Papaverine hydrochloride release from ethyl cellulose-walled microcapsules

Area of Science:

• Pharmaceutical Technology
• Drug Delivery Systems
• Materials Science

Background:

• Ethyl cellulose microcapsules are used for controlled drug release.
• Understanding release mechanisms is crucial for optimizing drug delivery.

Purpose of the Study:

• To investigate the papaverine hydrochloride release mechanism from ethyl cellulose microcapsules.
• To correlate microcapsule wall thickness and core:wall ratio with release kinetics.

Main Methods:

• Microencapsulation of papaverine hydrochloride using coacervation.
• In vitro release studies in simulated gastric and intestinal fluids.
• Analysis of release data using kinetic models.

Main Results:

• Thin-walled microcapsules ruptured in simulated gastric fluid due to osmotic pressure, suggesting dissolution-controlled release.
• Internal osmotic pressure caused minimal pore formation in thin-walled microcapsules in intestinal fluid.
• Thick-walled microcapsules exhibited diffusion-controlled release kinetics in both media without rupture.

Conclusions:

• Microcapsule wall thickness significantly influences the release mechanism.
• Internal osmotic pressure plays a key role in thin-walled microcapsule rupture and drug release.
• The core dissolution rate versus drug diffusion rate through the wall affects osmotic pressure development.