Development of novel coprocessing technique for ethambutol hydrochloride to improve its processability

Abstract

Active pharmaceutical ingredient (API) coprocessing technique such as quasi-emulsion solvent diffusion (QESD) is gaining prominence as an alternative to granulation for improving powder flowability and tablet manufacturability. Current research provides a novel methodology to coprocess ethambutol hydrochloride (ETB) with HPMC-E polymer to obtain spherical agglomerates. Different HPMC-E polymer grades (E5, E15 and E50) were used at different concentrations (1 %w/v, 2.5 %w/v, and 5 %w/v) to assess its impact on the coprocessing. All coprocessed QESD samples performed significantly better than ETB-API in terms of flowability improvement by angle of repose (p < 0.01), Carr's index (p < 0.05). PXRD, DSC, and FTIR analyses indicated no solid-state changes in coprocessed ETB. The QESD samples could be compacted into tablets of sufficient tensile strength (>1.7 MPa) by direct compression method. Though intrinsic dissolution rate was lower for coprocessed API, tablet dissolution studies revealed no effect on the dissolution profile with ∼95 % of ETB dissolution within 30 mins of the study. © 2025 Elsevier B.V.