Evaluation of a Dry Coating Technology as a Substitute for Roller Compaction for Dry Agglomeration Applications in the Pharmaceutical Industry

Abstract

A dry coating technology has been evaluated as a dry agglomeration technique for a typical pharmaceutical formulation. Its efficiency was compared with that of the more commonly used roller compaction dry granulation. A commercially available system was selected as a representative technology. The selection was based on batch size, processing time, unit size, vendor support, preventive maintenance requirements, development stage, and maturity for pharmaceutical industry requirements. The comparison targets the behavior of the resulting materials in terms of flowability, compressibility, mixing efficiency, and prevention of segregation. Particle size distribution, bulk density, scanning electron microscopy, FT4 powder rheometer, and hardness were used for the characterization of the powders. A design of experiment was used to evaluate the impact of the dry coating equipment operating parameters (rotor speed and processing time) as well as the impact of formulation (grade of microcrystalline cellulose and ratio between dibasic calcium phosphate and lactose). The tested dry coating technology shows (1) an improved compressibility, (2) that the powders are homogenous, and (3) that they do not have a tendency to segregate in downstream process steps and during handling and storage. The impact of the rotor speed is proven statistically not significant, but it seems that a lower rotor speed might lead to less attrition and better flow properties. Processing time does not seem to have an impact for the range of processing times evaluated. Compared to roller compaction, the main advantages of the tested technology are the shape and surface enhancement and the absence of work hardening. This work has shown that the blends produced by the targeted dry coating equipment has equal or better results than the powders processed by roller compaction for all the critical quality attributes that were evaluated.