New inhaler is child's play

A new inhaler with a child-friendly design aims to solve the problem of dosage variance and patient compliance - key issues with inhaled drug treatments for children.

The new Watchhaler product from Activaero uses novel design features and has been designed to appeal to kids, with vivid colours and an 'animal-like shape'.

The new product is used in combination with conventional metered dose inhalation devices (MDIs), and addresses several concerns associated with traditional spacer inhalation devices. Spacers are large chambers that are fitted to an inhaler, and the dose is then breathed in from the spacer though a mouthpiece or mask.

One major issue the developers hoped to overcome was the fact that there is high variability in the mass of the drug that is actually delivered to a patient's lungs when using inhalation devices. This is not solely down to the design of the device itself, but also individual patients' compliance with labelled instructions.

"Especially for pressurised metered dose inhalation devices it has been shown that in adults, only 25 per cent of patients were able to perform inhalation with an MDI correctly," say the company.

"In children it is even worse and lung deposition is less than 5 per cent."

In order to combat this dosage variance, Activaero, in collaboration with UK plastics manufacturer RPC Formatec, has developed a device that incorporates a silicone balloon within a transparent plastic chamber, which is used as a reservoir for the aerosolised drug.

An MDI device is used to fill the balloon through the mouthpiece, the volume of the balloon limiting the inhalation volume. A patented mechanical valve at the air inlet on the other side of the mouthpiece reduces the inhalation flow rate (limiting it to 150ml/s), allowing slow, controlled delivery of the therapeutic aerosol.

As the drug is inhaled, the silicone balloon deflates, folding up to visually illustrate that the drug has been successfully inhaled. This provides parents and supervisors with a clear means of identifying whether a child has inhaled a full dose, and is also intended to motivate the child to continue inhaling.

The silicone balloon and outer chamber design features also serve another purpose, tackling the problem of electro-static charge common with plastic spacer devices. Plastic spacers can become electro-statically charged through handling, which can greatly reduce the efficacy of drug delivery as the charge attracts the drug particles to the walls of the spacer, reducing the time available for inhalation.

The protective outer layer of the Watchhaler means that the aerosol balloon is not touched, which means the drug remains airborne for longer, increasing the time available for inhalation to over two minutes.

At a cost of around €30, the child-friendly Watchhaler is about the same price as a mid-range conventional spacer.

In 2005, over 22 million people in the US alone had asthma, 6.5 million of them children. In Europe it is estimated that around 1.6 million children under the age of five suffer from asthma. Worldwide the disease affects around 300 million people, and in 2005 over a quarter of a million people died as a direct result of asthma.

The Watchhaler product was in development for around two years while the company optimised the device, and is protected by several international patents. The inhaler will be officially launched in March at the DGP conference in Mannheim, Germany.

Activaero are also in the process of developing the second generation of one of their other products, the Akita. The new product is an inhalation device that is coupled with a drug - a liquid nebuliser system that is electronically controlled, which is particularly good news for patients using expensive drugs which have to be precisely dosed with minimal wastage. The product is in Phase I studies which are due to be completed soon, according to a company spokesperson.