✦ LIBER ✦

Understanding the physical stability of freeze dried dosage forms from the glass transition temperature of the amorphous components

✍ Scribed by Shaun Fitzpatrick; Robert Saklatvala

Publisher: John Wiley and Sons
Year: 2003
Tongue: English
Weight: 150 KB
Volume: 92
Category: Article
ISSN: 0022-3549
DOI: 10.1002/jps.10474

No coin nor oath required. For personal study only.

✦ Synopsis

Modulated differential scanning calorimetry has been applied to understanding the long-term physical stability of freeze-dried units. It is known that these units are liable to contract on exposure to elevated temperature or humidity. The contraction occurs when the storage temperature is above the glass transition temperature of the amorphous components in the system. The effect of moisture content on the glass transition temperature of the amorphous components in the system has been studied. By combining this information with the moisture sorption isotherm it has been demonstrated that it is possible to predict the temperature and humidity conditions that will induce contraction of the unit. The magnitude of the glass transition temperature is composed of the contribution of each of the amorphous components in the system. It is proposed that it should be possible to develop a more robust system by the rational selection of excipients that increase the glass transition temperature or by modification of the processing conditions to promote crystallization of components that would otherwise depress the glass transition temperature.

📜 SIMILAR VOLUMES

Prediction of the onset of crystallizati

Prediction of the onset of crystallization of amorphous sucrose below the calorimetric glass transition temperature from correlations with mobility

✍ Chandan Bhugra; Shailaja Rambhatla; Aziz Bakri; Sarma P. Duddu; Danforth P. Mill 📂 Article 📅 2007 🏛 John Wiley and Sons 🌐 English ⚖ 183 KB

The objective of the present work is to determine if crystallization onset observed for an amorphous solid correlate with relaxation time at temperatures above and below the calorimetric glass transition (T g ). Crystallization onset of spray-dried and freeze-dried amorphous sucrose were measured ca

Characteristics of hydrogen bond formati

Characteristics of hydrogen bond formation between sugar and polymer in freeze-dried mixtures under different rehumidification conditions and its impact on the glass transition temperature

✍ Koreyoshi Imamura; Yoko Asano; Yoshinobu Maruyama; Tohru Yokoyama; Mayo Nomura; 📂 Article 📅 2008 🏛 John Wiley and Sons 🌐 English ⚖ 333 KB 👁 1 views

New theory on the physical properties of

New theory on the physical properties of polymers from cured resins to linear polymers: Melting temperature, glass-transition temperature, and strength

✍ Yahachiro Matsushita 📂 Article 📅 2005 🏛 John Wiley and Sons 🌐 English ⚖ 139 KB 👁 2 views

Solid-state stability of spray-dried ins

Solid-state stability of spray-dried insulin powder for inhalation: Chemical kinetics and structural relaxation modeling of Exubera above and below the glass transition temperature

✍ Negar Sadrzadeh; Danforth P. Miller; David Lechuga-Ballesteros; Nancy J. Harper; 📂 Article 📅 2010 🏛 John Wiley and Sons 🌐 English ⚖ 381 KB 👁 1 views

The effect of temperature on the chemical stability of an amorphous spray-dried insulin powder formulation (Exubera) 1 was evaluated in the solid state at constant moisture content. The chemical stability of the powder was assessed using reversed-phase high-performance liquid chromatography (RP-HPLC

Explanation of the crystallization rate

Explanation of the crystallization rate of amorphous nifedipine and phenobarbital from their molecular mobility as measured by 13C nuclear magnetic resonance relaxation time and the relaxation time obtained from the heating rate dependence of the glass transition temperature

✍ Yukio Aso; Sumie Yoshioka; Shigeo Kojima 📂 Article 📅 2001 🏛 John Wiley and Sons 🌐 English ⚖ 240 KB

To gain further insight into the effect of molecular mobility on the crystallization rate of amorphous drugs, the mean relaxation times of amorphous nifedipine and phenobarbital were calculated based on the Adam±Gibbs±Vogel (AGV) equation, using the parameters D, T 0 , and T f , derived from the hea