Freeze drying of polyelectrolyte complex nanoparticles: effect of nanoparticle composition and cryoprotectant selection

Publication date: Available online 17 September 2018Source: International Journal of PharmaceuticsAuthor(s): Anita Umerska, Krzysztof J. Paluch, Maria-Jose Santos Martinez, Owen I. Corrigan, Carlos Medina, Lidia TajberAbstractThis work investigates the impact of nanoparticle (NP) composition and effectiveness of cryo-/lyo-protectants in a freeze drying process, which was employed to convert liquid dispersions of polyelectrolyte complex (PEC) NPs into completely redispersible powders. PEC NPs, with and without peptide, were produced by complex coacervation. The cryo-/lyo-protectants investigated were mannitol, trehalose (TRE) and poly(ethylene glycol) (PEG). The solid state of lyophilised powders was studied by thermal analysis and X-ray diffraction. Cytotoxicity studies were done by MTS assay and flow cytometry. The presence of a cryoprotectant was essential to achieve a successful powder reconstitution. The concentration of TRE was optimised for each type of PEC NPs. Protamine- and hyaluronate-based NPs reconstituted better than chitosan- and chondroitin sulphate-based NPs, respectively. PEG polymers were found to be more effective cryoprotectants than TRE and best results were achieved using co-freeze drying of NPs with TRE and PEG. These ternary NPs/TRE/PEG samples were crystalline, with expected better storage stability. PEG polymers were well tolerated by Caco-2 cells, with the exception of linear PEG 10 kDa. This work shows that, as regards the formulation design and ma...
Source: International Journal of Pharmaceutics - Category: Drugs & Pharmacology Source Type: research