Physical aging in pharmaceutical polymers and the effect on solid oral dosage form stability

• Published in: International journal of pharmaceutics Vol. 457; no. 2; pp. 428 - 436
• Main Authors: Kucera, Shawn A., Felton, Linda A., McGinity, James W.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 05.12.2013
• Subjects: analytical methods; Chemistry Techniques, Analytical; dispersions; Dosage Forms; drug formulations; Drug Stability; drugs; Film coating; humidity; oral administration; permeability; Pharmaceutical Preparations - chemistry; Physical aging; Polymers; Polymers - chemistry; Stability; temperature; thermodynamics; Film coating; Stability; Physical aging; Polymers
• ISSN: 0378-5173; 1873-3476; 1873-3476
• DOI: 10.1016/j.ijpharm.2013.01.069

The application of a polymeric film to a solid oral dosage form can be an effective technique to modify drug release. Most polymers used for such purposes are amorphous in nature and are subject to physical aging. This physical aging phenomenon has been shown to cause changes not only in the mechanical and drug release properties of polymeric films, but also the permeability of these films due to a densification and decrease in free volume of the polymer as the material relaxes to an equilibrated thermodynamic state. Temperature, humidity, and additional excipients in the coating formulations have been shown to influence the aging process. This review article discusses the process of physical aging in films prepared from aqueous dispersions, describes various analytical techniques that can be used to investigate the aging process, and highlights strategies to prevent such aging.