استنشاق الإنسولين بدل حقنه
طورت شركة أميركية لصناعة الأدوية جهازا صغيرا لاستنشاق مسحوق الإنسولين سيمكن مستخدميه من مراقبة مستوى السكر في دمهم دون اللجوء لحقن الإنسولين. وتنتظر مانكايند كوربوريشن, ومقرها كاليفورنيا, موافقة إدارة الغذاء والدواء الأميركية للبدء في تسويق الجهاز والمسحوق المصاحب له. ويقول المدير المالي ماثيو بفيفر إن مسحوق الإنسولين الذي أطلقت عليه شركته اسم "آفريسا" يذوب داخل الرئتين بعيد استنشاقه, قبل أن ينساب داخل الدورة الدموية. ومن المعروف أن استخدام الإنسولين أو أي عقار آخر لمراقبة مستوى السكر في الدم، يساعد مرضى السكري في تجنب المضاعفات الخطيرة لهذا المرض والتي تشمل أمراض القلب والفشل الكلوي والعمى وتلف الأعصاب.
يُذكر أن استخدام الإنسولين في شكل مادة تستنشق ليس جديدا, إذ كانت شركة للأدوية قد أدخلت عام 2006 إلى الأسواق منتجا من هذا النوع أسمته أكسوبيرا. لكن جهاز الاستنشاق المصاحب للمسحوق كان كبيرا ومزعجا, وهو ما يرى بعض المحللين أنه تسبب في عزوف الناس عنه مما اضطر الشركة المصنعة له إلى سحبه من الأسواق سنتين فقط بعد موافقة إدارة الغذاء والدواء عليه. غير أن فرص نجاح منتوج مانكايند الجديد تبدو أفضل نظرا لصغر حجم الجهاز، وسرعة مفعول مسحوق الإنسولين المصاحب له.
Alternative Insulin Delivery Methods
Will Inhaled Insulin Really Take Your Breath Away?
by John Walsh, P.A., C.D.E.
The FDA approved the first inhaled version of insulin called Exubera from Pfizer Inc. in January 2006. It became available in September 2006, 84 years after the first insulin injections were given. By October 2007, Pfizer announced it would be dropping Exubera, citing that the drug had failed to gain the acceptance of patients and physicians
Background
Over the years, various attempts have been made to capture the $3 billion injected insulin market. Three alternative sites of delivery have fared well in the competition: into upper nasal pathways or the lungs and through the stomach.
Delivery of an insulin pill through the stomach has two hurdles to overcome: getting intact insulin molecules past acidity and digestive enzymes in the stomach and intestines, and then opening the intestinal membranes to insulin transport. These problems have stymied researchers for at least 40 years, although a new novel approach discussed below offers some hope.
Delivery of insulin to the small bath towel size area of the upper nasal airways suffers from poor transport across the nasal membranes. Delivery this way requires very large doses of insulin or use of a chemical to enhance insulin transport. Chemicals used to enhance insulin transport often cause nasal irritation and a runny nose. Even a mild cold or stuffiness could easily change the intended insulin dose. About 100 units of insulin must be deposited into the nose to deliver 10 units into the blood. Insulin production costs would seem prohibitive except that a similar ratio applies to lung delivery, a method that is rapidly progressing.
Compared to nasal delivery, transport of insulin through the lungs allows delivery across a surface area the size of a singles tennis court. Absorption into the bloodstream occurs through the thin alveolar walls of the lungs. This appears to be the most promising approach for delivery at this time. However, there is concern about the long-term effects of inhaling a growth protein into the lungs. It is hoped the large surface area over which it is spread will minimize negative effects, but small decreases in oxygen transport have already been noted in some research studies.
Several companies are working on providing inhaled insulin with varioius delivery systems.
Eli Lilly - AIR Insulin
Eli Lilly is seen as the next company to step into the inhaled insulin market. Its AIR Insulin is expected to be submitted for approval in 2009. The AIR Insulin System is currently undergoing Phase III clinical















