Schiller S.,Saarland University |
Schiller S.,Research Pharmaceutics and Drug Product Development |
Hanefeld A.,Research Pharmaceutics and Drug Product Development |
Schneider M.,Saarland University |
Lehr C.-M.,Saarland University
Pharmaceutical Research | Year: 2015
Abstract Purpose: Although nanomaterials are under investigation for a very broad range of medical applications, only a small fraction of these are already commercialized or in clinical development. A major challenge for the translation of nanomedicines into the clinic is the missing scalability of the available lab scale preparation methods and, ultimately, non-identical samples during early and late research. Methods: Protein-loaded PLGA nanoparticles using focused ultrasound in an emulsion solvent diffusion method were prepared in different batch sizes to evaluate achievable mean size, protein loading, and yield. Results: Using the same equipment, nanoparticles could be prepared in batch sizes from 1 mg to 2.5 g. Size and yield were directly controllable by the amount of incident energy with good reproducibility. The nanoparticles displayed similar mean size, protein loading, and nanoparticle yield in batch sizes over three orders of magnitude. A scalable purification method based on diafiltration was established. Conclusions: The proposed method enables for feasibility studies during early research using just a small amount of polymer and protein, while at the same time it allows for larger scale production at later stages. As the proposed method further relies on contact-free energy transmission, it is especially suited for the preparation of clinical research samples. © 2015 Springer Science+Business Media New York.
Anhalt K.,Research Pharmaceutics and Drug Product Development |
Anhalt K.,University of Heidelberg |
Geissler S.,Research Pharmaceutics and Drug Product Development |
Harms M.,Research Pharmaceutics and Drug Product Development |
And 3 more authors.
Pharmaceutical Research | Year: 2012
Purpose Nanocrystals exhibit enhanced dissolution rates and can effectively increase the bioavailability of poorly water soluble drug substances. However, methods for in vitro characterization of dissolution are unavailable. The objective of this study was to develop an in situ noninvasive analytical method to measure dissolution of crystalline nanosuspensions based on light scattering. Methods Fenofibrate nanosuspensions were prepared by wet media milling. Their solubilities and dissolution profiles in simulated gastric fluid supplemented with 0.1% Tween® 80 were measured in a small scale setup with an instrument for dynamic light scattering and the intensity of scattered light as readout parameter. Results A good correlation was achieved between the dissolution profile of a nanosuspension measured in the light scattering setup and a conventional dissolution experiment. Nanosuspensions of 120-270 nm size could be distinguished by the light scattering method. The suspensions dissolved within 1.9- 12.3 min. Over a concentration range of 40-87%of the solubility dissolution profiles of a nanosuspension with 140 nm were monitored and the determined total dissolution times were in good agreement with the Noyes-Whitney dissolution model. Conclusions A noninvasive, sensitive and reproducible method is presented to assess nanocrystal dissolution. In situ measurements based on light scattering allow a straightforward experimental setup with high temporal resolution. © Springer Science+Business Media, LLC 2012.