Relationships Between Tablet Physical Quality Parameters and Granulated Powder Properties: Feasibility Study

Abstract

This research was carried to study the feasibility of using mechanical properties of granulated powder formulations in low to medium pressure regime (<10 MPa) as predictors of tablet quality parameters. Mechanical properties of granulated powder formulations at three binder contents were determined using a flexible boundary cubical triaxial tester. Tablets formed at two pressures (70 and 90 MPa) were tested for four quality parameters, that is, diametral strength, axial penetration strength, indentation hardness, and friability. Some of the key findings were: bulk modulus, shear modulus, and spring-back index increased with pressure; binder had different effect on bulk modulus and compression index at different loading rates; at both loading rates, the spring-back index for 10% binder content was higher than for 5% binder content. In general, tablet hardness was highest without binder. Most of the powders’ properties related with tablet qualities, that is, had R² > 0.80; that is, demonstrating the feasibility of using powder properties as initial predictors of tablet quality for formulations tested. An elastic energy based hypothesis was proposed to provide a fundamental basis for mechanical properties of powder formulations versus tablet quality relationships. The positive outcome of this feasibility study suggests that the approach could be used for other pharmaceutical formulations.

Keywords:

• dimetral and axial strength
• elastic properties
• elastoplastic properties
• failure properties
• friability
• tablet quality prediction

Notes

BM = bulk modulus (GPa); CI = compression index; SI = spring-back index.

*DS₇₀ = 0.0003 BM_10,10 + 0.1174; DS₇₀ = diametral strength at 70 MPa compaction pressure; and BM_10,10 = bulk modulus at 10 MPa pressure and 10 MPa/min loading rate.