Micro Systems Highlights Precision Moulding for Pulmonary Drug Delivery at DDL 2025

Micro Systems specialises in high-precision mould and tooling, micro injection moulding and design-for-manufacture partnerships for drug delivery to the lungs devices. Micro Systems will be exhibiting at the Drug Delivery to the Lungs (DDL) 2025 conference and would welcome the opportunity to discuss how precision moulding can de-risk your inhalation-device programme and speed time to market. Come and meet the technical team at DDL on 10th – 12th December 2025 at Stand 112, Edinburgh International Conference Centre, to review tooling strategies, material selection and scale-up pathway.

Pulmonary drug delivery is uniquely sensitive to device geometry and component quality: small changes in nozzle shape, mouthpiece contour or internal channelling can change aerosol velocity, particle size distribution and ultimately where drug deposits in the lung [1].

Precision in moulded parts therefore influences not only manufacturability and cost, but also in-vitro performance and clinical predictability. Modern injection moulding techniques, tooling and materials engineering need to meet the tight tolerances and surface requirements of inhalation devices, with actionable points for device designers and pharmaceutical partners.

The manufacturing challenges for inhalation devices

Inhalation devices combine micro-scale fluid dynamics with human factors and regulatory constraints. Typical manufacturing challenges include:

• Micrometric dimensional control: Features such as orifice diameter, stem fit and air-inlet geometry are critical to spray pattern or powder de-agglomeration; deviations of a few tenths of a millimetre can materially affect performance [2].
• Repeatable surface finish: Surface roughness alters interfacial behaviour (powder adhesion in DPIs, droplet formation in MDIs or soft-mist devices) and must be controlled across production lots [3].
• Material compatibility and low extractables: Materials must resist propellants and formulation components, retain dimensional stability under humidity and meet biocompatibility or extractables expectations [4].
• Process traceability and quality systems: Demonstrating control of critical-to-quality (CTQ) attributes, process capability (Cp/Cpk) and traceability is essential for regulatory submissions and product launch [5].

How advanced injection moulding answers these needs

Recent developments in tooling, process control and micro-moulding techniques allow manufacturers to consistently reproduce micro-features and surface finishes required for inhalation components.

1. Tooling and micro-feature replication

High-precision mould steels, micro-EDM, ultra-fine CNC machining and electrical-discharge finishing allow replication of nozzles, stems and complex mouthpiece channels to very tight tolerances. Precision tool design, including hot-runner optimisation and multi-cavity balancing, reduces part-to-part variability that would otherwise translate to inconsistent aerosol output [6].

2. Micro- and thin-wall injection techniques

Micro injection moulding (µIM) and thin-wall processes control melt-front behaviour, shear history and cooling rates to preserve micro-geometry and surface integrity. Inline sensors (melt pressure, cavity pressure, temperature) and closed-loop control enable consistent filling of micro features across high-volume runs, improving first-pass yield [7].

3. Surface finishing and functionalisation

Controlled tool polishing grades, laser texturing and selective coatings (where appropriate and compatible) let manufacturers tune part surfaces to aid powder release in DPIs or control wettability for liquid-based systems. Using surface parameter metrics as part of quality indices helps align manufacturing output with aerosol performance targets [3].

4. Material selection and qualification

Engineering thermoplastics such as medical-grade polypropylenes (PP), acetal (POM) and high-performance polyesters are frequently chosen for inhaler components because of dimensional stability, low moisture uptake and suitable tribological properties. Selection must consider extractables/leachables, long-term storage stability and interaction with propellants or excipients; these considerations are embedded in regulator guidance [4].

From component precision to aerosol performance

There is a clear body of experimental work linking device geometry to aerosol metrics such as fine particle fraction (FPF), emitted dose and throat deposition. Studies demonstrate that mouthpiece geometry, internal channels and turbulence-inducing features can alter axial velocity, promote powder de-agglomeration and change the fraction of drug reaching the peripheral lung [1, 8]. Precise, repeatable manufacture of these features therefore helps device and formulation teams achieve targeted in-vitro endpoints.

Regulatory and standards context

Regulatory agencies expect a risk-based approach to the design and manufacture of inhalation products. The FDA’s guidance on MDI and DPI quality considerations outlines expectations for identifying CTQs, performing appropriate characterisation (spray pattern, plume geometry, aerodynamic particle-size distribution) and documenting control strategies [2]. Likewise, the EMA’s revised guideline on pharmaceutical quality for inhalation and nasal products emphasises modern, science-based approaches to device and component quality [9]. Complying with these frameworks requires early alignment between formulation scientists, device designers and precision moulders.

Design for Manufacture (DFM): reduce risk early

Embedding DFM and mouldability reviews at the concept stage mitigates downstream risk. Practical DFM actions include:

• defining CTQs (for example nozzle diameter ± tolerance);
• running mould-flow and warpage simulations to identify probable sinks, welds or differential shrinkage;
• early µIM prototype runs to validate functional geometry before committing to high-cost production tooling; and
• material compatibility and accelerated-ageing studies to de-risk long-term stability.

These steps shorten development cycles, reduce regulatory queries and lower scrap during scale-up [7, 10].

Scaling to volume: keeping precision under control

Maintaining micro-feature fidelity during scale-up requires controls across tooling, process and environment:

• Tool life management: micro-features are sensitive to wear; tool metallurgy, coating and maintenance schedules must manage drift.
• Process-capability monitoring: establishment of Cp/Cpk for CTQs and routine capability studies guard against process degradation.
• Cleanroom and contamination controls: for components that assemble into drug-contacting systems, appropriate cleanroom classification, handling and assembly controls are mandatory.
• Traceability: material batch records, tool-ID systems and production-lot tracking simplify investigations and regulator inspections [5].

Emerging trends to watch

The global pulmonary drug delivery systems market was valued at USD 53.24 billion in 2023 and is projected to reach USD 72.33 billion by 2030, growing at a CAGR of 4.6% from 2024 to 2030. Similarly, the global market for inhalation drug delivery devices is expected to reach

USD 24.5 billion by 2033, growing at a CAGR of 4.4% over the forecast period. These figures underscore the increasing demand for precision in the design and manufacturing of inhalation devices.

Key directions likely to influence inhaler manufacture over the next five years include:

• wider adoption of digital twins and predictive process control for cavity-level consistency [10];
• hybrid manufacturing and novel µIM tooling for ever-smaller or more complex features [6];
• increased regulatory focus on product-level performance and lifecycle control [9]; and
• a growing emphasis on sustainability and material circularity for single-use or disposable device elements.

Precision injection moulding is a measurable enabler of reliable pulmonary drug delivery. When tooling, process control, surface engineering and material qualification are aligned with device design and regulatory expectations, manufacturers can deliver components that preserve intended aerosol performance and support predictable clinical outcomes [1, 2].

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References

[1] Hinds WC. Mechanisms of Pharmaceutical Aerosol Deposition in the Respiratory Tract.
PubMed Central.
[2] U.S. Food and Drug Administration. Metered Dose Inhaler (MDI) and Dry Powder Inhaler (DPI) Drug Products – Quality Considerations. Guidance for Industry. FDA, 2018 (draft).
[3] ONdrugDelivery. High-Precision Injection Moulds for Inhalers: Challenges and Solutions. [4] Gerresheimer. Injection Moulding for Drug Delivery Systems. Technical overview of thin-wall, multi-component and micro-injection capabilities.
[5] ISO 20072:2024. Aerosol Drug-Delivery Devices – Design Verification Requirements.
International Organization for Standardization.
[6] Zhang H et al. A Review of Micro-Injection Moulding of Polymeric Micro Devices.
Materials, PMC.
[7] Ferraro S et al. Micro-Injection Moulding In-Line Quality Assurance Based on Cavity Pressure Sensing.Micromachines, PMC.
[8] Clark AR et al. Influence of Mouthpiece Geometry on the Aerosol Delivery Performance of a Dry Powder Inhaler.PubMed.
[9] European Medicines Agency. Guideline on the Pharmaceutical Quality of Inhalation and Nasal Medicinal Products (Revision 1). EMA, 2024.
[10] De Keyser J et al. Digital Twin Approaches for Quality Control in Polymer Micro-Manufacturing. Precision Engineering Journal, 2023.