Aciphex
New liquid chromatographic method for determination of rabeprazole sodium in coated tablets.

Garcia CV, Paim CS, Steppe M.

Universidade Federal do Rio Grande do Sul., Programa de Pos-graduacao em Ciencias Farmaceuticas, Faculdade de Farmacia, Av. Ipiranga, Porto Alegre/RS CEP, Brazil. cassiavgarcia yahoo.com.br

Rabeprazole sodium is a proton pump inhibitor that covalently binds and inactivates the gastric parietal cell proton pump (H+/K+ ATPase). Little has been published about the quantitative determination of this drug. The aim of this research was to develop a new liquid chromatographic method for quantitative determination of rabeprazole in coated tablets. The system consisted of a Hypersil Keystone Betabasic C8 column (250 x 4.6 mm, 5 microm particle size), an isocratic acetonitrile-water (35 + 65) mobile phase at a flow rate of 1.0 mL/min, and a diode array detector set at 282 nm. The following validation parameters were evaluated: linearity, precision, accuracy, specificity, detection and quantitation limits, and robustness. The method showed good linearity in the concentration range of 10-70 microg/mL. The quantitation limit was 2.43 microg/mL, and the detection limit was 0.80 microg/mL. The intra- and interday precision data showed that the method has good reproducibility (relative standard deviation = 1.03). Accuracy and robustness were also evaluated, and the results were satisfactory. The mean recovery was 101.61%. The analysis of a placebo mixture demonstrated the method is also specific.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15295877&dopt=Abstract rabeprazole Aciphex



Aciphex
Improvement in clinical course and laryngeal appearance in selected patients with chronic laryngitis after eight weeks of therapy with rabeprazole.

Klopocka M, Sinkiewicz A, Budzynski J, Pulkowski G, Swiatkowski M.

The Ludwik Rydygier University of Medicine, Bydgoszcz, Poland. mariaklopocka wp.pl

BACKGROUND: One well-known extraesophageal manifestation of gastroesophageal reflux disease (GERD) is chronic laryngitis. The aim of this study was to estimate the efficiency of eight weeks of treatment with the PPI rabeprazole in a selected group of patients with chronic idiopathic laryngitis without typical GERD symptoms. MATERIAL/METHODS: Seventeen patients (nine men and eight women) aged 35-72 years, with long histories (0.5 to 6 years) of chronic idiopathic laryngitis were included in the study. Larynx appearance was estimated by laryngostroboscopy. This examination, as well as interview and physical examination were performed in all patients at the start of the study and after 8 weeks of treatment with 20 mg rabeprazole taken orally twice a day. RESULTS: There was remarkably good therapeutic outcome, clinical symptoms such as hoarseness and pharyngeal pain resolved, respectively, in 68.7 and 78.5% of patients and laryngeal signs in 50-80%, except for weak tension of the vocal cords which was observed in 12 patients at the start and end of the study. CONCLUSIONS: Treatment with a proton pump inhibitor can be considered as a first-line diagnostic and therapeutic method in patients with idiopathic chronic laryngitis. Weak tension of vocal cords was often seen in these patients and persisted after the 8-week-long treatment.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15448612&dopt=Abstract rabeprazole Aciphex



Aciphex
Effect of rabeprazole on MDR1-mediated transport of Rhodamine 123 in Caco-2 and Hvr100-6 cells.

Itagaki F, Homma M, Takara K, Ohnishi N, Yokoyama T, Sakaeda T, Yagami T, Kobayashi H, Okamura N, Kohda Y.

Department of Pharmaceutical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ten-nodai, Ibaraki, Japan. tfumioi-tuk umin.ac.jp

The aim of our study was to investigate the effects of rabeprazole, a proton pump inhibitor, on MDR1 expressed on human colon carcinoma cell line, Caco-2, and MDR1-overexpressing human cervical carcinoma cell line, HeLa cells selected by exposure to 100 nM vinblastine (Hvr100-6 cells). Inhibitory effects of rabeprazole on MDR1-mediated transport of Rhodamine123 were examined in these cells. A thousand micro molar rabeprazole increased Rhodamine 123 uptakes in Caco-2 and Hvr100-6 cells by 68% and 185%, respectively. No significant effects of rabeprazole were observed at the concentration of 1-100 microM. Since rabeprazole did not show any effects on Rhodamine 123 transport via MDR1 at the plasma levels (approximately 1 microM), it was considered that the drug interaction with MDR1 substrates would be minimal even though the interaction occurred in the patients with rabeprazole treatment.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15467223&dopt=Abstract rabeprazole Aciphex