ISSN: 2378-3664 Arpagaus. Int J Med Nano Res 2018, 5:026 DOI: 10.23937/2378-3664.1410026 Volume 5 | Issue 1 International Journal of Open Access Medical Nano Research REVIEW ARTICLE Pharmaceutical Particle Engineering via Nano Spray Drying - Process Parameters and Application Examples on the Laboratory- Scale Cordin Arpagaus* Check for NTB University of Applied Sciences of Technology Buchs, Institute for Energy Systems, Switzerland updates *Corresponding author: Arpagaus Cordin, NTB University of Applied Sciences of Technology Buchs, Institute for Energy Systems, Erdenbergstrasse 4, 9471 Buchs, Switzerland, Tel: +41-81-755-34-94, E-mail: [email protected] ceutical industry. Table 1 lists some examples of mar- Abstract keted pharmaceutical products processed by spray dry- Spray drying plays a crucial role in the processing of ing technology [2-8]. pharmaceutical products such as pills, capsules, and tablets as it is used to convert drug-containing liquids into dried Typically, the drug is dissolved in a polymeric carrier powdered forms. Nano spray drying is in particular used to solution and atomized into hot gas to evaporate improve drug formulation by encapsulating active ingredients in polymeric wall materials for protection and delivering the the solvent, resulting in particles containing the drugs to the right place and time in the body. The nano spray drug dispersed in an amorphous polymer matrix [9]. dryer developed in the recent years extends the spectrum of Polymers such as hydroxypropyl methylcellulose or produced powder particles to the submicron- and nanoscale its acetate succinate have become the first choice with very narrow size distributions and sample quantities in the milligram scale at high product yields. This enables for the preparation of stable solid dispersions as they the economical use of expensive active pharmaceutical are resistant to water absorption [3]. A few spray- ingredients and pure drugs. The present paper explains the dried pharmaceutical products are on the market for concept of nano spray drying in the laboratory-scale and inhalation therapies. In 2013, the US Food and Drug discusses the influence of the main process parameters on Administration approved Novartis TOBI® Podhaler™ the final powder properties like particle size, morphology, encapsulation efficiency, and drug loading. Application with 28 mg Tobramycin inhalation powder per capsule results of nano spray drying for the formulation and for the treatment of cystic fibrosis patients with encapsulation of different drugs are reviewed. Pseudomonas aeruginosa bacteria in the lungs. The Keywords Tobramycin inhalation powder is manufactured using PulmoSphere™ technology, an emulsion-based spray Nano spray drying, Pharmaceuticals, Drug encapsulation, Particle size, Powder drying process that produces spherical hollow-porous particles (Figure 1). Introduction The dried particles have a geometric mean diameter of about 1 to 2.7 μm and a mean mass diameter Spray drying is a simple, fast, continuous, and scal- of < 4 μm, which is ideal for delivering the drug to able drying technology that is well established in the the lower respiratory [5,6]. Spray dried powder pharmaceutical industry for excipient production, mi- consists of 28 mg Tobramycin active ingredient with croencapsulation, or granulation [1]. Many pharma- distearoylphosphatidylcholine calcium chloride and ceutical products such as pills, capsules, and tablets are sulfuric acid for pH adjustment. The drug is packaged processed in dried powdered form. Progress was made in a hypromellose capsule containing 28 mg of active in introducing spray-drying technology to the pharma- ingredient each. The capsules are stored individually Citation: Arpagaus C (2018) Pharmaceutical Particle Engineering via Nano Spray Drying - Process Parameters and Application Examples on the Laboratory-Scale. Int J Med Nano Res 5:026. doi. org/10.23937/2378-3664/1410026 Accepted: December 03, 2018: Published: December 05, 2018 Copyright: © 2018 Arpagaus C. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Arpagaus. Int J Med Nano Res 2018, 5:026 • Page 1 of 15 • DOI: 10.23937/2378-3664.1410026 ISSN: 2378-3664 Table 1: Examples of FDA-approved medicaments that use spray drying technology as preparation method. HPMC: Hydroxypropyl Methylcellulose; HPMCAS: Hydroxypropyl Methylcellulose Acetate Succinate; DSPC: Distear-ylphosphatidylcholine (data summarized from [2-8]). FDA Trade name Drug Application Polymer, Excipient Maximum drug dose Company approval Immunosuppressant Astellas Prograf Tacrolimus (prevents organ HPMC 5 mg per capsule 1994 Pharma rejection) Mannitol, glycine, Pfizer/ Exhubera Insulin Diabetes 1 or 3 mg per capsule 2006 sodium citrate Nektar 100 or 200 mg per Intelence Etravirine HIV medicine HPMC Janssen 2008 tablet Immunosuppressant Zortress Everolimus (prevents organ HPMC 0.75 mg per tablet Novartis 2010 rejection) Aridol/Osmohale, - Asthma/ Cystic fibrosis Mannitol 5 to 40 mg per capsule Pharmaxis 2010 Bronchitol Incivek Telaprevir Hepatitis C HPMCAS 375 mg per tablet Vertex 2011 Kalydeco Ivacaftor Cystic fibrosis HPMCAS 150 mg per tablet Vertex 2012 DSPC, calcium TOBI Podhaler Tobramycin Inhalation therapy chloride, sulfuric 28 mg per capsule Novartis 2013 acid Bleeding control during Fibrinogen/ 79 mg/726 IU per gram Nova Raplixa - 2016 surgery Thrombin powder Laboratories Figure 1: Tobramycin inhalation powder. (A) Scanning electron microscope pictures of hollow and porous PulmoSphere™ particles [5,6], (C) Novartis TOBI® Podhaler™ for dry powder inhalation depicted with day’s supply of Tobramycin inhalation powder with 2 separate blister packs of 4 × 28 mg capsules [5]. in aluminum blister packs of four to protect them from storage stability at room temperature. The aerosolized moisture in the environment. Pharmaxis commercialized insulin had a mass median aerodynamic diameter of spray dried inhalable mannitol (sugar alcohol) powders approximately 3 μm. The spray-dried insulin powder Aridol/OsmohaleTM and BronchitolTM in 2011 and 2012 was packaged in blisters containing 1 mg or 3 mg of for diagnosis of asthma by detecting active airway insulin. Despite the promise of a new delivery system, inflammation through measuring bronchial hyper- Exubera was not profitable in the insulin market and the responsiveness [7]. Mannitol is crystalline after spray product was withdrawn in 2007 because of low sales. drying and physically stable due to its low glass transition New strategies for the administration of inhaled insulin temperature. It rehydrates the airway/lung surface and are being further investigated. promotes a productive cough. Bronchitol dry powder In May 2015, the FDA approved Raplixa, the first helps to increase mucus clearance and improves the lung function and the quality of life of people living with sterile, spray dried fibrin seal powder used to control cystic fibrosis. adult bleeding during surgery [8]. The powder is applied to the sampling site directly from the vial or by using Already in 2006, Exubera® (Pfizer/Nektar Therapeutics) a low-pressure spray device. The fibrin sealant then became the first inhaled human insulin approved for dissolves in the blood and begins to clot the blood. use in type 1 or type 2 diabetes [8]. Exubera powder Raplixa comprises spray-dried thrombin and spray- was prepared by spray drying 60% recombinant human dried fibrinogen, which are aseptically mixed and filled insulin mixed with glycine, mannitol, and sodium into a single vial. Each gram of Raplixa contains 79 mg citrate as stabilizers. The spray dried powders exhibited fibrinogen and 726 IU thrombin. This eliminates the good flowability, low moisture content, and good need to combine fibrinogen and thrombin before use Arpagaus. Int J Med Nano Res 2018, 5:026 • Page 2 of 15 • DOI: 10.23937/2378-3664.1410026 ISSN: 2378-3664 and the product can be stored at room temperature. [10,14,23,25,26]. Nano spray drying enables the encap- Commercial supplies of Raplixa sealing powder are sulation of active ingredients in polymeric wall materi- produced at the sterile production facilities of Nova als providing enhanced environmental protection (e.g. Laboratories by aseptic spray drying. against oxidation, light, and temperature), stability, From a technological point of view spray drying handling, storage, and controlled drug release proper- offers flexibility in particle formulation. By tuning the ties. The nanonization and structural change improves spray drying parameters, it is possible to manipulate the the particle solubility and redispersibility of the final particle properties, e.g. particle size, shape, morphology, drug product in aqueous solutions. surface roughness, or surface composition. This study explains the concept of nano spray drying, In the course of the rapid progress of nanoencapsula- the influence of the main process parameters on the tion techniques, nano spray drying technology has also powder properties (e.g. particle size, morphology, developed, in particular at Buchi Labortechnik AG (Swit- encapsulation efficiency, drug loading), and discusses zerland), with the development of the Nano Spray Dryer different pharmaceutical applications realized in the B-90 [10-14]. The laboratory-scale nano spray dryer en- laboratory-scale. ables the formulation of drugs with solid colloidal par- Process