Matrix polymeric excipients: comparing a novel interpolyelectrolyte complex with hydroxypropylmethylcellulose

Area of Science:

• Pharmaceutical Sciences
• Polymer Science

Background:

• Hydrophilic polymers like hydroxypropylmethylcellulose are widely used in monolithic matrix systems for controlled drug release.
• Chitosan and polycarbophil can form interpolyelectrolyte complexes with potential applications in drug delivery.

Purpose of the Study:

• To compare the in vitro dissolution, swelling, and erosion behavior of hydroxypropylmethylcellulose (HPMC) matrix systems with those containing a chitosan-polycarbophil interpolyelectrolyte complex.
• To evaluate the drug release mechanisms and kinetics from these two types of matrix systems.

Main Methods:

• Preparation of monolithic matrix tablets containing either HPMC or a chitosan-polycarbophil complex.
• In vitro dissolution, swelling, and erosion studies were conducted.
• Kinetic analysis of drug release profiles was performed.

Main Results:

• Both matrix systems exhibited a combination of swelling and erosion as drug release mechanisms.
• Matrix systems containing the chitosan-polycarbophil complex showed higher mean dissolution times, indicating slower drug release compared to HPMC systems.
• Zero-order release kinetics were approached for some formulations with the chitosan-polycarbophil complex, but not for HPMC formulations.

Conclusions:

• The chitosan-polycarbophil interpolyelectrolyte complex is a promising alternative to HPMC for developing monolithic matrix systems with controlled drug release properties.
• The observed slower drug release and potential for zero-order kinetics from chitosan-polycarbophil matrices offer advantages for optimizing drug delivery profiles.