Rivastigmine hydrogen tartrate

Salatin S, et al. Colloids and Surfaces B: Biointerfaces, 2017, 159, 629-638.

Rivastigmine hydrogen tartrate (RHT) was encapsulated in PLGA nanoparticles (NPs) using nanoprecipitation followed by solvent displacement, testing polymer-to-drug ratios of 5:1, 7:1, and 9:1. RHT (10 mg) was dissolved in water and combined with PLGA in acetone to form the organic phase, subsequently added to a 2% w/v aqueous poloxamer 407 solution under stirring (400 rpm). The solvent was evaporated for 2 h at room temperature, and NPs were centrifuged at 18,500g for 60 min at 4 °C, washed thrice to remove unencapsulated drug, and lyophilized without cryoprotectants. Resulting RHT-loaded PLGA NPs were embedded in P407 gel matrices and characterized for viscosity, gelation temperature, stability, mucoadhesive behavior, and drug-loading efficiency, demonstrating a robust platform for sustained RHT delivery.

Simon A, et al. International Journal of Pharmaceutics, 2016, 501, 1-2, 124-138.

This study focused on the preparation and characterization of rivastigmine hydrogen tartrate (RHT) engineered microparticles for potential pulmonary delivery. Lactose carrier-free (LCF) formulations were spray-dried from 1% (w/v) solutions of RHT, inulin, and l-leucine in 30% ethanol:water at 40 °C to ensure solubilization of inulin, with 0.2% fluorescein sodium salt incorporated for NGI deposition quantification without altering powder morphology. For comparison, a conventional lactose carrier formulation was prepared using α-lactose monohydrate (median diameter 40 µm) and micronized RHT (d50 2 µm) blended at 7.5%:92.5% w/w in a Turbula® shaker-mixer for 1 h. Powder homogeneity was confirmed by HPLC (RSD < 5%). These methodologies enabled detailed evaluation of physicochemical and aerodynamic properties, demonstrating the feasibility of RHT microparticles in dry powder inhalation systems, with spray drying and carrier selection critically influencing particle characteristics and deposition performance.