Preparation of biodegradable poly(+/-)lactide microparticles using a spray-drying technique.

Area of Science:

• Materials Science
• Pharmaceutical Technology
• Polymer Chemistry

Background:

• Biodegradable polymers like poly(lactide) are crucial for controlled drug delivery.
• Traditional microencapsulation methods often face limitations based on drug solubility.
• Spray-drying offers a potential alternative for microparticle formulation.

Purpose of the Study:

• To prepare biodegradable poly(lactide) microparticles using spray-drying.
• To evaluate the influence of drug state (dissolved vs. dispersed) on microparticle formation.
• To characterize the drug release profiles from the prepared microparticles.

Main Methods:

• Spray-drying technique for microparticle preparation.
• Incorporation of model drugs (progesterone, theophylline) in dissolved or dispersed states.
• Characterization using Differential Scanning Calorimetry (DSC) and Scanning Electron Microscopy (SEM).
• Analysis of drug release kinetics.

Main Results:

• Spray-drying demonstrated reduced dependence on drug solubility compared to phase separation or solvent evaporation.
• Microparticles exhibited a biphasic drug release pattern: an initial burst release followed by sustained release.
• The extent of both release phases was influenced by the drug loading concentration.

Conclusions:

• Spray-drying is a viable and flexible method for creating poly(lactide) microparticles for drug delivery.
• The observed drug release profile suggests potential for tailored release kinetics based on formulation parameters.
• This technique holds promise for developing advanced drug delivery systems with tunable release characteristics.