Glassy Surfactants Enable Ultra-High Concentration Biologic Therapeutics

Protein therapeutics, like peptides and antibodies, have become critical to healthcare. Despite their exceptional potency and specificity, biopharmaceuticals are prone to aggregation, often necessitating low formulation concentrations as well as cold storage and distribution to maintain stability. Yet, high doses are required to treat many diseases. To achieve these doses, most approved protein drug products are administered intravenously, imposing excessive burdens on patients and the healthcare system. New approaches are needed to formulate proteins at high concentrations to enable less burdensome subcutaneous injection, preferably in an autoinjector format. To address this challenge, we report a subcutaneously injectable biotherapeutic delivery platform composed of spray-dried protein microparticles suspended in a non-solvent liquid carrier. These microparticles contain only active biopharmaceutical agent and a high glass transition temperature polyacrylamide-derived copolymer excipient affording several key benefits over traditional excipients, including: (i) improved stabilization of biopharmaceuticals through the spray drying process, and (ii) improved morphology and properties of the spray-dried particles, enhancing suspension injectability. Experiments with albumin and human IgG demonstrate that this technology enables ultra-high-concentration protein formulations (exceeding 500 mg/mL) that are injectable through standard needles with clinically relevant injection forces. Additionally, experiments in mice show these ultra-high-concentration formulations reduce required injection volumes without altering pharmacokinetics. This approach could double the number of commercial protein drugs amenable to subcutaneous administration, dramatically reducing burden and improving access to these critical biopharmaceuticals.