Stability-indicating HPLC-DAD methods for determination of two binary mixtures: Rabeprazole sodium-mosapride citrate and rabeprazole sodium-itopride hydrochloride

Abstract

Two selective stability-indicating HPLC methods are described for determination of rabeprazole sodium (RZ)-mosapride citrate (MR) and RZ-itopride hydrochloride (IO) mixtures in the presence of their ICH-stress formed degradation products. Separations were achieved on X-Bridge C18 column using two mobile phases: the first for RZ-MR mixture consisted of acetonitrile: 0.025 M KH₂PO₄ solution: TEA (30:69:1 v/v; pH 7.0); the second for RZ-IO mixture was at ratio of 25:74:1 (v/v; pH 9.25). The detection wavelength was 283 nm. The two methods were validated and validation acceptance criteria were met in all cases. Peak purity testing using contrast angle theory, relative absorbance and log A versus the wavelengths plots were presented. The % recoveries of the intact drugs were between 99.1% and 102.2% with RSD% values less than 1.6%. Application of the proposed HPLC methods indicated that the methods could be adopted to follow the stability of their formulations.

Keywords: Itopride hydrochloride; Mosapride citrate; Peak purity; Rabeprazole sodium; Stability-indicating HPLC–DAD.

Fig. 1

Structural formulae of the investigated drugs.

Fig. 2

Chromatogram of a mixture of stress degradation products of RZ–MR in their binary mixture and their corresponding spectrum index plots.

Fig. 3

Chromatogram of a mixture of stress degradation products of RZ–IO in their binary mixture and their corresponding spectrum index plots.

Fig. 4

Chromatograms of mixture of acid (A), alkaline (B), oxidation (C), neutral (D) and photo induced (E) degradation of RZ and MR in their mixture (I) and RZ and IO in their mixture (II).

Fig. 5

The spectrograms (A), their log A (B) and their relative absorption (RA) (C) spectra versus the wavelength plots of RZ–MR peaks in their ICH-stress formed degradation (I) and RZ–IO peaks in their ICH-stress formed degradation (II).

Fig. 6

(A) Representative chromatogram of test RZ–MR capsules solution labeled to contain 200 µg/mL of RZ and 150 µg/mL of MR, (B) Representative chromatogram of test RZ–IO capsules solution labeled to contain 20 µg/mL of RZ and 150 µg/mL of IO.