Formulation and optimization of polymeric agglomerates of Bosentan monohydrate by crystallo-co-agglomeration technique

Abstract

Abstract Background The polymeric spherical agglomerate of Bosentan monohydrate was prepared by crystallo-co-agglomeration technique, for enhancing the micrometric properties and solubility of the drug. The agglomerates were developed using two distinct solvents, DCM as a good solvent and bridging liquid and water as a weak solvent, respectively. Hydrophilic polymer like HPMC K100M is used as a hardening agent which gives mechanical strength to the agglomerates, and PEG6000 is used as a wetting agent. Other excipients like talc which was used as a size enhancer, and PVA was used as an emulsifier agent. The formulation was optimized by Box–Behnken design. The concentration of talc and PEG6000, as well as rotation speed, was considered as independent variables. The particle size, angle of repose, and % drug content were used as dependent variables to investigate the effect of independent variables on dependent variables. The spherical crystal agglomerates were subjected to various physicochemical evaluations. Results The results revealed that as the concentration of talc and PEG6000 increases, the sphericity and particle size of the agglomerates increase, and at a low agitation, speed agglomerates become more spherical and coarser, which is confirmed by FESEM. The characterization like FTIR confirms no interaction with excipients, while XRPD confirms the polymorphic changes, and gas chromatography (GC) confirms the concentration of residual organic solvents in PDE limits. The optimized formulation of SAs showed a good angle of repose which is 30.33 ± 0.35, and the % cumulative drug release at 20 min was 94.14 ± 0.628%. Finally, the FDTs of the optimized batch were prepared. Conclusions The comparison of the in vitro release study of pure drugs with agglomerates and fast dispersible tablets of agglomerates confirms the solubility improvement. Finally, it can be concluded that the polymorphic crystal agglomerates enhance the solubility and micrometric properties of Bosentan monohydrate.

Keywords

• Crystallo-co-agglomeration technique
• Spherical agglomerates
• Box–Behnken design
• In vitro drug release
• Gas chromatography