| Title: | Solvent-Assisted Secondary Drying of Spray-Dried Polymers |
| Author(s): | Shepard KB; Dower AM; Ekdahl AM; Morgen MM; Baumann JM; Vodak DT; |
| Address: | "Research & Development, Lonza Pharma, Biotech and Nutrition, Bend, Oregon, USA. Kimberly.shepard@lonza.com. Product Development, Lonza Pharma, Biotech and Nutrition, Bend, Oregon, USA. Department of Chemical Engineering, University of Texas at Austin, Austin, Texas, USA. Research & Development, Lonza Pharma, Biotech and Nutrition, Bend, Oregon, USA" |
| DOI: | 10.1007/s11095-020-02890-0 |
| ISSN/ISBN: | 1573-904X (Electronic) 0724-8741 (Print) 0724-8741 (Linking) |
| Abstract: | "PURPOSE: The purpose of this work is to introduce solvent-assisted secondary drying, a method used to accelerate the residual solvent removal from spray dried materials. Spray-drying is used to manufacture amorphous solid dispersions, which enhance the bioavailability of active pharmaceutical ingredients (APIs) with low aqueous solubility. In the spray-drying process, API and excipients are co-dissolved in a volatile organic solvent, atomized into droplets through a nozzle, and introduced to a drying chamber containing heated nitrogen gas. The product dries rapidly to form a powder, but small amounts of residual solvent (typically, 1 to 10 wt%) remain in the product and must be removed in a secondary-drying process. For some spray-dried materials, secondary drying by traditional techniques can take days and requires balancing stability risks with process time. METHODS: Spray-dried polymers were secondary dried, comparing the results for three state-of-the-art methods that employed a jacketed, agitated-vessel dryer: (1) vacuum-only drying, (2) water-assisted drying, or (3) methanol-assisted drying. Samples of material were pulled at various time points and analyzed by gas chromatography (GC) and Karl Fischer (KF) titration to track the drying process. RESULTS: Model systems were chosen for which secondary drying is slow. For all cases studied, methanol-assisted drying outperformed the vacuum-only and water-assisted drying methods. CONCLUSIONS: The observation that methanol-assisted drying is more effective than the other drying techniques is consistent with the free-volume theory of solvent diffusion in polymers" |
| Keywords: | "Chromatography, Gas *Desiccation Drug Compounding Excipients/chemistry Kinetics Mass Spectrometry Methanol/chemistry Polymers/*chemistry Powders Solubility Solvents/*chemistry Volatile Organic Compounds/*chemistry Water amorphous solid dispersion diffusio;" |
| Notes: | "MedlineShepard, Kimberly B Dower, April M Ekdahl, Alyssa M Morgen, Michael M Baumann, John M Vodak, David T eng 2020/08/02 Pharm Res. 2020 Jul 31; 37(8):156. doi: 10.1007/s11095-020-02890-0" |
