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AAPS PharmSciTech. 2006 December; 7(4): E95–E98.
Published online 2014 March 30. doi:  10.1208/pt070495
PMCID: PMC2750332

Tracking the physical aging of poly(ethylene oxide): A technical note

Summary and Conclusions

Physical aging of 2 types of PEO could be tracked by the combination of PALS, DSC, and SEM methods. After storing the samples at 40°C±2°C and 75%±5% RH, a decrease in the o-Ps lifetime values and an increase in the melting enthalpies as a function of storage time indicated a reorientation of the polymer chains. The limitations of monitoring enthalpy relaxation confirm the importance of methods that track volume relaxation, such as PALS. Structural changes could be observed even after a short storage time (4 weeks), which highlights the effect of further investigations of the influence of physical aging on the properties of PEO-containing dosage forms.

Keywords: Poly(ethylene oxide), physical aging, positron annihilation lifetime spectroscopy, differential scanning calorimetry, amorphous

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.
1. Rowe RC, Sheskey PJ, Weller PJ, editors. Handbook of Pharmaceutical Excipients. 4th ed. London, UK: Pharmaceutical Press; 2003. pp. 460–461.
2. Hutchinson JM. Physical aging of polymers. Prog Polym Sci. 1995;20:703–760. doi: 10.1016/0079-6700(94)00001-I. [Cross Ref]
3. Hay JN. The physical ageing of amorphous and crystalline polymers. Pure Appl Chem. 1995;67:1855–1858. doi: 10.1351/pac199567111855. [Cross Ref]
4. Süvegh K, Zelkó R. Physical aging of poly(vinylpyrrolidone) under different humidity conditions. Macromolecules. 2002;35:795–800. doi: 10.1021/ma011148l. [Cross Ref]
5. Zelkó R, Süvegh K. Comparison of the enthalpy recovery and free volume of poly(vinylpyrrolidone) during anomalous glassy to rubbery transition. Eur J Pharm Sci. 2004;21:519–523. doi: 10.1016/j.ejps.2003.11.013. [PubMed] [Cross Ref]
6. MacKenzie IK. Experimental Methods of Annihilation Time and Energy Spectrometry. In: Brandt W, Dupasquier A, editors. Positron Solid-State Physics. Amsterdam, The Netherlands: Elsevier; 1983. pp. 196–264.
7. Süvegh K, Vértes A, Hyodo T. Positronium as a sensitive detector of changes in molecular structure. Adv Mol Struct Res. 1999;5:313–357. doi: 10.1016/S1087-3295(99)80010-3. [Cross Ref]
8. Zelkó R, Süvegh K. Correlation between the release characteristics of theophylline and the free volume of polyvinylpyrrolidone. Eur J Pharm Sci. 2005;24:351–354. doi: 10.1016/j.ejps.2004.11.009. [PubMed] [Cross Ref]
9. Vernel J, Rychwalski RW, Pelisek V, Saha P, Schmidt M, Maurer FHJ. Physical aging in poly(ethylene oxide)/atactic-poly(methyl methacrylate) blends. Thermochim Acta. 1999;342:115–137. doi: 10.1016/S0040-6031(99)00291-9. [Cross Ref]
10. Zhao Y, Jasse B, Monnerie L. Orientation and relaxation in uniaxially stretched poly(methyl methacrylate)-poly(ethylene oxide) blends. Polym J. 1989;30:1643–1650. doi: 10.1016/0032-3861(89)90324-8. [Cross Ref]
11. Jin X, Zhang S, Runt J. Observation of a fast dielectric relaxation in semi-crystalline poly(ethylene oxide) Polym J. 2002;43:6247–6254. doi: 10.1016/S0032-3861(02)00560-8. [Cross Ref]
12. FDA/CDER . Guidance for Industry: Q1A(R2) Stability Testing of New Drug Substances and Products. Rockville, MD: Center for Drug Evaluation and Research, Center for Biologics Evaluation and Research, Food and Drug Administration; 2003.
13. Committee for Proprietary Medicinal Products . Guideline on Stability Testing of Existing Active Substances and Releated Finished Products. London, UK: The European Agency for the Evaluation of Medicinal Products; 2003.
14. Wunderlich B. Crystal Melting: Macromolecular Physics. New York, NY: Academic Press; 1980.
15. Bamford D, Reiche A, Dlubek G, Alloin F, Sanchez J-Y, Alam MA. Ionic conductivity, glass transition, and local free volume in poly (ethylene oxide) electrolytes: single and mixed ion conductors. J Chem Phys. 2003;118:9420–9432. doi: 10.1063/1.1567717. [Cross Ref]
16. Netti PA, Ambrosio L, Del Nobile MA, Mensitieri G, Nicolais L. Water transport in hyaluronic acid esters. J Bioact Compat Polym. 1996;11:312–316.

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