Investigating Granule Compression Dynamics: A Heckel Plot Approach to Optimize Crushing Strength in Tablet Formulations

Tablet manufacturing is a pivotal process in the pharmaceutical industry, where granule behaviour under compression significantly influences the mechanical properties and therapeutic efficacy of the final product. This study investigates the deformation behaviour of granules, the role of porosity, and the application of the Heckel equation in understanding tablet properties. Using hydroxypropyl methylcellulose (HPMC), ethyl cellulose (EC), lactose, and two different binders—starch (F1) and PVP K30 (F2)—tablets were prepared via the wet granulation method and compressed at various forces (65–85 kN). Tablet porosity was calculated from physical parameters such as thickness, diameter, and true density, and Heckel plots were constructed by plotting compressional force against the logarithm of the inverse of porosity (Log E-1). Analysis of the Heckel plots revealed that the crushing strength of F2 tablets was greater due to the higher slope (0.003) compared to F1 (0.002), indicating enhanced plastic deformation and stronger interparticle bonding with PVP K30 as the binder. Conversely, the larger intercept value for F1 (-0.143) indicated higher initial porosity compared to F2 (-0.241). This study provides valuable insights into the role of binders and formulation parameters on tablet strength and porosity, enabling optimization of the compression process for improved pharmaceutical product quality.