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Sustained delivery of captopril from floating matrix tablets
Inéz Jiménez-Martínez1, Tomás Quirino-Barreda, Leopoldo Villafuerte-Robles
1Department of Biological Systems, Autonomous Metropolitan University-Xochimilco, Calzada del Hueso 1100, Col. Villa Quietud, C.P. 04960, D.F., Mexico.
International Journal of Pharmaceutics
|July 1, 2008
Summary
This study explored sustained release captopril tablets using Metolose SH 4000 SR and sodium bicarbonate. Tablet formulation and compaction pressure significantly influence floating time and drug release kinetics.
Area of Science:
- Pharmaceutical Technology
- Materials Science
Background:
- Developing controlled release formulations for captopril presents significant challenges.
- Floating tablet technology offers potential for extended drug release and improved therapeutic outcomes.
Purpose of the Study:
- To investigate the in vitro sustained release of captopril from Metolose SH 4000 SR/sodium bicarbonate floating tablets.
- To evaluate the impact of varying polymer proportions and compaction pressures on tablet properties and drug release.
Main Methods:
- Formulation of floating tablets with Metolose SH 4000 SR and sodium bicarbonate.
- In vitro dissolution studies to assess captopril release kinetics.
- Evaluation of tablet floating time, hydration volume, and density under different compaction pressures (55 MPa and 165 MPa).
Main Results:
- Tablets compacted at 55 MPa exhibited prolonged floating (>8h).
- Inclusion of sodium bicarbonate was essential for floating at 165 MPa.
- Increased polymer content enhanced hydration volume and release duration.
- Sodium bicarbonate inclusion reduced drug release, attributed to CO2 bubble interference with diffusion.
Conclusions:
- Tablet compaction pressure and formulation composition (Metolose SH 4000 SR, sodium bicarbonate) are critical factors for controlled captopril release.
- Floating tablet systems demonstrate potential for sustained drug delivery, with optimization needed for release rate modulation.
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