Comparison of Compressibility, Compactability, and Lubricant Sensitivity of Two Partially Pregelatinized Starches
Abstract
Modified starches are widely employed excipients in tablets compression. The ability of materials to deform under pressure (compressibility) and create strong compacts (compactability) is then important for tablet manufacture.
This study aims to evaluate and compare two partially pregelatinized starches, namely, Starch 1500 and Lycatab C, from the perspectives of compressibility, compactability, and lubricant sensitivity. Compressibility is evaluated by means of the compression energy profile and a stress relaxation test.
Compactability is evaluated by means of the tablets tensile strength, and lubricant sensitivity is characterized by the lubricant sensitivity ratio (LSR) values. The lubricants employed are magnesium stearate and sodium stearyl fumarate at concentrations of 0.5% and 1%, respectively.
In the case of the mixtures with 1% magnesium stearate, the influence of the mixing time is also evaluated. Starch 1500 shows better compressibility than Lycatab C due to its lower precompression and total energy values.
On the opposite, the plasticity is higher for Lycatab C. This material has also better compactability, yields stronger tablets, but has higher lubricant sensitivity than Starch 1500.
Different compressibility and compactability are found for Lycatab C and Starch 1500 and therefore, they cannot be easily interchanged in tablet manufacture.