Selecting a drug delivery partner is one of the highest-stakes decisions in early-stage pharmaceutical development. The wrong choice doesn’t show up immediately – it surfaces six to eighteen months later, when a reformulation is needed, when scale-up fails to reproduce lab results, or when a regulatory submission reveals gaps in analytical documentation that the partner wasn’t equipped to fill. By that point, the cost is measured not just in budget but in program timeline. Choosing the right drug delivery companies from the start can help avoid these costly setbacks and ensure smoother development.
This guide is for R&D leaders and business development teams evaluating drug delivery companies for lipid-based formulation programs – particularly those involving LNP technology, liposomal encapsulation, RNA-based therapeutics, or other advanced delivery systems where the complexity of the formulation science is high and the margin for error is narrow.
Why formulation expertise is the starting point, not the endpoint
The core service any drug delivery company offers is formulation development – designing a delivery system that gets your therapeutic molecule to its target in sufficient concentration, with acceptable stability, and without compromising safety. For lipid-based systems, this is considerably more complex than it sounds.
Lipid nanoparticles (LNPs) and liposomes are not static structures. Their physicochemical properties – particle size, polydispersity index, surface charge (zeta potential), encapsulation efficiency, and lipid composition – interact in ways that affect biodistribution, cellular uptake, endosomal escape, and ultimately efficacy. Small changes in lipid ratio, pH of the aqueous phase, or mixing conditions during formulation can produce meaningful differences in in vivo performance.
A drug delivery company with genuine formulation depth will approach this through Quality by Design (QbD) methodology and ICH guidelines – systematically mapping the design space of critical process parameters and their effect on critical quality attributes. This is not merely a regulatory nicety. It is the difference between a formulation that is understood and reproducible, and one that works until it doesn’t.
When evaluating a potential partner, ask specifically how they apply QbD to formulation development. Ask to see examples of Design of Experiment (DoE) outputs. Ask how they define and track critical quality attributes across development stages. The answers will quickly reveal whether formulation science is genuinely embedded in their process or whether it is retrofitted for regulatory documentation.
The lipid-based delivery landscape: matching the system to the molecule
Not all drug delivery companies work with all delivery systems. The lipid-based space encompasses several distinct technologies, each suited to different therapeutic payloads and administration routes:
Liposomes – spherical vesicles with a lipid bilayer capable of encapsulating both hydrophilic (aqueous core) and hydrophobic (membrane) drugs. Well-established regulatory precedent, multiple approved products. Suited for small molecules, peptides, and certain nucleic acid applications.
Lipid nanoparticles (LNPs) – the delivery system behind approved mRNA COVID-19 vaccines and a growing pipeline of RNA therapeutics. LNPs are specifically engineered for nucleic acid delivery, incorporating ionisable lipids that facilitate endosomal escape. The formulation science is significantly more demanding than classical liposomes and requires specific process equipment and analytical capability.
Solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) – solid-matrix systems offering improved stability over emulsions, suited for hydrophobic small molecules with sustained release requirements.
Nanoemulsions and SEDDS (self-emulsifying drug delivery systems) – primarily for improving bioavailability of poorly water-soluble small molecules via oral or parenteral routes.
A company with broad expertise across these systems can advise on the most appropriate technology for your molecule early in the program, before significant resources are committed to a suboptimal formulation strategy. A company that works only in one system will frame every problem as a nail for their particular hammer.
The question to ask: which delivery systems do you have active development projects in, and which do you have regulatory submissions or approved products for? Track record in regulatory submissions is a stronger signal than capability claims.
Analytical capability: the infrastructure of formulation development
Drug delivery development without robust analytical infrastructure is guesswork. The formulation needs to be characterised at each development stage, the characterisation needs to be reproducible, and the methods need to be appropriate for eventual regulatory submission.
For lipid-based systems, the core analytical toolkit includes:
- Dynamic light scattering (DLS) and nanoparticle tracking analysis (NTA) for particle size and polydispersity
- Zeta potential measurement for surface charge characterisation
- Encapsulation efficiency assays (Ribogreen for nucleic acids, HPLC for small molecules)
- Transmission electron microscopy (TEM) or cryo-TEM for morphological characterisation
- Stability testing under ICH conditions (accelerated and long-term)
- In vitro release and potency assays appropriate to the therapeutic modality
If the partner is supporting RNA-based therapeutics specifically, additional considerations include RNA integrity analysis (gel electrophoresis, capillary electrophoresis), dsRNA impurity profiling, and bioassays for mRNA translation activity.
Ask to see their analytical method list and ask which methods are validated versus qualified. For a late-stage partner, method validation status matters directly for regulatory submissions. For an early-stage partner, the ability to develop and transfer analytical methods is what matters.
Scale-up path: from discovery to clinical manufacturing
One of the most underappreciated risks in outsourced drug delivery development is scale-up discontinuity – where a formulation developed at laboratory scale fails to reproduce at larger batch sizes, requiring reformulation and timeline loss.
The root causes are usually process-related: mixing dynamics change at scale, shear forces in microfluidic or extrusion equipment differ between benchtop and pilot instruments, and thermal management during processing becomes more complex. A partner whose laboratory and pilot-scale equipment are from the same technology platform, and who has actively demonstrated scale-up on multiple projects, reduces this risk substantially.
What to evaluate:
- What is the smallest batch size they can run, and what is the largest? A partner who can work from sub-milligram to pilot scale allows the formulation to be explored at early stage without wasting expensive material, then moved through development without a technology transfer gap.
- Have they demonstrated scale-up on lipid nanoparticle systems specifically? LNP scale-up is not identical to liposome scale-up; the manufacturing parameters interact differently.
- What is the process transfer documentation like? Can they provide examples of development reports that document formulation parameters at each scale?
For programs heading toward clinical supply, the scale-up path must ultimately connect to cGMP manufacturing. A partner who can take a formulation from discovery through cGMP production under one roof eliminates the technology transfer risk that comes with changing manufacturing organisations between development stages.
cGMP capability and regulatory readiness
For any program intending to generate clinical supply, cGMP manufacturing capability is not optional. It is the regulatory foundation on which safety and efficacy data are built.
cGMP compliance in the context of lipid-based injectables (which includes most LNP formulations) requires:
- Sterile manufacturing environment with appropriate cleanroom classification
- Validated equipment with documented installation and operational qualification (IQ/OQ)
- In-process and final product testing against pre-defined specifications
- Batch record documentation sufficient for regulatory inspection
- Stability programme and environmental monitoring
Ask any prospective partner for their most recent regulatory inspection outcome. Ask whether their facility has been inspected by FDA, EMA, or equivalent agencies, and what the outcome was. Ask specifically whether their cGMP zone covers the formulation, filling, and finishing steps you need, or whether they outsource any of these to third parties.
Outsourcing fill and finish to a third party is common and not inherently problematic, but it introduces an additional technology transfer, an additional quality agreement, and an additional potential failure point. Partners who can perform aseptic fill and finish in-house – including formats like vials, pre-filled syringes, and cartridges – offer a more streamlined path from formulation development to clinical batch release.
The integrated CDMO model: why end-to-end matters for RNA therapeutics
For programs involving RNA-based therapeutics – mRNA, siRNA, saRNA, antisense oligonucleotides – the relationship between the nucleic acid molecule and its delivery system is unusually tight. The RNA must be of sufficient quality and integrity before encapsulation; the LNP formulation must be optimised for the specific RNA construct; the analytical release testing must cover both the RNA payload and the lipid vehicle.
If RNA synthesis is done by one organisation and LNP formulation by another, the interface between the two becomes a coordination and quality risk. Questions about which organisation is responsible for encapsulation efficiency variability, or how to attribute a potency shortfall to the RNA versus the LNP, become difficult and slow to resolve.
An integrated CDMO that covers RNA synthesis, formulation development, analytical characterisation, and scale-up to cGMP manufacturing under one roof eliminates this interface risk. It also simplifies regulatory documentation, since the chain of custody for the therapeutic molecule is continuous and the responsible organisation is single.
SyVento BioTech operates as exactly this kind of end-to-end partner – offering RNA synthesis, lipid-based formulation development (liposomes, LNPs, SLN, NLC, nanoemulsions, SEDDS), analytical services, scale-up from lab to 50L batches, and aseptic fill and finish for vials, pre-filled syringes, and cartridges. The R&D team is entirely PhD-level in life sciences, the facility includes both GLP and cGMP zones near Kraków, and formulation development follows QbD and ICH guidelines throughout.
Red flags to watch for in the evaluation process
A few patterns that should raise questions during partner evaluation:
Overpromising on timelines without seeing your molecule. Formulation development timelines depend heavily on the physicochemical properties of the payload, the desired delivery route, and the regulatory pathway. A partner who quotes a timeline before reviewing your data is not planning – they are selling.
No clear scale-up data. If a partner cannot show you development reports documenting formulation parameters at multiple scales, their scale-up capability is theoretical, not demonstrated.
cGMP certification without active regulatory inspections. Self-certified GMP is not the same as a facility that has been inspected and cleared by a regulatory authority. Ask for documentation.
Inability to provide QbD-aligned development reports. If the partner’s development documentation is not structured around critical quality attributes and critical process parameters, the data will not support a regulatory submission without significant rework.
Single-system expertise in a multi-system landscape. A partner who has deep expertise in liposomes but no active LNP programs is not the right partner for an mRNA therapeutic, regardless of what their capabilities brochure says.
When to engage a drug delivery partner in your development program
The earlier, the better – with one important qualification. Engaging a formulation partner at the stage when your molecule is well characterised but the delivery strategy is not yet fixed gives you the most value. They can advise on delivery system selection, help you avoid early-stage decisions that create downstream problems, and build institutional knowledge of your program that will accelerate later stages.
Engaging a partner after the formulation strategy is locked and the development is already underway is still valuable for scale-up and manufacturing, but you lose the benefit of their formulation expertise at the decision point where it matters most.
For programs where the delivery system is central to the mechanism of action – which is true of essentially all RNA-based therapeutics and targeted nanoparticle systems – the formulation partner should be at the table when the development strategy is being written, not brought in to execute a strategy designed without them.
Summary: the evaluation criteria that matter
The list of criteria that differentiate strong drug delivery partners from adequate ones is shorter than it might appear. The core questions are:
- Do they have demonstrated, documented expertise in the specific delivery system your program requires – not just claimed capability?
- Is their formulation development process built on QbD and ICH methodology throughout, or only at the end for regulatory packaging?
- Can they cover the full development arc from discovery-scale formulation to cGMP manufacturing, without requiring a technology transfer to a different organisation?
- Is their analytical capability sufficient for your regulatory pathway, and are their methods validated or validatable?
- Do they have active regulatory inspection history, and what does it show?
A partner who can answer all five questions with evidence rather than assertions is a partner worth investing time in evaluating further.
