Enantioselective analysis of ofloxacin and ornidazole in pharmaceutical formulations by capillary electrophoresis using single chiral selector and computational calculation of their inclusion complexes.
A capillary electrophoretic method for the separation of the enantiomers of both ofloxacin and ornidazole is described. Several parameters affecting the separation were studied, including the type and concentration of chiral selector, buffer pH, voltage and temperature. Good chiral separation of the racemic mixtures was achieved in less than 16 min with resolution factors Rs=5.45 and 6.28 for ofloxacin and ornidazole enantiomers, respectively. Separation was conducted using a bare fused-silica capillary and a background electrolyte (BGE) of 50 mM H(3)PO(4)-1 M tris solution; pH 1.85; containing 30 mg mL(-1) of sulfated-beta-cyclodextrin (S-beta-CD). The separation was carried out in reversed polarity mode at 25 degrees C, 18 kV, detection wavelength at 230 nm and using hydrodynamic injection for 15 s. Acceptable validation criteria for selectivity, linearity, precision, and accuracy were studied. The limits of detection (LOD) and limits of quantitation (LOQ) of the enantiomers (ofloxacin enantiomer 1 (OF-E1), ofloxacin enantiomer 2 (OF-E2), ornidazole enantiomer 1 (OR-E1) and ornidazole enantiomer 2 (OR-E2)) were (0.52, 0.46, 0.54, 0.89) and (1.59, 1.40, 3.07, 2.70) microg mL(-1), respectively. The proposed method was successfully applied to the assay of enantiomers of both ofloxacin and ornidazole in pharmaceutical formulations. The computational calculations for the enantiomeric inclusion complexes rationalized the reasons for the different migration times between the ofloxacin and ornidazole enantiomers.
Al Azzam
Khaldun M
KM
School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia.
Saad
Bahruddin
B
Adnan
Rohana
R
Aboul-Enein
Hassan Y
HY
D000900:Anti-Bacterial Agents / Q000302:isolation & purification*; D000981:Antiprotozoal Agents / Q000302:isolation & purification*; D004304:Dosage Forms; D019075:Electrophoresis, Capillary / Q000379:methods*; D057230:Limit of Detection; D016014:Linear Models; D008958:Models, Molecular; D015242:Ofloxacin / Q000302:isolation & purification*; D009950:Ornidazole / Q000302:isolation & purification*; D013237:Stereoisomerism
D000900:Anti-Bacterial Agents; D000981:Antiprotozoal Agents; D004304:Dosage Forms; D009950:Ornidazole; D015242:Ofloxacin