Hydrodynamic flow focusing (HFF) production of lipid nanoparticles engineered for reproducible size control, efficient payload encapsulation, and scalable process development.
Hydrodynamic flow focusing has become a preferred microfluidic strategy for preparing lipid nanoparticles (LNPs) when formulation teams need tighter control over self-assembly than is typically achievable with conventional bulk mixing. By confining an organic lipid stream between aqueous sheath flows, HFF enables rapid and tunable solvent exchange, supporting the formation of LNPs with defined particle size, narrow size distribution, and robust encapsulation behavior. For drug developers working with mRNA, siRNA, pDNA, peptides, or small molecules, this approach is particularly valuable when process consistency, formulation screening, and scale-up translation must be considered from the beginning. BOC Sciences provides specialized hydrodynamic flow focusing LNP production services to help clients move from concept evaluation to optimized process windows through disciplined control of lipid composition, mixer conditions, flow rate ratio, total flow rate, and downstream characterization.
Flow focused microfluidic lipid nanoparticle productionWe design HFF-based LNP preparation workflows for research and pre-manufacturing development teams seeking precise control over particle formation, formulation robustness, and data-driven process optimization.
We establish hydrodynamic focusing conditions that promote controlled nanoprecipitation and lipid self-assembly for nucleic acid and drug-loaded LNP systems.
LNP performance depends on the interplay between the mixing regime and formulation chemistry. We tailor component ratios to the physicochemical requirements of your cargo.
We perform structured screening studies to define how key HFF variables influence particle characteristics and formulation reproducibility.
We support hydrodynamic flow focusing workflows for distinct delivery objectives across multiple therapeutic modalities.
LNP quality is influenced not only by mixer settings but also by how solvent removal and post-processing are handled immediately after formation.
We connect production studies with analytical testing so clients can make formulation decisions based on complete process-structure-property relationships.
HFF is especially valuable when formulation teams need more than simple particle generation. It provides a controlled fluidic environment for understanding how rapid solvent exchange and lipid self-assembly translate into measurable formulation performance.
From first-pass screening to parameter refinement, BOC Sciences helps you identify the hydrodynamic focusing conditions that best support your target particle profile and encapsulation goals.
We combine formulation science, microfluidic process design, and downstream analytics to help clients understand not just whether an LNP can be produced, but why a specific HFF condition performs better than another.
| Capability Area | What We Evaluate |
|---|---|
| Microfluidic Mixing Design | HFF geometry selection, inlet arrangement, focusing behavior, and operating ranges for reproducible LNP formation. |
| Formulation Composition | Ionizable lipid/helper lipid/PEG-lipid ratios, lipid concentration, aqueous phase selection, and payload compatibility. |
| Particle Size Readout | Direct coupling with nanoparticle size analysis to compare diameter and PDI across FRR/TFR conditions. |
| Surface Properties | Zeta potential and dispersion behavior assessment via nanoparticle zeta potential analysis. |
| Loading and Encapsulation | Quantification of cargo association using payload-specific methods, including optional nanoparticle drug loading analysis. |
| Stability-Oriented Screening | Evaluation of post-mixing conditioning, buffer exchange response, short-term storage behavior, and formulation robustness. |
Clients typically come to us not because they need "an LNP," but because existing formulations are unstable, irreproducible, or difficult to scale with confidence.
✔ Broad Particle Size Distribution
When bulk or insufficiently controlled mixing produces large size variability, we refine focusing conditions and solvent exchange kinetics to narrow particle distributions.
✔ Encapsulation Loss During Process Transfer
Payload retention often drops when formulation conditions are changed too aggressively. We map practical operating windows that maintain encapsulation while improving process consistency.
✔ Aggregation After Buffer Exchange
Some LNPs look acceptable immediately after HFF mixing but destabilize during pH adjustment or solvent removal. We optimize the transition sequence to preserve colloidal integrity.
✔ Poor Reproducibility Across Runs
Minor changes in flow balance, concentration, or sample handling can alter final particle attributes. We build more reproducible workflows through parameter discipline and analytical verification.
✔ Payload-Specific Formulation Sensitivity
mRNA, siRNA, pDNA, and protein cargoes do not respond identically to the same HFF condition. We adapt mixing logic and formulation composition to the actual molecular payload.
✔ Limited Scale-Up Confidence
We help clients translate bench-scale HFF findings into process knowledge that can guide scale-up decisions, device selection, and manufacturing-oriented development planning.
We assess your payload, lipid composition, target size range, intended application, and current process bottlenecks to define an appropriate HFF strategy.
Organic and aqueous phases are configured, starting FRR/TFR ranges are selected, and preliminary HFF runs are performed to establish viable particle formation conditions.
We compare candidate conditions using size, PDI, zeta potential, encapsulation, and stability-oriented data to identify the most promising operating window.
You receive a structured report summarizing tested conditions, critical observations, comparative data, and practical next-step recommendations for continued LNP development.
Challenge: A client developing an ionizable lipid-based mRNA system obtained LNPs with acceptable encapsulation but inconsistent particle size, typically ranging from 75-145 nm across repeated microfluidic runs.
Project Features: The formulation used a four-component lipid system with an acidic aqueous phase and ethanol lipid feed. The client's internal target was a mean diameter below 90 nm with a lower PDI to improve formulation consistency across screening batches.
Solution: BOC Sciences redesigned the HFF study around a focused matrix of FRR, TFR, and lipid concentration. We first held the total lipid concentration constant while screening FRR values from 2:1 to 5:1, then fixed the best-performing FRR range and evaluated higher total flow rates to determine whether narrower solvent exchange timing would improve assembly uniformity. Analytical comparison showed that the client's original condition was producing incomplete focusing stability at the selected feed concentration. By shifting to a narrower operating window and introducing a more controlled post-mixing dilution step, we identified a condition that consistently reduced oversized subpopulations.
Result: The optimized HFF condition produced LNPs centered at approximately 82-88 nm with a markedly narrower size distribution and improved run-to-run reproducibility, giving the client a more reliable formulation basis for subsequent performance studies.
Challenge: A research team preparing siRNA-loaded LNPs through hydrodynamic flow focusing observed good initial particle formation but significant aggregation after buffer transition, especially during short-term storage.
Project Features: The system contained an ionizable lipid, cholesterol, a phospholipid helper component, and PEG-lipid. Initial particle size met the target range immediately after HFF production, but the z-average shifted upward after post-processing, and the team needed a more stable workflow without sacrificing loading.
Solution: Our team investigated whether the instability originated from the mixing event itself or from downstream conditioning. We compared several HFF conditions while keeping the siRNA input constant, then evaluated different solvent reduction and pH transition sequences. The data showed that particle growth was driven less by the initial focusing event than by the speed and order of post-mixing adjustment. We therefore established a revised conditioning workflow with a gentler transition profile, combined with a modest reformulation of PEG-lipid proportion to improve colloidal stabilization.
Result: The optimized process preserved the desired particle range more effectively during storage-relevant handling and maintained high siRNA association, allowing the client to continue formulation screening with greater confidence in process robustness.
Process-Centered DevelopmentWe treat HFF-LNP production as an integrated process problem rather than a single mixing step, linking device behavior, formulation chemistry, and analytical outcome.
Payload-Specific ExpertiseOur workflows are adapted to the demands of mRNA, siRNA, pDNA, peptides, proteins, and small molecules rather than applying a one-condition-fits-all recipe.
Structured Parameter OptimizationWe systematically examine FRR, TFR, concentration, and composition so clients can identify a true operating window instead of relying on isolated trial-and-error runs.
Integrated AnalyticsProduction studies can be directly connected to size, surface charge, encapsulation, and stability testing to provide decision-ready formulation data.
Development-to-Scale PerspectiveWe help clients generate HFF process knowledge that supports later transfer into broader LNP development and manufacturing planning.
Hydrodynamic Flow Focusing (HFF) is a mixing technology achieving precise fluid control within microfluidic chips for LNP production. In LNP production, the organic phase (ethanol solution containing lipids) is introduced from the central channel while the aqueous phase (buffer containing nucleic acids) is introduced from side channels at higher flow rates. Due to viscous shear effects, the aqueous phase compresses the organic phase into a narrow laminar stream, after which both phases rapidly contact and complete lipid nanoparticle self-assembly in the chip mixing region. The core advantage of HFF technology lies in generating highly reproducible fluid interfaces and enabling precise control over particle size and encapsulation efficiency through accurate regulation of total flow rate ratio (TFR) and flow rate ratio (FRR). BOC Sciences employs advanced hydrodynamic flow focusing microfluidic platforms, providing complete LNP production services from formulation screening to scale-up for clients.
The core principle of HFF is to compress the central organic phase into a narrow stream using side aqueous flows, allowing lipid molecules to form LNPs under a controlled diffusion and self-assembly environment. As a result, total flow rate, flow rate ratio, lipid concentration, solvent composition, channel geometry, and mixing distance can all influence final particle size and distribution. For drug development customers, this means the process is not simply “mixing,” but a tunable system that can be optimized around a target particle size range. A well-designed parameter window can help reduce batch-to-batch variation and provide a clearer data foundation for further formulation optimization.
Compared with traditional batch mixing, Hydrodynamic Flow Focusing emphasizes a continuous, controllable, and reproducible microscale mixing environment, which can reduce the influence of local concentration fluctuations on LNP self-assembly. Traditional methods often depend more heavily on stirring intensity, order of addition, and operator experience, while HFF allows more precise adjustment through parameters such as flow rate ratio, channel geometry, and residence time. For formulation development teams, this difference can support more efficient screening of lipid ratios, loading conditions, and buffer systems, while reducing result variability caused by unstable mixing conditions.
Key parameters that affect HFF LNP production performance generally include lipid composition, total flow rate, flow rate ratio, RNA or drug-to-lipid ratio, buffer pH, ethanol content, temperature, chip channel structure, and post-processing conditions. Customers often ask which parameter is the most important during early development, but in real projects, interaction effects usually need to be assessed through combined experimental designs. BOC Sciences’ nanoparticle services can help customers build evaluation matrices around particle size, distribution, encapsulation performance, surface charge, and stability trends, allowing formulation screening to move from isolated trial-and-error experiments toward a more systematic development strategy.
HFF LNP production has continuous-flow characteristics and can support the transition from small-scale formulation screening to higher-throughput process studies. However, scale-up is not simply a matter of increasing flow rate; it also requires attention to chip parallelization, flow stability, clogging risk, shear environment, mixing efficiency, and process consistency. For drug development customers, an effective approach is to document the relationship between key parameters and LNP attributes from the early stage. This creates a traceable process understanding, making it easier to determine which conditions can be maintained and which ones may need further optimization when preparation volume increases.
