Classification of the ibuprofen active pharmaceutical ingredients by chemical patterns combining HPLC, 1H-NMR spectroscopy and chemometrics: traceability of legal medicines.

INTRODUCTION: Ibuprofen is one of the widespread used non-steroidal anti-inflammatory drugs. Ibuprofen active ingredient is manufactured in many sites located all around the world. The aim of this paper was to classify the geographical source of ibuprofen active pharmaceutical ingredients (APIs) from the legal market, based on chemical characteristics and its impurity pattern and to define a geographical fingerprint. METHODS: To classify ibuprofen in different geographical groups, the chemometrics by principal component analysis (PCA) and Cluster analysis was applied to HPLC, 1H-NMR data of twenty-four samples of APIs from approved manufacturers located in different European and Asian countries. RESULTS: The PCA showed clearly two different geographical groups, based on particular patterns of European or Indian samples; the cluster analysis showed the similarity of group. CONCLUSION: The chemometric analysis is an important tool for tracking the geographical origin of APIs. This could be useful to supplement the quality control ensuring safety of the medicinal products in legal market and dealing with the evolving changes of the illegal market.

Comparison of reversed-phase enantioselective HPLC methods for determining the enantiomeric purity of (S)-omeprazole in the presence of its related substances.

A simple analytical high-performance liquid chromatography (HPLC) method was applied for the enantiomeric excess determination of esomeprazole ((S)-OME), the enantiopure active ingredient contained in drug products, in the presence of its potential organic impurities A-E. The enantioselective separation was accomplished on the immobilized-type Chiralpak ID-3 chiral stationary phase (CSP) under reversed-phase conditions. The results were evaluated and compared with those obtained by the official enantioselective method of European Pharmacopoeia used as the reference for checking the enantiomeric excess of (S)-OME. It has been established that the use of the Chiralpak ID-3 CSP allows the determination of the enantiomeric purity of (S)-OME without any interference coming from its chiral and achiral related substances. The analytical procedure of the drug regulatory agencies based on the AGP CSP suffered instead from poor specificity due to overlap of the peaks pertinent to the achiral impurity A and the chiral impurity (R)-OME (impurity F).

Direct HPLC enantioseparation of omeprazole and its chiral impurities: application to the determination of enantiomeric purity of esomeprazole magnesium trihydrate.

Analytical and semipreparative high-performance liquid chromatography (HPLC) enantioseparation of the proton-pump inhibitor omeprazole (OME) and its potential organic chiral impurities were accomplished on the immobilised-type Chiralpak IA chiral stationary phase (CSP) under both polar organic and normal-phase conditions. The (S)-enantiomers were isolated with a purity of >99% ee and their absolute configuration was empirically assigned by circular dichroism (CD) spectroscopy. A chemo- and enantioselective HPLC method was validated to control the enantiomeric purity of the (S)-enantiomer of OME (ESO), an active ingredient contained in drug products, in the presence of chiral and achiral related substances. The precision, linearity and accuracy of the determination of the (R)-impurity as well as the recovery of ESO from a pharmaceutical preparation were determined. The proposed method uses the mixture methyl tert-butylether (MtBE)-ethyl acetate (EA)-ethanol (EtOH)-diethylamine (DEA) 60:40:5:0.1 (v/v/v/v) as a mobile phase. In these conditions, linearity over the concentration range 0.5-25 microg/ml for (R)-enantiomer was obtained. The limits of detection and quantification were 99 and 333 ng/ml, respectively. The intra and inter-day assay precision was less than 2% (RSD%).

Direct high-performance liquid chromatography enantioseparation of terazosin on an immobilised polysaccharide-based chiral stationary phase under polar organic and reversed-phase conditions.

High-performance liquid chromatography (HPLC) enantioseparation of terazosin (TER) was accomplished on the immobilised-type Chiralpak IC chiral stationary phase (CSP) under both polar organic and reversed-phase modes. A simple analytical method was validated using a mixture of methanol-water-DEA 95:5:0.1 (v/v/v) as a mobile phase. Under reversed-phase conditions good linearities were obtained over the concentration range 8.76-26.28 microg mL(-1) for both enantiomers. The limits of detection and quantification were 10 and 30 ng mL(-1), respectively. The intra- and inter-day assay precision was less than 1.66% (RSD%). The optimised conditions also allowed to resolve chiral and achiral impurities from the enantiomers of TER. The proposed HPLC method supports pharmacological studies on the biological effects of the both forms of TER and analytical investigations of potential drug formulations based on a single enantiomer. At the semipreparative scale, 5.3 mg of racemic sample were resolved with elution times less than 12 min using a mobile phase consisting of methanol-DEA 100:0.1 (v/v) and both enantiomers were isolated with a purity of > or = 99% enantiomeric excess (ee). The absolute configuration of TER enantiomers was assigned by comparison of the measured specific rotations with those reported in the literature.