Evaluation of systemic exposure of nanoparticle suspensions subcutaneously administered to mice regarding stabilization, volume, location, concentration and size

Modulating target engagement of small molecules via drug delivery: approaches and applications in drug discovery and development

Drug-delivery technologies for modified drug release have been in existence for decades, but their utilization has been largely limited to post-launch efforts improving therapeutic outcomes. Recently, they have gained renewed importance because the pharmaceutical industry is steadily shifting to a more integrated discovery-development approach. In discovery, modulating target engagement via drug-delivery technologies can enable crucial pharmacological studies for building well-defined criteria for molecular design. In development, earlier implementation of delivery technologies can enhance the value of drug products through reduced dosing frequency and improved tolerability and/or safety profile, thereby leading to better adherence and therapeutic effectiveness.

Evaluation of preclinical formulations for a poorly water-soluble compound

One central aim of the present work was to find a robust oral formulation approach for Compound A, both to achieve reliable pharmacodynamic read outs but also for long time safety assessment studies. The compound has low aqueous solubility (0.4μM at 37°C), is highly lipophilic and has high Caco-2 permeability, i.e. a typical BCS II compound. A nanocrystal formulation, some oil approaches and a fat diet approach were evaluated in vivo in rats. The two latter strategies resulted in significantly higher in vivo exposures after oral administration compared to the nanocrystal approach. For simplicity, and due to the project development program, a food pellet formulation was selected. In addition, tentative data from a subcutaneous study in mice using nanocrystals of the compound are presented, showing extended profiles on the cost of Cmax. Exposure data in monkeys after administration of nanocrystals both intravenously and per oral are presented. When switched from nanocrystals to an oil formulation, the observed oral exposure behavior was similar as observed in rats.

Molecular interactions and solubilization of structurally related meso-porphyrin photosensitizers by amphiphilic block copolymers (Pluronics)

The influence of four Pluronics block copolymers (i.e. F68, P123, F127, and L44) on the aggregation and solubilization of five structurally related meso-tetraphenyl porphyrin photosensitizers (PS) as model compounds for use in Photodynamic Therapy of cancer (PDT) was evaluated. Interactions between the PSs and Pluronics were studied at micromolar concentration by means of UV-Vis absorption spectrometry and by kinematic viscosity (υ) and osmolarity measurements at millimolar concentrations. Pluronic micelles were characterized by size and zeta potential (ζ) measurements. The morphology of selected PS-Pluronic assemblies was studied by atomic force microscopy (AFM). While hydrophobic 5,10,15,20-Tetrakis(4-hydroxyphenyl) porphine (THPP) seemed to be solubilized in the Pluronic micellar cores, amphiphilic di(monoethanolammonium) meso-tetraphenyl porphine disulphonate (TPPS2a) was likely bound to the micellar palisade layer. Hydrophilic PSs like 5,10,15,20-Tetrakis (4-trimethylaniliniumphenyl) porphine (TAPP) seemed to form complexes with Pluronic unimers and to be distributed among the micellar coronas. TPPS2a aggregated into a network which could be broken at Pluronic concentration [Formula: see text] cmc, but would reconstitute in the presence of tonicity adjusting agents, e.g. sodium chloride (NaCl) or glucose.