Nektar Therapeutics

The active inhaler made by Nektar Therapeutics (formerly Inhale Therapeutic Systems, United States), called Pulmonary Delivery System (PDS), mechanically compresses a fixed volume of air required for delivery and dispersion of a premetered dry-powder unit dose by a spring-loaded pump (Fig. 8.10). Generation of the respirable aerosol cloud thus is independent of the inspiration effort exerted by the patient. The aerosol is generated in a transparent holding chamber that acts as a spacer from which the patient inhales the standing cloud of particles (Patton 1997). The PDS device is actually close to market for inhaled delivery of insulin under the trade name Exubera. 

Figure 8.10 PDS device developed by Nektar Therapeutics for pulmonary delivery of insulin.

Figure 8.13 Scanning electron micrograph of spray-dried PulmoSol particles (left) and PulmoSpheres particles (right), both developed by Nektar Therapeutics. [From Peart and Clarke (2001). Reproduced with permission from Russell Publishing.]...

Activated PEGs are available commercially from many sources, in particular Nektar Therapeutics, which now supplies the starting material for most such drug products that are FDA approved or in advanced clinical development. 

Stevenson, C. Hastedt, J.E. Lehrman, S.R. Chiang, H.S. Bennett, D.B. Lesikar, D. Yang, B. Gong, D. Cabot, K. Inhaleable spray dried 4-helix bundle protein powders having minimized aggregation. US patent 6,569,406, Aug 7, 2001, Nektar Therapeutics San Carlos, CA. 

Herm E. Snyder Nektar Therapeutics, San Carlos, California, U.S.A. 

FIGURE 2 Clinical spray drying facility. Source Courtesy of Nektar Therapeutics. 

The authors would like to thank the following people at Nektar Therapeutics whose work contributed to this chapter Andrew Boeckl. Dr. Christopher Varga, and Dr. Zhuoxiong Mao. 

Bennett DB, K. BT, Snyder HE, Platz RM, Inventors Nektar Therapeutics, Inc., assignee. Spray drying process control of drying kinetics. US patent 20030044460, 2000. 

Methoxy poly(ethylene) glycol butyraldehyde (MW 2,000), mPEG-SH (MW 2,000) (all from Nektar Therapeutics, Huntsville, AL). 

Much interest has been focused recently on developing delivery systems that deaggregate the powder [63], for this effectively minimizes formulation development work. Some of these systems are extremely complex in operation and may prove difficult to achieve in everyday operations. In addition, some designs that have already been achieved (e.g., Nektar Therapeutics Enhance ... 

The preparation of this book would not be possible without the enthusiastic and timely contributions of various experts in supercritical fluid processes. The authors have summarized various areas of research while sharing their own experience in the field. We are also indebted to the expert staff at Marcel Dekker, Inc., for their assistance in the preparation of this book. Finally, we are grateful for the support of our colleagues and collaborators at Ferro Corporation, Nektar Therapeutics, Bradford University, and the University of Nebraska Medical Center. We hope that this compendium will serve some of your pharmaceutical product development needs, and we look forward to your feedback. 

A third area to consider is the generation of an enhanced product that adds value to the original finished dosage form. Product enhancements include, for example, other forms of dehvery (e.g., transder-mal, nasal, inhalable, etc.) or new formulations. Examples among the biopharmaceuticals are the development of inhaled insulins, e.g., Exubera currently in phase III clinical trials developed by Nektar Therapeutics, Pfizer, and Aventis (admittedly, this work is not driven by a potential generic threat, but primarily by the enormous market potential of an insuhn that does not have to be injected) (see also Part VI, Chapter 2). 

Insulin inhalation—Pfizer/Nektar therapeutic HMR 4006, inhaled PEG-insulin—Nektar, PEGylated insurin—Nektar. Drugs. R.D. 5 166-170. 

J.M. Harris, A. Kozlowski, L. Guo, Method of preparing carboxylic acid functionalized polymers. U. S. Patent 8067505, assigned to Nektar Therapeutics, November 29,2011. 

M.D. Bentley, X. Zhao, X. Shen, L. Guo, Sterically hindered poly(ethylene glycol) alkanoic acids and derivatives thereof U. S. Patent 7405266, assigned to Nektar Therapeutics AL Corporation, July 29,2008. 

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