Divisability of diltiazem matrix sustained-release tablets

Area of Science:

• Pharmaceutical Sciences
• Drug Delivery Systems

Background:

• Sustained-release (SR) dosage forms are designed for controlled drug release over time.
• Tablet divisibility is a practical concern for dose adjustment, but can alter release profiles.

Purpose of the Study:

• To investigate whether dividing diltiazem hydrochloride SR tablets affects their drug release characteristics.
• To analyze the in vitro release kinetics and compare dissolution profiles before and after tablet division.

Main Methods:

• Diltiazem hydrochloride SR tablets with a groove were tested for dissolution.
• Dissolution parameters (t10%, t25%, t50%, dissolution efficiency) were evaluated using USP apparatus 4.
• Release kinetics were modeled using Higuchi, zero order, and Korsmeyer-Peppas, among others.
• Similarity factors (f1, f2) and Rescigno index assessed profile differences.

Main Results:

• Statistically significant differences in t10%, t25%, and t50% dissolution times were observed.
• The diltiazem release rate followed the Higuchi model, controlled by diffusion in a swelled polymeric matrix.
• Release rate was dependent on the contact area, not the matrix volume, suggesting division impacts release.

Conclusions:

• Tablet division significantly affects the drug release characteristics of diltiazem hydrochloride SR tablets.
• The diffusion-controlled release mechanism is altered upon tablet division.
• Care should be taken when dividing these SR tablets to maintain therapeutic efficacy.