Development of SIMPATEC-USP: An abbreviated impactor for rapid testing of inhalation devices

Abstract

Cascade impactors like the Andersen Cascade Impactor (ACI) and Next Generation Impactor (NGI) are complex and costly due to multiple stages. This study introduces SIMPATEC-USP (Simplified Impactor Developed at the University of São Paulo), a low-cost, single-stage alternative meeting US Pharmacopeia standards for testing dry powder inhalers (DPIs). SIMPATEC-USP simplifies particle retention into a single Petri dish stage, eliminating multi-stage complexity. Its design includes a straightforward closure system for easy assembly/disassembly. A collection chamber holds a glass Petri dish with filter paper for final filtration, ensuring efficient aerosol product collection. SIMPATEC-USP also offers potential use with culture media for applications like antibacterial screening. Operating at 30 L/min, SIMPATEC-USP consists of three parts: a single-stage chamber, an L-shaped tube mimicking the trachea, and a vacuum pump. Aerosol particles are deposited onto the Petri dish via a nozzle, and the collected sample is weighed to determine drug concentration. Tested with inhalation-grade lactose, SIMPATEC-USP effectively collects and analyzes particles, allowing for rapid aerodynamic comparison of formulations, capsule retention assessment, and sample collection for drug release studies. The results demonstrate that it is possible to evaluate the performance of three inhalation devices regarding the mass migrating to the collection plate and that retained within the device itself. In conclusion, SIMPATEC-USP is highly suitable for exploratory studies and educational activities in pharmaceutical technology and pulmonary drug delivery systems.