Dwarfism Research Today is a free monthly online journal that collates and summarizes the latest research about Dwarfism, including details on genetics, diet, mental and motor development. | ||||||||
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Preclinical and clinical in vitro in vivo correlation of an hGH dextran microsphere formulation.Vlugt-Wensink KD, de Vrueh R, Gresnigt MG, Hoogerbrugge CM, van Buul-Offers SC, de Leede LG, Sterkman LG, Crommelin DJ, Hennink WE, Verrijk R OctoPlus Technologies, OctoPlus b.v., Zernikedreef 12, 2333 CL, Leiden, The Netherlands. Wensink@octoplus.nl PURPOSE: To investigate the in vitro in vivo correlation of a sustained release formulation for human growth hormone (hGH) based on hydroxyethyl methacrylated dextran (dex-HEMA) microspheres in Pit-1 deficient Snell dwarf mice and in healthy human volunteers. MATERIALS AND METHODS: A hGH-loaded microsphere formulation was developed and tested in Snell dwarf mice (pharmacodynamic study) and in healthy human volunteers (pharmacokinetic study). RESULTS: Single subcutaneous administration of the microspheres in mice resulted in a good correlation between hGH released in vitro and in vivo effects for the hGH-loaded microsphere formulation similar to daily injected hGH indicating a retained bioactivity. Testing the microspheres in healthy volunteers showed an increase (over 7-8 days) in hGH serum concentrations (peak concentrations: 1-2.5 ng/ml). A good in vitro in vivo correlation was obtained between the measured and calculated (from in vitro release data) hGH serum concentrations. Moreover, an increased serum concentration of biomarkers (insulin-like growth factor-I (IGF-I), IGF binding protein-3 (IGFBP-3) was found again indicating that bioactive hGH was released from the microspheres. CONCLUSIONS: Good in vitro in vivo correlations were obtained for hGH-loaded dex-HEMA microspheres, which is an important advantage in predicting the effect of the controlled drug delivery product in a clinical situations. Published 6 November 2007 in Pharm Res, 24(12): 2239-48.
© 2005-2008 Dwarfism Research Today. All Rights Reserved. |
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