Continuous or Traditional? Building an Efficient ODF Production Workflow

Oral dissolvable films (ODFs) are no longer “simple strips.” Modern formulations carry multiple APIs, probiotics and sensitive excipients that must survive coating, drying and packaging while still delivering precise dose and fast disintegration.

Yet many manufacturers still run ODFs on traditional, stand-alone equipment trains: a coating machine from one vendor, a separate dryer, a cutting unit, and packaging sourced independently. Formulation development is disconnected from equipment design, scale-up is driven by experience rather than data, and each unit operation is validated in isolation.

As complexity grows, this model exposes higher risks in yield, scale-up and validation cost. Integrated, continuous production lines are becoming the preferred option for pharma companies and CDMOs who want robust, audit-ready ODF manufacturing. An overview of HUANGHAI’s pharma-grade approach can be found in our Pharma-Grade ODF Manufacturing solutions .

Where Traditional ODF Manufacturing Struggles

In a conventional ODF setup, the process often looks like this: R&D develops a formulation on lab tools, then production buys a coating line and dryer, and tries to “make the lab recipe fit” on commercial equipment. Typical pain points include:

• No integrated formulation support – Many equipment suppliers only sell hardware. They do not actively support formulation or stability development for multi-API or probiotic films. The customer is left to trial-and-error, and scale-up carries significant risk.
• Segmented scale-up and parameter mismatch – Lab or pilot coaters and full-size lines behave very differently. Multi-zone drying ovens often use complex temperature profiles that are hard to reproduce at larger scale, leading to delamination, wrinkles or non-uniform residual solvent.
• Heavy validation and compliance burden – Without a well-matched process concept from lab to plant, teams must repeat adjustments, rework protocols and run additional batches to prove robustness. Time-to-market and regulatory filing timelines stretch out.

HUANGHAI’s Integrated Continuous Model

HUANGHAI takes a different approach: treat the ODF line as a single, integrated process rather than a set of disconnected machines. The model combines joint formulation work, parameter matching, thermal-gradient drying and end-to-end validation support. It is part of HUANGHAI’s broader next generation of ODF solutions for complex, multi-ingredient films.

1. Co-developing a Stable ODF Formulation

Instead of handing over a finished formula and hoping it runs on the line, HUANGHAI’s process engineers work with the customer to:

• Define film structure, target thickness and dose per area.
• Optimize polymer and plasticizer systems for coating and drying behaviour.
• Evaluate solvent systems and solid content for slot-die or knife-over-roll coating.

This collaborative phase ensures that film formation and drug release characteristics are compatible with continuous coating and drying, not just small-scale casting. For projects requiring multiple APIs or functional layers, HUANGHAI’s patented Multi-Formula ODF Coating Solution provides additional flexibility in layer design and dosing.

2. Matching Parameters from Pilot to Industrial Lines

HUANGHAI uses pilot equipment that mirrors the mechanics of the industrial line (coating method, web handling, drying concept). Key process windows are established on the pilot machine—line speed, wet coating thickness, inlet air temperature and exhaust conditions—then translated to the production line with clear scaling rules.

The result is a much smoother step from lab to commercial scale: fewer unexpected film defects, shorter optimization campaigns and more predictable batch performance. This pilot-to-plant consistency is a core element in our pharma-grade ODF manufacturing configurations .

3. Thermal-Gradient Continuous Drying

Rather than relying on many independently controlled temperature zones, HUANGHAI’s ODF lines use a continuous hot-air tunnel with a natural thermal gradient. The design focuses on:

• Stable air flow and residence time across the entire web.
• Controlled, gentle solvent removal to protect heat-sensitive APIs and probiotics.
• Simplified recipe management, avoiding complex multi-zone programming.

Because the gradient is engineered into the tunnel design, the same drying behaviour can be reproduced across scales. This makes scale-up easier to justify in validation reports and more robust in day-to-day operation.

4. End-to-End Validation and Documentation

Continuous, integrated equipment alone is not enough; regulators expect clear evidence that the full process is understood and controlled. HUANGHAI supports customers with:

• Process descriptions and flow diagrams from liquid preparation to final sealed packs.
• Recommended ranges for critical parameters (e.g. coating weight, line speed, drying conditions).
• Equipment qualification and documentation packages that support IQ/OQ/PQ.

This “from solution to sachet” view helps plants navigate audits and regulatory questions with a coherent story, rather than a stack of unrelated machine manuals. For customers planning new projects, the same philosophy is reflected in HUANGHAI’s Next Generation of ODF Solutions .

Case Example: Two Heat-Sensitive APIs, One High-Yield Line

In one project, a customer needed to manufacture an ODF containing two heat-sensitive APIs. On a traditional segmented dryer, aggressive multi-zone settings led to:

• Layer separation between the active film and backing.
• Wrinkling and local over-drying.
• High scrap rates and unstable residual solvent levels.

Working together, HUANGHAI and the customer:

• Adjusted the solvent system and solid content to support smoother film formation.
• Transferred the process onto a continuous thermal-gradient dryer.
• Optimized line speed and exhaust to protect the APIs while achieving complete drying.

On the industrial line, the customer achieved over 95% good-film yield with consistent thickness and appearance. More importantly, the team could link each parameter choice back to the pilot development work, simplifying process justification in validation documents.

Why Continuous ODF Lines Do Not Require Built-in PAT

“Continuous” does not automatically mean “full of integrated PAT sensors.” For most ODF products, content and weight testing are still performed by laboratory sampling or dedicated offline instruments. The key requirement on the coating line is stable coating weight and drying behaviour.

In HUANGHAI’s view:

• Well-designed coating and drying controls deliver film thickness and residual solvent within the target window.
• Inline thickness or NIR assay sensors can be added if a specific project requires them, but they are not mandatory for a robust process.
• Keeping the core machine design simpler reduces capex, maintenance complexity and validation effort.

This allows customers to adopt QC strategies that match their regulatory environment—using lab-based assays, near-line testing or selected inline tools—without being forced into a particular PAT stack.

Conclusion: An Integrated “High-End Alternative” for ODF Manufacturing

Traditional, segmented ODF production lines can work for simple films, but they struggle when formulations become more complex and regulatory expectations tighten. Low yield, difficult scale-up and time-consuming validation are common symptoms of a disconnected process.

HUANGHAI’s integrated continuous model combines formulation support, matched pilot-to-plant parameters, thermal-gradient drying and end-to-end validation documentation into a single, coherent solution. It is designed as a “high-end alternative” to conventional equipment — delivering the performance and compliance support of premium lines with a more efficient, focused feature set.

If you are evaluating your next ODF project or planning to upgrade an existing line, you can explore:

• Pharma-Grade ODF Manufacturing
• Multi-Formula ODF Coating Solution (patented)
• Next Generation of ODF Solutions

Contact HUANGHAI to discuss a complete ODF manufacturing solution tailored to your plant.