Dissolution of fludrocortisone from phospholipid coprecipitates

Area of Science:

• Pharmaceutical Sciences
• Materials Science
• Physical Chemistry

Background:

• Fludrocortisone acetate (FA) is a poorly water-soluble drug.
• Improving the dissolution of such drugs is crucial for enhancing bioavailability.
• Phospholipid coprecipitates offer a potential strategy for drug delivery.

Purpose of the Study:

• To investigate the physical properties and dissolution behavior of fludrocortisone acetate (FA) phospholipid coprecipitates.
• To evaluate the impact of added polymers on the dissolution characteristics of these coprecipitates.
• To explore the potential for controlled drug release using these formulations.

Main Methods:

• Preparation of phospholipid coprecipitates of FA with dimyristoyl phosphatidylcholine (DMPC).
• Dissolution testing at pH 2.0 and 37°C to determine fraction dissolved and initial dissolution rate (IDR).
• Differential thermal analysis (DTA) to assess thermal properties.
• Kinetic modeling (second-order, Weibull distribution) to describe dissolution.

Main Results:

• FA:DMPC coprecipitates (4:1, w/w) showed a 77% fraction dissolved and a 3.5-fold greater IDR compared to FA alone.
• No aging effects were observed over 4 months.
• Dextran and poly(lactic acid) reduced dissolution, while poly(vinylpyrrolidone) (PVP) showed varied effects depending on molecular weight and concentration.
• PVP 24 specifically influenced melting point and heat of fusion.

Conclusions:

• High drug-loading solid dispersions using phospholipids effectively enhance the dissolution of poorly water-soluble drugs like FA.
• Incorporation of specific polymers can modulate drug release kinetics.
• These findings support the use of phospholipid coprecipitates for improved drug delivery and controlled release applications.