Nifedipine di-matrix depot tablets prepared by compression coating for obtaining zero-order release

Area of Science:

• Pharmaceutical Technology
• Drug Delivery Systems
• Polymer Science

Background:

• Achieving zero-order drug release is crucial for effective and consistent therapeutic outcomes.
• Compression coating offers a viable method for developing sustained-release dosage forms.
• Nifedipine, a calcium channel blocker, requires controlled release to manage conditions like hypertension.

Purpose of the Study:

• To develop and characterize nifedipine compression-coated (CC) di-matrix depot tablets for zero-order release.
• To investigate the in vitro release behavior and mechanisms of the developed CC tablets.
• To optimize the formulation for sustained nifedipine delivery over 24 hours.

Main Methods:

• Preparation of nifedipine CC tablets using a single punch tablet press.
• Utilized low viscosity hydroxypropyl cellulose (HPC-L) for the inner polymer and HPC-L, middle viscosity HPC-M, and Eudragit RSPO for outer polymers.
• In vitro release studies and gravimetric analysis were employed to determine release profiles and mechanisms.

Main Results:

• The optimized formulation achieved ideal zero-order release with a nifedipine ratio of 3:5 (core:layer).
• A specific combination of HPC-L and HPC-M (56:25) in the outer depot, with the core centrally placed, was critical.
• The CC tablets demonstrated over 95% release within 24 hours, fitting a zero-order kinetic model (R² = 0.98555).

Conclusions:

• Zero-order release of nifedipine over 24 hours is achievable using the compression coating technique.
• The combination of HPC-L and HPC-M polymers in the outer layer is effective for controlling nifedipine release.
• This approach offers a promising strategy for developing advanced sustained-release nifedipine formulations.