Usability of theophylline extended-release dry syrups

Abstract

Objectives We examined the usability of theophylline extended-release dry syrups, including their powder fluidity and ingestibility using one branded and six generic formulations (formulations A, B, C, D, E, F, and G, respectively). Methods To evaluate the ease of handling by pharmacists, powder fluidity was evaluated by measuring the repose angle, whereas to determine ingestibility, the viewpoints of patients or caregivers were evaluated using a questionnaire survey. Results and discussion: The repose angles of formulations A, B, C, D, E, and F were approximately 30°–40°. These formulations had sufficient powder fluidity, indicating the ease of weighing for most pharmacists. However, the repose angle of formulation G was <30°. Formulation G had high fluidity, suggesting its high rolling property. Thus, powder handling for formulation G may be more difficult than that for other six formulations. The ingestibility, such as the ease of mixing the dry syrup with water and odor intensity, was different between the formulations. Conclusions The present study provides useful information for selecting branded or generic theophylline extended-release dry syrups.