Stability of Novel Pain Therapy Tetrapeptide TPI-23 in Technosphere® Inhalation Powder and
Identification of Related-Compounds by Liquid Chromatography/Mass Spectrometry
Y. Livson, E. Harris, K. Fabio, J. Guarneri
MannKind Corporation
Purpose
To evaluate the stability of TPI23 tetrapeptide WsSF-NH2 under room temperature and accelerated conditions in a Technosphere inhalation powder using HPLC, and to identify the major related-compounds present using LC/MS. Methods
TPI23/Na2FDKP Technosphere inhalation powder was prepared at 50% weight API and placed on stability under room temperature and accelerated stability conditions in open container and inhalation cartridges. LC/UV separation was carried out on a Phenomenex Kinetex 2.6 C18 column (150x3.0mm) column at a flow rate of 0.5mL/min with an analysis time of 50 minutes. Compounds were eluted using a linear gradient consisting of mobile phase A of water/tetrahydrofuran/trifluoroacetic acid/ammonium hydroxide (970/30/1/1 (v/v/v/v)) and mobile phase B of acetonitrile/methanol/isopropanol/trifluoroacetic acid (850/150/30/1 (v/v/v/v)). Initial assay and stability analyses were conducted on a Waters 2695 Separations Module equipped with a Waters 2487 Dual Absorbance Detector. Related- compounds were identified using HPLC coupled with an Agilent 1100 Trap XCT mass spectrometer and an Agilent 6210 TOF mass spectrometer. ESI mass spectra were acquired in positive ion mode with full scan monitoring. TPI23 was subjected to forced degradation conditions to confirm the identity of the impurities formed in the inhalation powder during the stability study.
Results
Samples stored at room temperature lost 3.3% TPI23 assay after 16 weeks in an open container and 0.7% assay after 4 weeks in cartridges. Samples stored under accelerated conditions were most susceptible to degradation, with TPI23 assay losses after 4 weeks of 7.6% (open dish) and 8% (cartridges). Five major impurities (A-E) were present at more than 0.15 area% (ADE increased, BC remained constant).
Conclusion
TPI23 in a 50% weight Technosphere inhalation powder was stable (>96%) for up to 16 weeks when stored at room temperature, whereas samples stored for 4 weeks under accelerated stability conditions lost about 8% API. Using LC/MS and forced degradation experiments, five related-compounds were identified.
Acknowledgement: TPI-23 was discovered by the Torrey Pines Institute for Molecular Studies, Port St. Lucie, FL.
abstracts.aaps.org/Verify/aaps2013/postersubmissions/T3083.pdf