Understanding real-time water penetration dynamics in tablets using synchrotron X-ray micro-computed tomography

Area of Science:

• Pharmaceutical Sciences
• Materials Science
• Biophysics

Background:

• Understanding water penetration into pharmaceutical tablets is crucial for drug bioavailability.
• The microstructural mechanisms governing initial water uptake remain poorly understood.

Purpose of the Study:

• To visualize and quantify microstructural changes in tablets during water penetration.
• To elucidate the role of common pharmaceutical excipients in water penetration dynamics.

Main Methods:

• In-situ synchrotron X-ray micro-computed tomography (X-ray μCT) was employed.
• Tablets composed of microcrystalline cellulose (MCC), magnesium stearate (MgSt), di-calcium phosphate (DCP), and croscarmellose sodium (CCS) were analyzed.

Main Results:

• Magnesium stearate (MgSt) hydrophobicity significantly impeded water penetration in microcrystalline cellulose (MCC) tablets.
• Combining swelling MCC with rigid di-calcium phosphate (DCP) accelerated water penetration due to synergistic pore expansion.
• Croscarmellose sodium (CCS) induced rapid fragmentation and high porosity (<3 seconds).

Conclusions:

• Tablet water penetration is governed by diverse and synergistic mechanisms, including excipient swelling, rigidity, and fragmentation.
• Excipient properties critically influence water penetration dynamics and pore network stability.
• These insights are vital for designing oral solid dosage forms with improved drug bioavailability.