Towards the Importance of a Roller Mill in Compounding Practice: An Experimental Approach

There are a substantial amount of suppliers for roller mills in the market, but there is a lack of scientific evidence of a roller mill's capacity to improve particle size reduction/distribution or homogenization. In this concise paper, we evaluate the use a roller mill in the final steps of compounding semisolid dosage forms. We performed three simple tests to verify these claims: 1) particle size evaluation through dynamic light scattering and scanning electron microscopy techniques, 2) content uniformity through high-performance liquid chromatography technique, and 3) cross contamination through a cleaning validation method. Dynamic light scattering and scanning electron microscopy techniques of benzoyl peroxide 5% (gel) and testosterone 1% (cream) showed a significant reduction on particle diameter. Content uniformity testing of creams containing progesterone 5%, estradiol 0.1%, and estriol 0.4% showed better homogeneity when using the roller mill. Finally, the proposed cleaning procedure decreased the presence of the compounded preparation to a "none-detection" level after the procedure. This suggests that the roller mill used does, in fact, play a role in the final aspect and quality of pharmaceutical semisolid dosage forms.