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Controlled-release tablets from carrageenans: effect of formulation, storage and dissolution factors
V K Gupta1, M Hariharan, T A Wheatley
1University of Georgia, College of Pharmacy, Department of Pharmaceutical and Biomedical Sciences, Athens, GA, USA. vishal.k.gupta@pharmacia.com
Summary
Carrageenan tablets offer reliable controlled drug release, showing minimal sensitivity to formulation changes and storage conditions. This makes them a promising excipient for developing stable, predictable oral dosage forms.
Area of Science:
- Pharmaceutical Technology
- Materials Science
Background:
- Carrageenans are widely used hydrocolloids with potential applications in drug delivery.
- Developing controlled-release formulations requires careful selection of excipients to ensure consistent drug release profiles.
Purpose of the Study:
- To evaluate the suitability of iota-carrageenan and lambda-carrageenan for creating controlled-release theophylline tablets.
- To investigate the impact of various formulation and environmental factors on drug release kinetics.
Main Methods:
- Tablets containing theophylline were prepared using iota- and lambda-carrageenan via compression.
- Theophylline release was measured under varying conditions, including drug-to-carrageenan ratio, tablet dimensions, and dissolution media ionic strength.
- The influence of moisture, storage (37°C/75% RH for 3 months), and sodium chloride incorporation was assessed.
Main Results:
- Drug release rate positively correlated with tablet diameter and drug-to-carrageenan ratio.
- Lubricants showed negligible impact on drug release at typical concentrations.
- Moisture, prolonged storage, and 10% sodium chloride inclusion did not significantly alter release rates.
- Altered ionic strength of simulated gastric fluid affected release, while simulated intestinal fluid did not.
Conclusions:
- Carrageenan-based tablets demonstrate robustness and relative insensitivity to minor variations in formulation and dissolution conditions.
- These findings support the use of carrageenans as reliable excipients for developing stable controlled-release drug delivery systems.
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