Dry Powders for Inhalation Containing Monoclonal Antibodies Made by Thin-Film Freeze-Drying

Thin-film freeze-drying (TFFD) is a rapid freezing and then drying technique used to prepare inhalable dry powders from the liquid form for drug delivery to the lungs. We report the preparation of aerosolizable dry powders of monoclonal antibodies (mAbs) by TFFD. We first formulated IgG with lactose/leucine (60:40 w/w) or trehalose/leucine (75:25). IgG 1% (w/w) formulated with lactose/leucine (60:40 w/w) in phosphate buffered saline (PBS) (IgG-1-LL-PBS) and processed by TFFD was found to produce the powder with the most desirable aerosol properties. We then replaced IgG with a specific antibody, anti-programmed cell death protein (anti-PD-1 mAb), to prepare a dry powder (anti-PD1-1-LL-PBS), which performed similarly to the IgG-1-LL-PBS powder. The aerosol properties of anti-PD1-1-LL-PBS were significantly better when TFFD was used to prepare the powder as compared to conventional shelf freeze-drying (shelf FD). The dry powder had a porous structure with nanoaggregates. The dry powder had a Tg value between 39-50 °C. When stored at room temperature, the anti-PD-1 mAb in the TFFD powder was more stable than that of the same formulation stored as a liquid. The addition of polyvinylpyrrolidone (PVP) K40 in the formulation was able to raise the Tg to 152 °C, which is expected to further increase the storage stability of the mAbs. The PD-1 binding activities of the anti-PD-1 mAbs before and after TFFD were not different. While protein loss, likely due to protein binding to glass or plastic vials and the TFF apparatus, was identified, we were able to minimize the loss by increasing mAb content in the powders. Lastly, we show that another mAb, anti-TNF-α, can also be converted to a dry powder with a similar composition by TFFD. We conclude that TFFD can be applied to produce stable aerosolizable dry powders of mAbs for pulmonary delivery.