Impact of crystalline and amorphous matrices on successful spray drying of siRNA polyplexes for inhalation of nano-in-microparticles.

ABSTRACT: To develop stable and inhalable dry powder formulations with long shelf life, we spray dried polyplexes consisting of siRNA and a polyethylenimine based block copolymer in presence of mannitol or trehalose. We investigated the effect of inlet (T-In) and outlet (T-Out) temperature on the recovery of siRNA as well as adsorption effects within the tubing material. Choosing a low abrasion silicon tubing prevented siRNA loss due to adsorption. Mannitol and trehalose formulations preserved siRNA integrity regardless of excipient concentration and temperature at T-Out below the siRNA melting temperature. Trehalose formulations allowed full siRNA recovery whereas mannitol formulations resulted in spray drying induced losses of ~20 % siRNA and of 50-60 % polymer. Mannitol formulations showed optima

SUBMITTER: Keil TW 

PROVIDER: S-EPMC7611418 | biostudies-literature | 2021 Jun

REPOSITORIES: biostudies-literature