Glycemic Profile in Rats After Pulmonary Administration of a Pure Insulin Powder

Francesca Buttini,¹ Veronica Chierici¹, Eride Quarta¹, Lisa Flammini¹, Adryana Rocha Clementino¹, Susana Ecenarro², Massimiliano Tognolini¹, Elisabetta Barocelli¹, Paolo Colombo¹ & Ruggero Bettini¹

¹Food and Drug Department, University of Parma, Parco Area delle Scienze 27a, 43124, Parma, Italy

²Qualicaps Europe, S.A.U., Alcobendas, Madrid, Spain

Summary

The purpose of this study was to investigate the chemical stability and respirability of a pure insulin spray-dried (Ins_SD) powder. Moreover, the glycemic plasma profile of rats was measured after pulmonary insufflation of Ins_SD and Afrezza^® at a dose of 10 IU/Kg.

The results of this study show that a pure insulin pulmonary powder (Ins_SD), produced by spray drying from an acid aqueous solution of the peptide, presented a high respirable fraction (FPF=91.5%) and favourable stability behaviour. The powder, filled into HPMC Quali-V^®-I capsules together with the PVC-PVDC packaging material, showed long term stability at room temperature whilst maintaining good aerodynamic performance. The in vivo study was conducted in rats and the glycemic plasma profile was determined after pulmonary insufflation of Ins_SD and Afrezza^® powder. These profiles resulted to be similar to each other when the powder was administered and both of them were similar to the glycemic plasma profile registered after the subcutaneous insulin solution administration.