Lyophilization of a triply unsaturated phospholipid: Effects of trace metal contaminants
| Autor: | Theodore W. Randolph, Thomas J. Anchordoquy, Nicole M. Payton, Jamie L. Betker, Michael F. Wempe |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
Sucrose
Reducing agent Carbohydrates Pharmaceutical Science Buffers Article Ferrous Freeze-drying chemistry.chemical_compound Freezing Sulfites Ferrous Compounds Phospholipids Chemical decomposition Liposome Aqueous solution Chromatography Chemistry Osmolar Concentration General Medicine Lipids Trace Elements Freeze Drying Metals Ionic strength Phosphatidylcholines Drug Contamination Biotechnology |
| Zdroj: | European Journal of Pharmaceutics and Biopharmaceutics. 85:306-313 |
| ISSN: | 0939-6411 |
| DOI: | 10.1016/j.ejpb.2013.03.028 |
| Popis: | As liquid liposomal formulations are prone to chemical degradation and aggregation, these formulations often require freeze drying (e.g. lyophilization) to achieve sufficient shelf-life. However, liposomal formulations may undergo oxidation during lyophilization and/or during prolonged storage. The goal of the current study was to characterize the degradation of 1, 2-dilinolenoyl-sn-glycero-3-phosphocholine (DLPC) during lyophilization, and to also probe the influence of metal contaminants in promoting the observed degradation. Aqueous sugar formulations containing DLPC (0.01 mg/ml) were lyophilized, and DLPC degradation was monitored using HPLC/UV and GC/MS methods. The effect of ferrous ion and sucrose concentration, as well as lyophilization stage promoting lipid degradation, was investigated. DLPC degradation increased with higher levels of ferrous ion. After lyophilization, 103.1% ± 1.1%, 66.9% ± 0.8%, and 28.7% ± 0.7% DLPC remained in the sucrose samples spiked with 0.0 ppm, 0.2 ppm and 1.0 ppm ferrous ion, respectively. Lipid degradation predominantly occurs during the freezing stage of lyophilization. Sugar concentration and buffer ionic strength also influence the extent of lipid degradation, and DLPC loss correlated with degradation product formation. We conclude that DLPC oxidation during the freezing stage of lyophilization dramatically compromises the stability of lipid-based formulations. In addition, we demonstrate that metal contaminants in sugars can become highly active when lyophilized in the presence of a reducing agent. |
| Databáze: | OpenAIRE |
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