Chougule Mahavir B, Padhi Bijay K, Jinturkar Kaustubh A, Misra Ambikanandan
TIFAC-CORE in NDDS, Pharmacy Department, Faculty of Technology and Engineering, The Maharaja Sayajirao University of Baroda, Kalabhavan, Vadodara- 390 001, Gujarat State, India.
Recent Pat Drug Deliv Formul. 2007;1(1):11-21. doi: 10.2174/187221107779814159.
Development of dry powder inhalers involves powder recrystallization, formulation, dispersion, delivery, and deposition of the therapeutic agent in different regions of the airways in prophylaxis/ treatment/ diagnosis of pulmonary and systemic disorders. Conventional powder production by crystallization and milling has many limitations resulting into development of alternative techniques to overcome the problems. In the last decade many patents have been filed claiming improvement in aerosol performance of dry powder inhalers through the use of (i) incorporation of fines of carrier particles to occupy active sites on the surface and use of hydrophobic carriers to facilitate deaggregation through reduced surface energy and particle interaction (ii) reducing aerodynamic diameters through particle engineering and incorporating drug into porous or low particle density, and/or (iii) preparing less cohesive and adhesive particles through corrugated surfaces, low bulk density, reduced surface energy and particle interaction and hydrophobic additives. Moisture within dry powder inhaler (DPI) products has also been shown to influence aerosol performance via capillary force and electrostatic interaction. Better understanding of particle forces and surface energy has been achieved by the use of sophisticated analytical techniques. Understanding the intricacies of particle shape and surface properties influencing specific lung deposition has been further facilitated by the availability of newer and advanced softwares. A critical review of recent patents claiming different approaches to improve lung deposition of dry powder inhalers will help in deciding the focus of the research in the area of technological gaps.
干粉吸入器的研发涉及药物重结晶、制剂、分散、递送以及治疗剂在气道不同区域的沉积，用于预防/治疗/诊断肺部和全身性疾病。传统的通过结晶和研磨生产粉末存在许多局限性，因此需要开发替代技术来克服这些问题。在过去十年中，许多专利申请声称通过以下方式改善干粉吸入器的气溶胶性能：（i）加入载体颗粒细粉以占据表面活性位点，并使用疏水性载体通过降低表面能和颗粒间相互作用来促进解聚；（ii）通过颗粒工程减小空气动力学直径，并将药物掺入多孔或低颗粒密度的材料中；和/或（iii）通过波纹表面、低堆积密度、降低表面能和颗粒间相互作用以及疏水性添加剂制备粘性和粘附性较小的颗粒。干粉吸入器（DPI）产品中的水分也已被证明会通过毛细管力和静电相互作用影响气溶胶性能。通过使用复杂的分析技术，人们对颗粒力和表面能有了更好的理解。新型先进软件的出现进一步促进了对影响特定肺部沉积的颗粒形状和表面性质复杂性的理解。对近期声称采用不同方法改善干粉吸入器肺部沉积的专利进行批判性综述，将有助于确定该技术差距领域的研究重点。
