Abstract
Solid lipid implants (SLIs) prepared by twin-screw (tsc) extrusion represent a promising technology platform for the sustained release of pharmaceutical proteins. In this work, we report on two aspects, long-term release and stability of released protein. First, SLIs were produced by tsc-extrusion containing the low melting triglyceride H12 and the high melting triglyceride Dynasan D118. Two different proteins available in a freeze-dried matrix containing hydroxypropyl-beta-cyclodextrine (HP-beta-CD) were incorporated into the lipid matrix: a monoclonal antibody (mAb) from the IgG(1) class and the f(ab)-fragment Ranibizumab (Lucentis (R)). SLIs, composed of 10% protein lyophilizate and both triglycerides, were extruded at 35 degrees C and 40 rpm. Sustained release of both proteins was observed in a sustained manner for approximately 120 days. Protein load per implant was increased by three different approaches resulting in a protein load of 3.00 mg per implant without affecting the release profiles. The incubation medium containing the released protein was collected, concentrated and analyzed including liquid chromatography (SE-HPLC, IEX, HIC), electrophoresis (SDS-PAGE, on-chip gel electrophoresis) and FT-IR spectroscopy. The mAb showed a monomer loss of up to 7% (SE-HPLC) and IEX analysis revealed the formation of 16% acidic subspecies after 18 weeks. FT-IR spectra of mAb indicated the formation of random coil structures towards the end of the release study. Ranibizumab was mainly released in its monomeric form (>95%), and approximately 5% hydrophobic subspecies were formed after 18 weeks of release. FT-IR analysis revealed no changes in secondary structure. The release and stability profiles of both proteins underline the potential of SLIs as a delivery system. SLIs provide a promising platform for applications where really long-term release is needed, for example for intraocular delivery of anti-vascular endothelial growth factor (VEGF) drugs for age related macular degeneration (AMD).
Dokumententyp: | Zeitschriftenartikel |
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Fakultät: | Chemie und Pharmazie > Department für Pharmazie - Zentrum für Pharmaforschung |
Themengebiete: | 500 Naturwissenschaften und Mathematik > 540 Chemie |
ISSN: | 0939-6411 |
Sprache: | Englisch |
Dokumenten ID: | 54502 |
Datum der Veröffentlichung auf Open Access LMU: | 14. Jun. 2018, 09:56 |
Letzte Änderungen: | 04. Nov. 2020, 13:34 |