Sieve cuts as monodisperse powders in dissolution studies

Area of Science:

• Pharmaceutical Sciences
• Physical Chemistry
• Materials Science

Background:

• Accurate dissolution profiling is crucial for drug development and quality control.
• The cube root law is a common model for predicting dissolution from spherical particles.
• Sieve cuts are often used to approximate monosized powders in dissolution studies.

Purpose of the Study:

• To calculate dissolution profiles for sieve cuts of varying widths.
• To assess deviations from the cube root law based on particle size distribution.
• To determine the acceptability of using sieve cuts as monosized powders in dissolution testing.

Main Methods:

• Derived an equation for diffusion rate-limited dissolution under sink conditions.
• Calculated dissolution profiles for spherical particles within sieve cuts.
• Analyzed the impact of particle size distribution on deviations from the cube root law.

Main Results:

• Even narrow sieve cuts can show up to 3% deviation from cube root law expectations.
• Deviations are smaller when the weight distribution of particle diameters is constant across a sieve cut.
• Errors are generally acceptable when treating sieve cuts as monosized powders, except for critical dissolution rate theory tests.

Conclusions:

• Particle size distribution within sieve cuts influences dissolution profiles.
• Treating sieve cuts as monosized powders introduces acceptable errors for most applications.
• Further information on powder distribution is necessary for critical dissolution rate theory evaluations.