Soft Mist Inhalers, from which age can they be used and what are the limitations?
Wachtel1, B. Jensen1, W. Kamin2
1Boehringer Ingelheim Pharma GmbH & Co. KG, Binger Str. 173, Ingelheim, 55218, Germany
2Children’s Hospital, Evangelisches Krankenhaus Hamm, Werler Str. 130, Hamm, 59063, Germany
The paediatric development of Respimat® Soft Mist™ inhalers (SMI) is reviewed. From a regulatory point of view these are non pressurized metered dose inhalers. They have in common that their aerosols exit at low velocity and that they have initially been designed for use by adults. The effect of the age of young users was investigated in vitro and by two handling studies as well as in conventional clinical trials. Study 1 (Bickmann et al.) [[i]] dealt with the question below which age a combination of Respimat® and valved holding chamber (VHC) is required, and which degree of assistance by care givers may be appropriate. Study 2 (Kamin et al.) [[ii]] investigated the handling by children from 4 to 12 years. The judgement by study personnel was supplemented by the capture of air flow profiles which permitted objective evaluation of the success of the inhalation manoeuvre and served as a basis for in vitro evaluations of aerosol devices for young children. Results: Inhalation flow profiles should be acquired during training and administration of medication in order to predict and optimize drug deposition. In the first years of life, inhalation parameters (e.g. volume, flow rate) increase rapidly. For that reason, age, airway dimensions, and estimated lung dose are correlated when using a suitable combination of inhaler and VHC. A suitable VHC with face mask is recommended below the age of 5. Without VHC, Respimat® may be used by children at the age of 5 and above.
[i] Bickmann D, Kamin W, Sharma A, Wachtel H, Moroni-Zentgraf P, and Zielen S: In Vitro Determination of Respimat Dose Delivery in Children: An Evaluation Based on Inhalation Flow Profilesand Mouth–Throat Models, JAM 2016; 29(1): pp76–85.
[ii] Kamin W, Krackhardt D, Gössl R, Kattenbeck S, Koker P, Moroni-Zentgraf P, Wachtel H: A Handling Study to Assess the Use of the Respimat Soft Mist Inhaler in Children Aged 4–12, Pulm Ther 2015; 7: pp.