Spinhaler device

Dmgs administered by inhalation are mostly intended to have a direct effect on the lungs. However, the efficiency of inhalation therapy is often not high because of the difficulty in targeting particles to the sites of maximal absorption. Only about 8% of the inhaled dose of sodium cromoglicate administered from a Spinhaler device (see section 9.9.2) reaches the alveoli. ... 

Spinhaler uses two perforating pins to puncture the capsule body for opening. To feed the capsule, the patient has to unscrew the device body and push the capsule into a cup that is connected with a vertical spindle holding a propeller. After closing, the capsule is pierced by sliding the outer sleeve down and back again. When the patient tilts his or her... 

Early dry powder inhaler devices were all unit-dose systems and depended on loading and triggering procedures. The Spinhaler and Rotahaler are two early examples of DPI technology. Both utilize premetered doses packed into hard gelatin capsules although different mechanisms of powder delivery are employed ... 

The Spinhaler contains pins for perforating the capsule, the cap of which fits into an impeller which rotates as the patient inhales through the device. Particles are thus dispersed into the airstream. 

Dry powder inhalers. The drug is formulated as a micronised powder and placed in a device, e.g. a spinhaler or diskhaler, from which it is inhaled. Patients can often use these when they fail with metered dose aerosols. Inhalation of powder occasionally causes transient bronchoconstriction. 

Fisons introduced the first DPI with the capsule-based Spinhaler . This was followed by a number of other capsule devices and then by unit dose blisters and multidose systems. DPIs are very diverse in their design and operation, since each product manufacturer has developed their own proprietary devices for their own drugs. 

Figure 10.5 Device categories (clockwise from left) single-capsule, Spinhaler (Aventis), multi-dose reservoir, Pulmicort (AstraZeneca), multi-dose reservoir, Asmasal Clickhaler (Medeva), and multi-dose pre-metered, Flixotide Accuhaler (GlaxoWellcome).

Typical Class I devices include powder delivery systems to the lungs such as the Spinhaler, Rotahaler, Diskhaler, spacers which are used in conjunction with a drug and are part of a drug submission. Typical Class Ha devices include power operated nebuliser systems which are usually sold separate to the drug. 

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