Baxter Healthcare (Deerfield, Illinois) reported results of a Phase I study that evaluated pulmonary insulin produced with Baxter’s PROMAXX microsphere technology and administered using a small, standard dry powder inhaler. Baxter presented the Phase I data in late April at the Respiratory Drug Delivery Europe 2007 Conference in Paris.
The study demonstrates that the insulin powder can be administered to the deep lung using an off-the-shelf dry powder inhaler designed for upper airway drug delivery.
A total of 30 subjects participated in the randomized, two-way crossover study conducted in Germany. Each subject received in randomized fashion a single dose of 10 International Units of insulin through subcutaneous injection (SC) in one period, and 6.5 milligrams of the inhaled insulin microspheres, called recombinant human insulin inhalation powder (RHIIP) in the other period.
RHIIP is made using Baxter’s PROMAXX formulation technology. The company says that unlike other dry powder formulations of insulin, RHIIP is 95% insulin and does not rely on the use of inactive ingredients to facilitate delivery to the deep lung, Baxter said.
No serious adverse events were reported, and no subjects withdrew from the study due to an adverse event. All adverse events were mild in severity. The most common reported treatment-emergent adverse event was phlebitis. There were no reported episodes of cough or shortness of breath in this study.
Study data show that RHIIP had a faster onset of action than SC. Duration of action and total metabolic effect were comparable. Pharmacokinetic results were in accordance with these findings: RHIIP was absorbed faster, and maximum insulin levels were reached earlier. The bioavailability of RHIIP relative to SC was more than 12%.
“These encouraging results show the bioavailability of RHIIP compare favorably with that observed for many other inhaled insulin preparations, even though the standard type of inhaler used in this study was not optimized for delivery of insulin to the deep lung,” said Dr. Tim Heise of Profil Institut fur Stoffwechselforschung (Neuss, Germany), principal study investigator. “RHIIP may have the potential to achieve even higher bioavailability through further improvements in the insulin delivery technique, and this will be the subject of further studies.”
Baxter says that PROMAXX microsphere technology offers narrow control of microsphere size. PROMAXX microspheres can be manufactured to meet formulation requirements for proteins including therapeutic monoclonal antibodies, peptides, low molecular weight drugs and nucleic acids.