Partnership Due Diligence Checklist for Peptide Therapeutic Companies With Two or More Decades of Nanoparticle Delivery Patents

For a peptide therapeutic company with 20-plus years of nanoparticle delivery patents, partnership diligence should start with the estate’s depth and defensibility. The same test should be used for a proposed university nanoparticle IP platform for peptide delivery. Its value depends on live claims, credible delivery science, and protection that extends beyond one molecule, while manufacturing and regulatory readiness determine how a partnership should proceed.

Why peptide therapeutic partnerships are structuring around delivery IP, not pipeline stage

GLP-1 receptor agonists are approved for type 2 diabetes and obesity, yet a majority of patients without type 2 diabetes who start injectable GLP-1 therapy discontinue within the first year. Clinical promise and sustained use are diverging. Research into addiction and dementia brings that tension to neurological indications, where getting enough of the drug into the brain is also a hurdle for delivery. Discontinuation makes delivery and adherence central partnership questions.

That tension revalues control over administration. AstraZeneca committed billions of dollars, including a substantial upfront payment, to CSPC Pharmaceutical Group for access to its LiquidGel once-monthly injectable dosing platform and an AI-driven peptide discovery platform for weight management. The platform was part of the acquisition logic. Moving a pipeline forward alone cannot give a company that control over delivery.

What 20-plus years of nanoparticle delivery patents actually signals to a due diligence team

A nanoparticle platform is a modular architecture. Its estate can accumulate protection across formulation design, surface functionalization, cargo encapsulation, and route-specific administration. Each generation can protect another part of the system. Two decades of filings therefore raise a useful question about whether successive inventions have deepened the platform or merely added disconnected formulations.

Age alone does not answer that question. Early patents may have expired, exposing designs that others can now practice, while later families may protect improvements built on that foundation. An estate with live claims and new inventions shows that invention continues beyond the work covered by older patents. It also supplies the history needed to examine freedom to operate, although longevity itself does not establish that freedom. The informative signal is the relationship between generations of claims.

Step 1 — Mapping the patent estate: claims coverage, family structure, and white space

In a platform estate, core nanoparticle parameters are linked to delivery routes, cargo classes, and administration devices. A collection of one-off patents may protect individual formulations without connecting them. For partners, the first task is to map those relationships before judging individual claims. The map should distinguish particle architecture, surface chemistry, formulation vehicles, and route-specific administration, including olfactory versus trigeminal deposition.

Hakim et al. (2026) illustrate four potential claim layers through their gemini surfactant-phospholipid nanoparticle formulation. These are composition, particle size and charge, cell-adhesion peptide surface functionalization, and cargo-specific encapsulation optimization. Conejos-Sánchez et al. (2026) provide a further layer through a depot-forming hydrogel vehicle that prolongs nasal residence. Partners should compare the estate’s actual claims with the parameters that make each formulation work.

GLP-1, GLP-2, neuropeptides, and growth factors may be explicitly claimed or covered only through broad genus language. That distinction separates a clear extension right from an opportunity requiring further freedom-to-operate work. Device coverage also belongs on the map, because actuator geometry, droplet size, and deposition targeting can leave administration exposed even when formulation chemistry is protected.

Step 2 — Evaluating claim defensibility: breadth, specificity, and prosecution history

Does a claim cover enough design space to deter alternatives without reaching beyond what the invention supports? Prior art can put broad composition claims at risk, while narrow claims can be easier to design around. Patent count cannot resolve this tension for partners. Partners should assess whether protection follows the commercially operative formulation, an abstract concept, or a peripheral variation.

Partners should check the prosecution history for amendments that gave up scope to avoid foundational nanoparticle literature, much of which was already in place by the early 2000s. What remains after those amendments may be much narrower than the original application suggests. Partners should also check dependent claims because they can protect specific working embodiments even when broader claims fail, as long as those narrower claims remain valid.

Hakim’s study illustrates why quantitative specificity need not mean weak commercial protection. Its optimal drug loading was constrained to a particular concentration range, suggesting that useful formulations may occupy a narrow parameter space. Partners should check whether precise claims protect that space. Conversely, broad treatment language unsupported by enabling formulation detail should not be mistaken for a defensible delivery platform.

Step 3 — Assessing scientific validity of the platform claims through the peer-reviewed delivery literature

A patent establishes neither transport efficiency nor clinical usefulness. Partners should seek mechanistic data that show how each claimed design feature works with the proposed delivery route. The olfactory pathway links olfactory epithelium to the olfactory bulb and onward brain regions, while the trigeminal pathway connects respiratory epithelium to the brainstem. Otherwise, the estate may protect a formulation without substantiating its central delivery premise.

Hakim’s study demonstrated higher CNS drug concentrations in mice after intranasal nanoparticle administration than after oral administration at a much lower dose, with a direct transport percentage of 73.5%, providing a comparator. Its cargo was IRX4204, so the result does not validate peptide delivery by another platform. Conejos-Sánchez’s study offers a separate mechanistic comparator, showing prolonged nasal residence and increased total brain accumulation with a polypeptide-based hybrid nanocarrier and hyaluronic acid hydrogel.

In the data room, partners should ask whether claimed particle sizes have support for the proposed transport pathway. They should also seek evidence connecting surface functionalization to transport enhancement and encapsulation and release kinetics to sustained CNS exposure. Human relevance requires an additional test. Humans have a smaller proportion of nasal surface devoted to olfactory epithelium than rodents, so standard rodent findings alone cannot establish achievable human brain concentrations.

Step 4 — Auditing the formulation and manufacturing IP for CMC-stage defensibility

Strong composition claims can coexist with thin manufacturing protection. This distinction deserves particular attention in academic spinouts, where foundational science may be deeper than process and device development. Chemistry, manufacturing, and controls diligence should examine protection for synthesis, particle formation, encapsulation, and nasal fill-finish. A protected formulation is not automatically a scalable product.

Intranasal peptide formulations must retain particle size distribution, encapsulation integrity, and peptide activity across shelf life. U.S. Patent 10,736,843 claims an in situ gelling composition using tocopherol-loaded micelles for intranasal delivery, illustrating a separately protectable formulation component. Partners should seek analogous protection where stability depends on excipient systems or storage conditions. Hakim’s stability characterization also supplies relevant scientific comparators through dynamic light scattering, TEM, and SAXS.

The audit should then examine controls for peptide degradation products and nanoparticle byproducts under evolving FDA guidance on peptide impurity qualification. Missing process claims can expose an underdeveloped CMC IP strategy. The review should also cover device protection, because an actuator designed for olfactory deposition controls a key part of how the drug is given. Vertically integrated protection connects the formulation to its reproducible manufacture and intended delivery.

Step 5 — Evaluating indication extensibility: how platform IP enables expansion beyond the lead peptide

Partners should map the cargo classes that claims protect against related indications and separate what the claims clearly cover from what their wording leaves in doubt. A claim to a GLP-1 receptor agonist may cover exendin-4 analogs without necessarily covering longer-acting GLP-1/GIP co-agonists. The distinction changes what the partnership actually controls.

Scientific rationale provides a second, separate test of that option. GLP-1 receptor expression in the hippocampus and cortex supports investigation of neurological uses, while its involvement in the mesolimbic reward system supports interest in addiction. UCSF is investigating brenipatide as a potential treatment targeting core brain mechanisms that frequently trigger relapse. That investment makes addiction a credible adjacency to examine.

Broader delivery literature also provides a way to test cargo scope against peptides beyond the lead asset, including insulin, GLP-2, growth factors, oxytocin, and neuropeptide Y. Coverage alone does not establish interchangeable formulation performance. Even with a broad patent, clinical validation is still needed. The option has value when rights to extend the platform can be defended and the delivery mechanisms have support, but each added cargo still needs work to become a product.

Step 6 — Which team and institution stand behind the patents?

Where the estate came from helps show whether it holds only past work or is part of an ongoing scientific program. For university spinouts, partners should check which institution owns the patents, the inventor assignments, and what rights the company has in every relevant family. Foundational patents may arise from federally funded research, bringing Bayh-Dole march-in rights or obligations that affect exclusivity. A university name cannot resolve those questions. Clean assignment chains and clearly defined rights must do that work.

Deep citation records suggest that founders have helped shape the field’s mechanistic understanding, while new publications, patent filings, and preclinical data show whether that work continues. Citations are a proxy. If a team has had no peer-reviewed output in five-plus years, partners should check its work against changes in the delivery literature.

Unnatural Products and Novartis structured their collaboration around UNP’s macrocyclic peptide platform IP, with substantial upfront and pre-IND milestone commitments, a multi-billion-dollar potential total, and tiered royalties. For a university-derived platform, the comparable diligence question is whether the team and rights structure can sustain future invention.

The regulatory gap that every IP-strong partnership still has to solve

No intranasal peptide product has received FDA approval on the basis of nose-to-brain delivery. This is the question the patent estate cannot answer. Standard pharmacokinetic studies measure blood concentrations, but the platform is meant to deliver drugs by a route that bypasses systemic circulation. Demonstrating human brain delivery therefore raises the need for approaches such as PET imaging or cerebrospinal fluid sampling, neither of which provides a standard submission pathway for these platforms.

Approved nasal formulations for migraines and epilepsy offer only limited comparables. They are small molecules. Partners should ask for a pre-IND meeting record or regulatory correspondence addressing how brain delivery will be demonstrated. An otherwise strong estate without that strategy has a substantial translational gap.

The FDA evaluates intranasal drug-device combinations under a combination product framework, so co-developed device protection needs a corresponding regulatory strategy. This changes how much development uncertainty the partnership must absorb and which milestones should precede a broader commitment.

How to weight these checklist dimensions against each other when making a partnership decision

Estate architecture and claim defensibility should form the foundation. If the families do not provide coherent, enforceable protection, attractive science or a more advanced pipeline cannot repair that missing position. Scientific validity then amplifies defensible claims by showing that they protect a working mechanism. Extensibility adds option value where claim scope and scientific evidence support expansion beyond the lead peptide.

Manufacturing readiness and team provenance modify that assessment. Gaps can call for milestone-gating, co-development obligations, and publication covenants, while an unscalable manufacturing process can prevent translation altogether. Regulatory uncertainty requires its own gate. Without a strategy for demonstrating human brain delivery, a research collaboration with regulatory milestone triggers is more appropriate than a full licensing deal.

AstraZeneca’s arrangement with CSPC spans eight programmes, including one clinical-ready asset, under two platforms. For peptide therapeutics, the central opportunity remains a drug class whose clinical promise is constrained by delivery. A partner who evaluates the estate correctly is acquiring a structural position in solving that constraint.