Comparison between the next generation impactor and the twin glass impinge as model pulmonary drug delivery devices


  • Huner Kamal Omer Department of Pharmaceutics, College of Pharmacy, Hawler Medical University, Erbil, Iraq
  • Nozad Rashid Husein Department of Pharmaceutics, College of Pharmacy, Hawler Medical University, Erbil, Iraq
  • Hewa Abdulla Hamadameen Department of Pharmaceutics, College of Pharmacy, Hawler Medical University, Erbil, Iraq



Twin glass impinge, Next generation impactor, Dry powder inhaler


Background and objective: The British Pharmacopoeia contains four apparatus for testing inhalers. Two of these are the next generation impactor, and the twin glass impinge which differs in their use. The next generation impactor apparatus should ideally have at least five stages; even though the twin glass impinge has only two stages, it is still listed in the British Pharmacopoeia. The next generation impactor is more accurate, reliable and sophisticated than the twin glass impinger. This study gives a detailed comparison of the two pieces of equipment.

Methods: Carriers including mannitol, lactose monohydrate, trehalose and sucrose with active pharmaceutical ingredient; salbutamol sulphate were delivered by dry powder inhaler using the next generation impactor and twin glass impinger at a constant flow rate of 60L/min.

Results: The twin glass impinge respirable fractions of the powders were higher than the next generation impactor for each carrier. As expected, mannitol powder had the lowest percentage remaining in the capsule compared to lactose monohydrate, trehalose and sucrose had the greatest percentage remaining for both inhaler devices.

Conclusion: Even though both apparatus are important for in-vitro studies of drug delivery into the lungs using inhaler devices, the next generation impactor is better suited when a specific size range is required. The twin glass impinger is useful for simple inhaler testing, and the inclusion within the British Pharmacopoeia is justified.


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Hamishehkar H, Rahimpour Y, Javadzadeh Y. The Role of Carrier in Dry Powder Inhaler. In: Recent Advances in Novel Drug Carrier Systems. INTECH; 2012.

Rudolf G, Köbrich R, Stahlhofen W. Modelling and algebraic formulation of regional aerosol deposition in man. J Aerosol Sci 1990; 21:S403–6.

Hallworth GW, Westmoreland DG. The twin impinger: a simple device for assessing the delivery of drugs from metered dose pressurized aerosol inhalers. J Pharm Pharmacol 1987; 39(12):966–72.

Meenach SA, Vogt FG, Anderson KW, Hilt JZ, McGarry RC, Mansour HM. Design, physicochemical characterization, and optimization of organic solution advanced spray-dried inhalable dipalmitoylphosphatidylcholine (DPPC) and dipalmitoyl phosphatidyl ethanolaminepoly(ethylene glycol) (DPPE-PEG) microparticles and nanoparticles for targeted respiratory nanomedicine delivery as dry powder inhalation aerosols. Int J Nanomedicine 2013; 8:275–93.

Wu X, Zhang W, Hayes D, Mansour HM. Physicochemical characterization and aerosol dispersion performance of organic solution advanced spray-dried cyclosporine A multifunctional particles for dry powder inhalation aerosol delivery. Int J Nanomedicine 2013; 8:1269–83.

Mohan M, Lee S, Guo C, Peri SP, Doub WH. Evaluation of Abbreviated Impactor Measurements (AIM) and Efficient Data Analysis (EDA) for Dry Powder Inhalers (DPIs) Against the Full-Resolution Next Generation Impactor (NGI). AAPS Pharm Sci Tech 2017; 18(5):1585–94.

Mitchell JP, Nagel MW, Wiersema KJ, Doyle CC. Aerodynamic particle size analysis of aerosols from pressurized metered-dose inhalers: comparison of Andersen 8-stage cascade impactor, next generation pharmaceutical impactor, and model 3321 Aerodynamic Particle Sizer aerosol spectrometer. AAPS Pharm Sci Tech 2003; 4(4):E54.

Schonell M, Chan-Yeung M, McLean L. Salbutamol--an effective bronchodilator. Can Med Assoc J 1972; 106(4):339–41.

LaForce C, Taveras H, Iverson H, Shore P. Albuterol multidose dry powder inhaler efficacy and safety versus placebo in children with asthma. Allergy Asthma Proc 2017; 38(1):28–37.

Mitchell J, Nagel M. Particle Size Analysis of Aerosols from Medicinal Inhalers. KONA Powder Part J 2004; 22:32–65.

Peng T, Lin S, Niu B, Wang X, Huang Y, Zhang X, et al. Influence of physical properties of carrier on the performance of dry powder inhalers. Acta Pharm Sin B 2016; 6(4):308–18.

Ohrem HL, Schornick E, Kalivoda A, Ognibene R. Why is mannitol becoming more and more popular as a pharmaceutical excipient in solid dosage forms? Pharm Dev Technol 2014; 19(3):257–62.

Allen E, Smith P, Henshaw J. Review of Particle Agglomeration. US Department of Energy; 2001.

Zeng XM, Martin GP, Marriott C, Pritchard J. Lactose as a carrier in dry powder formulations: the influence of surface characteristics on drug delivery. J Pharm Sci 2001; 90(9):1424–34.

Pilcer G, Wauthoz N, Amighi K. Lactose characteristics and the generation of the aerosol. Adv Drug Deliv Rev 2012; 64(3):233–56.

Sakagami M. In vivo, in vitro and ex vivo models to assess pulmonary absorption and disposition of inhaled therapeutics for systemic delivery. Adv Drug Deliv Rev 2006; 58(9–10):1030–60.




How to Cite

Omer, H. K., Husein, N. R., & Hamadameen, H. A. (2019). Comparison between the next generation impactor and the twin glass impinge as model pulmonary drug delivery devices. Zanco Journal of Medical Sciences (Zanco J Med Sci), 23(1), 74–80.



Original Articles