Functionalization of lactose as a biological carrier for bovine serum albumin by electrospraying

Electrohydrodynamic atomization (EHDA) is an attractive technique to make new types of composite particles for pharmaceutical use. The aim of this work is to prove that EHDA can be successfully used to attach nano/micro-particles of protein to lactose, the commonly used excipient for pulmonary delivery, keeping all the biological properties of the protein after dissolution of the complex. Bovine serum albumin (BSA) was used as a model protein. The atomization of BSA was tested with two different solvents, dimethyl sulfoxide (DMSO) and ethanol. The process using DMSO resulted in the formation of a thin layer of protein while the tests using ethanol resulted in the formation of spherical particles with mean diameters around 700 nm. Ethanol as solvent was also used to produce a composite formed by BSA adsorbed at the surface of lactose by electrostatic forces. No denaturation or significant conformational changes of the protein were observed, although an increase in the exposition of the lactose to the jet of the solution decreases the reproducibility of the method. Due to the absence of denaturation in the model protein, this new approach can be tested for the production of new formulations for dry powders for drug delivery systems.