Inhalers & Pump sprays

Springs and stamped components designed to improve inhalers, valves, and pump sprays for optimal respiratory care

Inhalers
Feature

Valve, return, and drive springs for MDI, DPI, and soft mist platforms (SMI), plus pump spray systems, engineered for consistent force and repeatable actuation

Feature

Stamped and multislide parts for actuators, dose counters, and metering mechanisms, made to burr-free tolerances

Feature

Cleaned and packaged in ISO 7 clean rooms, manufactured to ISO 13485, with bioburden testing and full traceability

Spring for inhaler
INHALERS & PUMP SPRAYS

Relief for respiratory conditions

Inhalers and pump sprays deliver medication directly to the lungs and airways, giving fast relief in asthma and COPD. They come in several forms—metered-dose inhalers (MDI), dry powder inhalers (DPI), and soft mist inhalers (SMI)—and each one places different demands on the metal parts inside. What they share is a hard requirement: the mechanism has to release the same dose, with the same force, on the first actuation and the two hundredth. We design and manufacture the springs, stamped components, and assemblies that make that repeatability possible.


DPI Springs
INHALERS

One mechanism, three platforms

Metered-dose inhalers (MDI) rely on a spring-loaded metering valve. The spring holds the valve stem closed, then reseals it after actuation, setting both the force the patient feels and the seal that protects the next dose. It also has to live in a propellant environment without corroding or losing load.

Dry powder inhalers (DPI) have no propellant. Springs, like constant force and power springs, and stamped parts do the mechanical work of piercing, indexing, and metering the powder, and the patient's own breath carries it, so consistent mechanism travel drives dose reliability.

Soft mist inhalers (SMI) are propellant-free but mechanically energized: a spring stores the energy that drives liquid through a fine nozzle to form the mist. That places high, tightly controlled loads on the spring and on every part restraining it.

Pump sprays add their own valve and return springs, where feel and reseal define the user experience. We engineer across all four.

Springs for Inhalers
CLEANLINESS

Materials, cleanliness, and traceability

These parts sit in, or beside the drug pathway, so cleanliness is not negotiable; a loose particle can alter a dose or reach the airway. We clean and package in ISO 7 clean rooms across our global sites and manufacture to ISO 13485, with machine-vision inspection, load testing for spring rate and travel, dimensional control on stamped parts, and full material certification and traceability on every batch. Where the application calls for it, we support bioburden testing so the microbial load on delivered components is documented and controlled, not assumed.


PRODUCTS

Together, we make the perfect solution for your inhalers and pump sprays

The earlier we join your program, the more we can optimize actuation force, counter reliability, and contact design against your device architecture and formulation. We co-engineer with pharmaceutical companies, CDMOs, and device manufacturers, designing springs, stamped and multislide parts, and contacts as one system rather than three separate supply chains. From rapid prototyping through global serial production, we also deliver complete assemblies combining metal and plastic parts, so you integrate one validated subassembly and move faster from design to launch.

Products
Compression springs
Wave springs
Constant force and power springs
Assemblies & power packs
Torsion springs
Tension springs
Stamping & bending
Contact springs

Frequently Asked Questions

Can you co-engineer a new inhaler or pump spray mechanism?
Yes. The earlier RPK Medical joins, the more it can optimize actuation force, counter reliability, and contact design against your device architecture and formulation. We co-engineer with pharmaceutical companies, CDMOs, and device manufacturers, designing springs, stamped and multislide parts, and contacts as one system, prototyping rapidly, and validating through load testing and simulation before scale-up to global serial production. We also supply complete assemblies that combine metal and plastic parts, so you integrate one validated subassembly rather than managing several component suppliers.
What role does the spring play in a metered-dose inhaler?
Three families work together. Springs store and release the energy: a compression drive spring for the dose, a shielding spring for the needle guard, and constant-force springs for steady delivery of thicker drugs. Stamped and formed parts make up the structure that spring energy acts on: plunger rods, spring seats, retainers, triggers, latches, and the frames that hold everything in alignment. Contact parts handle the electrical side in connected devices. RPK Medical supplies all three as a single validated package, which removes tolerance stack-ups between suppliers.
How do spring and metal part requirements differ between MDI, DPI, and soft mist inhalers?
MDIs use a propellant, so the springs work inside or against a pressurized metering valve and must resist the propellant environment without corroding or losing load. DPIs have no propellant: springs and stamped parts do the mechanical work of piercing, indexing, or metering the powder dose, and the patient's own inhalation carries it, so consistent mechanism travel matters more than actuation pressure. Soft mist inhalers are propellant-free but mechanically energized, with a spring storing the energy that forces liquid through a fine nozzle to generate the mist, placing high and precisely controlled loads on both the spring and the parts restraining it. RPK Medical engineers for all three platforms, plus the return and valve springs used in pump sprays.
Which stamped and multislide metal parts go into inhalers and pump sprays?
Much of the mechanism is stamped and formed metal: dose-counter ratchets, pawls, and index wheels, canister retainers, valve components, actuator clips, piercing elements in DPIs, and the frames that keep everything aligned. Progressive-die stamping is the most cost-effective route for high-volume, simpler geometries. Multislide (fourslide) forming shapes slit coil or wire from several directions at once, which suits the intricate multi-bend clips, pawls, and formed springs that inhaler mechanisms depend on, with less scrap and no carrier rails. Multislide also feeds material along its grain direction, improving fatigue resistance in parts actuated hundreds of times over a device's life.
How do you make dose counters count accurately?
Dose counters are a regulatory expectation on modern inhalers, and they fail in two directions: undercounting leaves a patient using an empty device during an attack, while overcounting wastes doses. The mechanism is usually a spring-loaded ratchet and pawl that indexes exactly one step per actuation. Accuracy comes from tight, repeatable tooth geometry on the stamped parts and a spring that returns the pawl with the same force every time. RPK Medical holds those tolerances with machine-vision inspection and controls burr formation on tooth edges, since a burr is enough to cause a skipped or double count.
What are contact parts used for in connected inhalers?
Smart inhalers add electronics that record when and how a dose was taken and sync it to an app, supporting adherence monitoring in asthma and COPD. That requires contact (contactor) parts such as battery contacts, actuation switches, and sensor contacts that register each dose, which must make reliable, repeatable electrical contact through the full life of the device. RPK Medical forms them to tight tolerances with controlled contact force and clean, burr-free edges, and selects or plates materials for stable conductivity and corrosion resistance. EMI/ESD-safe stamped parts keep static and interference from disturbing the electronics, and because the same lines form contact parts and structural parts, the mechanical and electrical components arrive matched.
Which materials do you use for inhaler springs, and how small can the parts be?
Material choice is driven by the environment inside the device: propellant exposure in MDIs, moisture sensitivity in DPIs, and long dormant periods in rescue inhalers where a spring must not take a set. RPK Medical works in 316 and other stainless steels, Hastelloy, and Elgiloy, selecting for corrosion resistance, fatigue life, and stable elastic behavior. Wire and strip start from 0.10 mm, which makes the compact valve and counter mechanisms in a handheld inhaler possible.
What cleanliness and quality standards apply to inhaler components?
Inhaler and pump spray parts sit in the drug pathway or immediately next to it, so particulate control is critical, since a loose particle can affect the delivered dose or reach the patient's airway. RPK Medical cleans and packages in ISO 7 clean rooms across its global sites and manufactures to ISO 13485, with machine-vision inspection, load testing against specified spring rate and travel, dimensional control on stamped parts, and full material certification and traceability. MDI and DPI products are regulated as combination products, so this component-level evidence feeds directly into customers' regulatory submissions.

Do you need help with your next project?

Get in touch with our engineering and sales teams. We will help you to find the best solution for your application.

Contact us now