477 research outputs found

    Bioequivalence of Oral Products and the Biopharmaceutics Classification System: Science, Regulation, and Public Policy

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    The demonstration of bioequivalence (BE) is an essential requirement for ensuring that patients receive a product that performs as indicated by the label. The BE standard for a particular product is set by its innovator, and this standard must subsequently be matched by generic drug products. The Biopharmaceutics Classification System (BCS) sets a scientific basis for an improved BE standard for immediate-release solid oral dosage forms. In this paper, we discuss BE and the BCS, as well as the issues that are currently relevant to BE as a pharmaceutical product standard

    An oral multiparticulate, modified-release, hydrocortisone replacement therapy that provides physiological cortisol exposure

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    Objective It is not possible with current hydrocortisone replacement to mimic the diurnal cortisol profile in patients with adrenal insufficiency. Previous attempts with modified-release technology were unsuccessful. Our objective was to develop hydrocortisone formulations that recreate the diurnal cortisol profile using multiparticulate technology. Design and Measurements Screening by in vitro dissolution profiles, pharmacokinetic (PK) testing in dexamethasone-suppressed dogs and humans, and comparison with a reference population. Setting Field laboratories and clinical research facility. Results Formulations were generated using an enteric (delayed release) design configuration with an extended (sustained release) dissolution profile. In vitro dissolution confirmed delayed and sustained hydrocortisone release. However, in dogs and humans, sustained release resulted in reduced bioavailability. A formulation, DIURF-006, was developed that maintained delayed release but omitted the sustained-release functionality. PK characterization of DIURF-006 showed that, despite absence of a sustained-release component, absorption was sufficiently sustained to deliver extended hydrocortisone absorption. In dexamethasone-suppressed volunteers (n = 16) receiving a twice-daily ‘toothbrush’ regimen (20 mg at 23:00 h and 10 mg at 07:00 h), DIURF-006 gave a similar cortisol profile to physiological cortisol levels: DIURF-006 vs physiological, Geomean AUC 5610 vs 4706 h * nmol/l, Geomean Cmax 665 vs 594 nmol/l and Median Tmax 8·5 h vs clock time 08:12 h for peak cortisol. The relative bioavailability of DIURF-006 vs hydrocortisone was 89%, and cortisol levels increased linearly with doses between 5 and 30 mg. Conclusion A multiparticulate oral hydrocortisone formulation with only an enteric coat provides delayed and sustained absorption and when given in a ‘toothbrush’ regimen provides physiological cortisol exposure

    PRESYSTEMIC ELIMINATION OF THE fl-BLOCKER PAFENOLOL IN THE RAT AFTER ORAL AND INTRAPERITONEAL ADMINISTRATION AND IDENTIFICATION OF A MAIN METABOLITE IN BOTH RATS AND HUMANS

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    ABSTRACT: Pafenolol is a 91-adrenoreceptor antagonist exhibiting some intereating oral absorption properties in both rat and humans

    Effect of simvastatin on bone markers in osteopenic women: a placebo-controlled, dose-ranging trial [ISRCTN85429598]

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    BACKGROUND: Hydroxymethylglutaryl coenzyme A reductase inhibitors increase new bone formation in vitro and in rodents. Results of epidemiologic analyses evaluating the association between use of these cholesterol-lowering drugs, bone mineral density and fracture have been mixed. METHODS: Women (n = 24) with osteopenia, assessed by broad band ultrasound attenuation, were randomized to simvastatin 20 mg, 40 mg or identical-appearing placebo for 12 weeks. Fasting lipid profiles and biochemical markers of bone formation (bone-specific alkaline phosphatase) and resorption (N-telopeptides and C-terminal propeptide of type 1 collagen) were measured at baseline, 6 and 12 weeks. RESULTS: Plasma low density lipoprotein-cholesterol concentration fell 7%, 39% (p < 0.01 vs baseline) and 47% (p < 0.01 vs baseline) after 12 weeks of treatment with placebo, simvastatin 20 mg and 40 mg, respectively. At baseline, bone marker concentrations were similar in the three treatment groups. At 6 and 12 weeks, bone marker concentrations were not different from baseline, and no significant differences in bone marker concentrations were observed between treatment groups at either 6 or 12 weeks. CONCLUSION: Among osteopenic women, treatment with simvastatin for 12 weeks did not affect markers of bone formation or resorption

    Comparison of Human Duodenum and Caco-2 Gene Expression Profiles for 12,000 Gene Sequences Tags and Correlation with Permeability of 26 Drugs

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    Purpose . To compare gene expression profiles and drug permeability differences in Caco-2 cell culture and human duodenum.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41490/1/11095_2004_Article_450750.pd

    Anthocyanin management in fruits by fertilization

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    Anthocyanins are water-soluble vacuolar plant pigments that are mainly synthesized in epidermal layers and the flesh of fruits such as apples, cherries, grapes, and other berries. Because of their attractive red to purple coloration and their health-promoting potential, anthocyanins are significant determinants for the quality and market value of fruits and fruit-derived products. In crops, anthocyanin accumulation in leaves can be caused by nutrient deficiency which is usually ascribed to insufficient nitrogen or phosphorus fertilization. However, it is a little-known fact that the plant’s nutrient status also impacts anthocyanin synthesis in fruits. Hence, strategic nutrient supply can be a powerful tool to modify the anthocyanin content and consequently the quality and market value of important agricultural commodities. Here we summarize the current knowledge of the influence of plant nutrients on anthocyanin synthesis in fruits of major global market value and discuss the underlying cellular processes that integrate nutrient signaling with fruit anthocyanin formation. It is highlighted that fertilization that is finely tuned in amount and timing has the potential to positively influence the fruit quality by regulating anthocyanin levels. We outline new approaches to enrich plant based foods with health-promoting anthocyanins

    A promising camptothecin derivative: Semisynthesis, antitumor activity and intestinal permeability

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    Oral administration of camptothecin (Cm) derivatives and other antitumoral agents is being actively developed in order to improve the quality of life of patients with cancer. Though several lipophilic derivatives of CPT have shown interesting oral bioavailability in preclinical and clinical studies, only Topotecan has been approved for this route of administration. Semisynthesis, antitumor activity, biological inhibition mechanism, and in situ intestinal permeability of 9, 10-[1,3]-Dioxinocamptothecin (CDiox), an unexplored CPT derivative, have been studied in this paper. The hexacyclic analog was as effective as Topotecan and CPT in different tumor cell lines, showing an expected similar apoptosis cell mechanism and high ability to inhibit DNA synthesis in HeLa, Caco-2, A375 and MDA-MB-231 cell lines. Furthermore, in vitro and in situ pharmacokinetics transport values obtained for CDiox displayed more favorable absorption profile than CPT and Topotecan. (C) 2014 Elsevier Masson SAS. All rights reserved.G.R.-B. acknowledges Instituto de Tecnologia Quimica for a scholarship; Consolider-Ingenio 2010 (proyecto MULTICAT), Sub-programa de Apoyo a Centros de Excelencia Severo Ochoa, and Agencia de Gestico, d'Ajuts Universiteris i de Recerca (2009 SGR 758, to S.S.) I.G.-A., V.M.-S., M.G.-A. and M. B. acknowledge financial support from the European Financial Commission (Red bioFarma DCI-ALA/19.09.01/10/21526/245-297/ALFA III (2010)). J.L.G.-G. acknowledges the financial support of the CIBERER (Biomedical Network Research Center for Rare Diseases) ISCIII.Rodríguez Berna, G.; Mangas Sanjuan, V.; Gonzalez Alvarez, M.; Gonzalez Álvarez, I.; Garcia Gimenez, JL.; Díaz Cabañas, MJ.; Bermejo, M.... (2014). A promising camptothecin derivative: Semisynthesis, antitumor activity and intestinal permeability. European Journal of Medicinal Chemistry. 83:366-373. doi:10.1016/j.ejmech.2014.06.050S3663738
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