Critical freezing rate in freeze drying nanocrystal dispersions
- 1 March 2006
- journal article
- research article
- Published by Elsevier BV in Journal of Controlled Release
- Vol. 111 (1-2), 185-192
- https://doi.org/10.1016/j.jconrel.2005.12.003
Abstract
Recent advances in nanoparticle technologies have significantly enhanced the oral and parenteral delivery of poorly water-soluble active pharmaceutical ingredients (APIs). However, reports have been limited on the various drying procedures to convert a liquid nanocrystal dispersions into solid dosage forms. The solid dosage form should consist of nanocrystals that can readily reconstitute into their original size upon dissolution in water. Herein, the freeze drying process of nanocrystal dispersions was examined at varying freezing rates (speed of freezing interface). As freezing rate decreases, more particle–particle aggregation developed. A critical freezing rate, below which the dried nanocrystals cannot be re-dispersed, was identified based on the plot of the particle size of reconstituted nanocrystals versus freezing rate. Freeze drying at a freezing rate near the critical value produces dry powders of bimodal particle size distribution after re-dispersion. In addition, API concentration was found to significantly affect the critical freezing rate and therefore the re-dispersibility of dry powders. The concept of critical freezing rate is critical for the development of solid dosage forms of liquid nanocrystal dispersions.Keywords
This publication has 27 references indexed in Scilit:
- Prolonged circulation of large polymeric nanoparticles by non-covalent adsorption on erythrocytesJournal of Controlled Release, 2004
- Intrinsic adhesion force of lubricants to steel surfaceJournal of Pharmaceutical Sciences, 2004
- Three Distinct Scenarios under Polymer, Surfactant, and Colloidal InteractionMacromolecules, 2003
- Coadsorption of Sodium Dodecyl Sulfate with Hydrophobically Modified Nonionic Cellulose Polymers. 1. Role of Polymer Hydrophobic ModificationLangmuir, 2003
- Spray‐freeze‐drying for protein powder preparation: Particle characterization and a case study with trypsinogen stabilityJournal of Pharmaceutical Sciences, 2002
- A Different Approach to NanothermodynamicsNano Letters, 2001
- Inorganic particle toughening II: toughening mechanisms of glass bead filled epoxiesPolymer, 2000
- Nanosuspensions of poorly soluble drugs — reproducibility of small scale productionInternational Journal of Pharmaceutics, 2000
- Effect of Grinding with Hydroxypropyl Cellulose on the Dissolution and Particle Size of a Poorly Water-Soluble Drug.CHEMICAL & PHARMACEUTICAL BULLETIN, 1999
- Sterile Filtration of NanoCrystal™ Drug FormulationsDrug Development and Industrial Pharmacy, 1997