Stability of extruded 17 beta-estradiol solid dispersions

Area of Science:

• Pharmaceutical Science
• Materials Science

Background:

• Recrystallization poses a significant challenge to the stability of solid dispersions.
• 17 beta-Estradiol is a model drug frequently used in pharmaceutical formulations.

Purpose of the Study:

• To evaluate the recrystallization stability of melt-extruded solid dispersions containing 17 beta-Estradiol.
• To assess the impact of excipient selection on the stability of these solid dispersions.
• To confirm the long-term stability of 17 beta-Estradiol solid dispersion tablets under accelerated conditions.

Main Methods:

• Melt extrusion technique for solid dispersion preparation.
• Differential Scanning Calorimetry (DSC) for thermal stability assessment.
• Isothermal microcalorimetry and moisture absorption gravimetry for water vapor stability.
• United States Pharmacopeia (USP) dissolution testing for drug release.

Main Results:

• No recrystallization was observed in melt-extruded solid dispersions of 17 beta-Estradiol after treatment with heat or water vapor.
• DSC analysis indicated excellent thermal stability by showing no change in glass transition temperature.
• Solid dispersions demonstrated robust stability against water vapor, confirmed by isothermal microcalorimetry and moisture absorption studies.
• Estradiol tablets maintained drug release profiles, meeting USP 23 standards after 6 months of accelerated storage (40°C/75% RH).

Conclusions:

• Careful selection of excipients, including polymers and additives, is crucial for enhancing the stability of solid dispersions.
• Melt-extruded solid dispersions of 17 beta-Estradiol exhibit superior stability against thermal stress and humidity.
• The developed solid dispersions are suitable for pharmaceutical applications, ensuring long-term drug product quality and efficacy.