Inhalant properties

MT Vidgren, PA Vidgren, TP Paronen. Comparison of physical and inhalation properties of spray-dried and mechanically micronized disodium cromoglycate. Int J Pharm 35 139-144, 1987. 

Kawashima Y, Serigano T, Hino T, Yamamoto H, Takeuchi H. Effect of surface morphology of carrier lactose on dry powder inhalation property of pranlukast hydrate. Int J Pharma 1998 172 179-188. 

Iida, K., Leuenberger, H., Fueg, L. M., Muller-Walz, R., Okamoto, H., and Danjo, K. (2000), Effect of mixing of fine carrier particles on dry powder inhalation property of salbutamol sulfate (SS), Yakugaku Zasshi, 120,113-119. 

Vidgren M, Vidgren P, Paronen T. Comparison of physical and inhalation properties... 

The two main determinants for medicine deposition in the respiratory tract are the aerodynamic size distribution of the aerosol and the manoeuvre with which the aerosol is inhaled. They govern the mechanisms that are respraisible for particle deposition in the lungs. By varying the inhalation manoeuvre, not only the distribution in the airways for the same aerosol is changed in many cases also the amount and properties of the delivered fine particle dose are affected. The complex interplay between inhalation manoeuvre, aerosol properties and site of deposition has led to many misconceptions regarding the best inhaler choice for individual patients and the way these inhalers need to be operated to achieve optimal therapy for the patient. In this chapter the medicine deposition mechanisms for inhaled aerosols are explained as functions of the variables involved. In addition, the working principles of different inhaler types are described and it is discussed how their performance depends on many inhalation variables. Finally, some persistent misconceptions in the literature about the most preferable dry powder inhaler properties and performance are umaveUed. 

Resistance to airflow is an inhaler property that is a direct consequence of its basic design, but can be fine-tuned with the mouthpiece. Persistent misconceptions exist about the inhaler resistance and hamper an optimal inhaler choice for individual patients and the correct use of DPls. It is often postulated that operating a high resistance inhaler requires a greater effort and a higher amount of work than using a low resistance device... 

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