Methods of Reducing Particle Formation Keeping Protein Drugs Clear and Stable in the Vial

This patent describes ways to formulate protein-based medicines so that fewer tiny particles form in the vial during manufacture and storage. It comes from Regeneron Pharmaceuticals, Inc., a large American biotechnology company known for its antibody drugs.

The Problem

Many modern medicines are proteins, such as monoclonal antibodies, that must stay dissolved and intact from the factory to the patient. Over time, and especially under stress from shaking, temperature swings, or contact with container surfaces, protein molecules can clump together and form subvisible particles. These particles are a serious quality problem: they can reduce a drug’s potency and, in the worst case, provoke an unwanted immune reaction. Formulators add surfactants such as polysorbate to protect the protein, but these stabilisers are themselves mixtures that can degrade and, ironically, seed new particles. The challenge is to keep the protein protected without introducing impurities that make the particle problem worse.

What This Invention Does

The invention provides biopharmaceutical compositions and drug products that show reduced subvisible particle formation, along with methods for preparing and storing them. The key move is in the choice of stabiliser: the compositions include a protein together with a surfactant or stabiliser made up of a high proportion, for example at least 97 percent, of a long-chain fatty acid ester. By using a stabiliser that is highly enriched in the desired long-chain ester rather than a broader mix, the formulation avoids the minor components that tend to break down and trigger clumping. The patent also covers the methods of making and storing these compositions, so the protection spans both the recipe and the process that keeps the finished drug clear and stable through its shelf life.

Key Features

• Reduced subvisible particles. The compositions are designed to form fewer of the tiny particles that compromise protein drug quality.
• High-purity stabiliser. The surfactant or stabiliser is enriched, for example to at least 97 percent, in a long-chain fatty acid ester.
• Fewer degradation triggers. Cutting the minor components of the stabiliser removes impurities that can seed protein clumping.
• Covers preparation and storage. The claims include methods for making and storing the compositions, not just the finished formula.
• Broadly applicable. The approach suits protein and antibody drug products that rely on surfactant protection.

Who Is Behind It

The applicant is Regeneron Pharmaceuticals, Inc., a biotechnology company based in New York State that develops and manufactures antibody medicines for eye disease, inflammation, cancer, and other conditions. The named inventors include Mayank Patel, Stacy Wasinger, Danya Spritzer, and Xiaolin Tang. This filing is a divisional application from an earlier related Australian application.

Why It Matters

Protein and antibody drugs are among the most valuable and fastest-growing medicines, and regulators scrutinise particle levels closely because of the safety and potency risks they carry. A formulation strategy that keeps subvisible particles low across a product’s shelf life improves reliability and reduces the chance of batches being rejected. Protecting this approach in Australia supports the supply of stable biopharmaceutical products in a tightly regulated market.

Related Concepts

• Monoclonal antibody – a major class of protein drug this formulation protects.
• Protein aggregation – the clumping process that creates unwanted particles.
• Surfactant – the stabiliser type whose purity this invention improves.
• Polysorbate – a common surfactant family used in protein formulations.
• Biopharmaceutical – the category of protein-based medicines involved.

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AU 2026202007 was published in the Australian Official Journal of Patents on 2 April 2026 and is open for public inspection. Patent applications represent inventions that are sought to be protected and do not necessarily reflect commercially available products.