57 and 0.50% (S)-CLOR, respectively. The sensitivity, selectivity, adjustment, and signal-to-noise ratio were also determined. The model was validated by a paired t test with the results obtained by high-performance liquid chromatography proposed by the European pharmacopoeia and circular dichroism spectroscopy. The results showed there was no significant difference between the methods at the 95% confidence level, indicating that the proposed method can be used as an alternative to standard procedures for chiral analysis.

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The determination of ibuprofen (IBU) enantiomers by chiral high-performance liquid chromatographic is described. The methodology is based on chiral recognition of ibuprofen by a chiral column based on cellulose tris(4-methylbenzoate) coated on silica gel (Chiralcel OJ-H). The mobile phase is n-hexane-2-propanol-trifluoroacetic acid (98:2:0.1, v/v/v). The flow rate was 1.0 mL/min, and UV detection was 254 nm. The samples of ibuprofen were prepared in n-hexane in the concentration range 50-100% of (S)-IBU 1 x 10(-3) mol/L. Calibration and validation method were performed with six and nine samples, respectively. Goodness-of-fit measures represented by correlation coefficient, y-intercept, and slope of the regression line were 0.9836, 21373, 2162, respectively. Average of the relative error of the proposed method was 3.0%, 0.9% (S)-IBU selectivity, and 2162% (S)-IBU-1 sensitivity. The minimum concentration difference between two samples that could be determined in the linear dynamic range was 0.4% (S)-IBU. Limits of detection and quantification were 8.1 and 27.0% (S)-IBU, respectively. These results indicate that the proposed method can be employed for determination of the enantiomeric composition of IBU.