Oral Delivery Of PROTACs: Integrating Molecular Design And Enabling Formulation

Proteolysis targeting chimeras (PROTACs) offer a fundamentally different pharmacology from conventional occupancy-driven inhibitors by catalytically recruiting the ubiquitin-proteasome system to degrade intracellular targets. That promise, however, is paired with a difficult oral-delivery problem. PROTACs frequently occupy beyond-rule-of-five chemical space, where high molecular weight, elevated polarity, conformational flexibility, limited aqueous solubility, and transporter-mediated efflux can constrain intestinal absorption and systemic exposure.

The poster frames oral developability as a multivariable challenge rather than a single-property problem: molecular design, gastrointestinal dissolution, epithelial permeability, systemic pharmacokinetics, cellular uptake, and intracellular ternary-complex formation all influence whether an orally administered degrader can achieve meaningful target degradation. It also shows that formulation technologies can address different parts of this problem. Amorphous solid dispersions, including spray-dried dispersions and hot-melt extrudates, can enhance apparent solubility and supersaturation; lipid-based systems may improve solubilization and reduce precipitation; and other strategies such as salts, co-crystals, nanoparticles, permeation enhancers, and prodrugs may be useful for specific compound liabilities. No single technology solves every barrier.

The strongest development strategy therefore couples medicinal-chemistry optimization with biopharmaceutical understanding, custom in vitro testing, biomodeling, formulation design, and scalable process development. A white paper based on this material can position oral PROTAC development as an integrated design problem in which molecule and dosage form must be optimized together from the outset.