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Updated: Jun 10, 2026
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Formation of Dispersible Taohong Siwu Tablets
Published on: February 3, 2023
Development and Optimization of a Biphasic-Release Acetazolamide Tablet-in-Tablet Formulation.
Si-Kai Wang1,2, Wei Li1,2, Miao-Miao Guo3
1School of Pharmacy, Hubei University of Chinese Medicine, Wuhan, 430065, China.
Drugs in R&D
|June 9, 2026
Summary
A novel acetazolamide (ACZ) tablet-in-tablet formulation offers both immediate and extended release for high-altitude illness (HAI) prevention. This biphasic delivery system aims to improve upon existing ACZ options.
Area of Science:
- Pharmaceutical Sciences
- Drug Delivery Systems
- High-Altitude Medicine
Background:
- High-altitude illness (HAI) presents significant health risks.
- Acetazolamide (ACZ) is the sole FDA-approved prophylactic medication for HAI.
- Current ACZ formulations (immediate-release and extended-release) have limitations in providing both rapid onset and sustained drug availability.
Purpose of the Study:
- To develop and characterize a biphasic-release acetazolamide tablet-in-tablet (ACZ-TIT) formulation.
- To create a proof-of-concept oral dosage form integrating immediate-release (IR) and extended-release (ER) properties.
- To assess the potential of ACZ-TIT to overcome limitations of existing ACZ delivery systems.
Main Methods:
- Excipient compatibility assessed using FTIR, DSC, and PXRD.
- Solubility evaluated in relevant physiological media.
- Formulation optimized using single-factor studies and response surface methodology (RSM).
- In vitro dissolution studies and drug release kinetic analysis (Ritger-Peppas model).
Main Results:
- ACZ-TIT demonstrated a biphasic release profile: 25.3% at 0.5 h and 86.5% at 10 h.
- Physical properties met pharmacopeial standards, with no significant ACZ-excipient incompatibilities observed.
- Release kinetics best fit the Ritger-Peppas model, indicating diffusion-controlled extended release.
Conclusions:
- The developed ACZ-TIT formulation shows promise for providing rapid initial drug release followed by sustained exposure.
- This biphasic delivery could address shortcomings of current acetazolamide dosage forms for HAI prophylaxis.
- Further in vivo pharmacokinetic and clinical studies are necessary to confirm clinical utility.
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