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Application of LC and HPTLC-densitometry for the simultaneous determination of two multicomponent mixtures containing pyridoxine hydrochloride and cyanocobalamine

Hadad G. M., Abdel-Salam R. A., Abdel-Hameed E. A.

Acta Chromatographica

2013

Vol. 25, no. 3

431--450

Two methods were presented for the simultaneous determination of two multicomponent mixtures containing pyridoxine hydrochloride (B6) and cyanocobalamine (B12) with benfotiamine (BN) [mix. 1], or thiamine nitrate (B1) and diclofenac sodium (DC) [mix. 2]. The first high-performance liquid chromatographic (HPLC) method depends on the use of a cyanopropyl column at a flow rate of 1.5 mL min-1 with a mobile phase consisting of acetonitrile-25 mM ammonium acetate, pH 3.7 (10:90, v/v), for mix. 1 or acetonitrile-25 mM ammonium acetate, pH 5.0 by gradient elution, changing the proportion of the system linearly with a time schedule program, for mix. 2. Quantitation was achieved by UV detection at 220 nm. The second method was based on HPTLC separation followed by densitometric measurement of the spots at 254 nm. The separation was achieved on HPTLC silica gel F254 plates using chloroform-ethanol-water-acetic acid (5:8:2:0.5, v/v/v/v) for mix. 1 and chloroform-ethanol-water-acetic acid (1.5:8:2:0.5, v/v/v/v) for mix. 2. The proposed methods were successfully applied for the analysis of pharmaceutical formulations containing the two multicomponent combinations.

First detailed quantification of silymarin components in the leaves of Silybum marianum cultivated in egypt during different growth stages

Omar A. A, Hadad G. M, Badr J. M

Acta Chromatographica

2012

Vol. 24, no. 3

463--473

A high performance liquid chromatographic method was developed for the quantitative determination of the active components of silymarin in the leaves of Silybum marianum during different growth stages. In this study, taxifolin and six main active constituents in silymarin, including silydianin, silychristin, diastereomers of silybin (silybin A and B) and diastereomers of isosilybin (isosilybin A and B) were completely separated on a 5-μm ODS column (Luna, Phenomenex, USA) with a mobile phase consisting of methanol and 5 mM NaH2PO4 (pH 3.5 adjusted with phosphoric acid) in a ratio of 45:55 v/v. Quantitation was performed with UV detection at 280 nm, based on peak area. The concentration of each component, as well as the total silymarin concentration was determined and compared with those of the seeds, aiming at optimizing the utilization of the cultivated plant. The developed method was validated with respect to linearity, range, specificity, accuracy, precision, and robustness. The leaves were found to contain such concentrations of silymarin components that the yield is better per field area than that from the seeds. Moreover, the extraction of these components from leaves is nonexpensive and simpler than the extraction from seeds.