Impact of binder as a formulation variable on the material and tableting properties of developed co-processed excipients

Abstract

The functionality of a co-processed excipient is usually derived from its composition and the proportion of each excipient that is incorporated to yield a composite excipient. The aim of this study was to assess the impact of binder as a formulation variable on the material and tableting properties of developed co-processed excipients containing gelatin (SGS) and microcrystalline cellulose (SMS) as binders respectively in the same proportion. Two co-processed excipients, SGS and SMS were generated by combining tapioca starch (90%), gelatin or microcrystalline cellulose (7.5%) and colloidal silicon dioxide (2.5%) using the co-fusion method. Particle size analysis and morphological assessment were carried out by light microscopy and scanning electron microscopy (SEM) respectively. DSC analysis was performed to evaluate the thermal behaviour of both materials and flow properties were assessed by measuring parameters like angle of repose, bulk and tapped densities, Carr’s index and Hausner’s ratio. Compaction behaviour of both materials was determined using Heckel and Walker equations and the compressibility–tabletability–compactibility (CTC) profile for each material was obtained. Particulate and bulk-level properties of SGS and SMS revealed spherical-shaped, free-flowing powders characterized by a glass transition event typical of amorphous polymers. Compaction analysis demonstrated greater degree of plastic deformation with SMS resulting in better tableting properties with respect to tensile strength and disintegration time.The outcome of the study shows that the choice of binder used in the formulation of a co-processed excipient plays a crucial role in defining the material and tableting properties of the co-processed excipient.