Spray-Dried Polymeric Nanoparticles for Pharmaceutics: A Review of Patents

Abstract

Polymeric nanoparticles have been the focus of several researches in the last three decades in diverse areas including the delivery of pharmaceutical, diagnostic and cosmetic agents. These nanocarriers are able to improve the bioavailability and intrinsic solubility of drugs, to target different agents to a specific location or to protect the agent against extrinsic factors, such as radiation and extreme pH conditions. Despite the high interest in the development of these formulations, they hold some disadvantages like the limited physicochemical stability, which hinders the scaling-up of the preparation methods. In this context, spray-drying techniques have been proposed to obtain powder compositions containing polymeric nanoparticles allowing this limited property to be circumvented. In this context, this review is focused on the latest patents related to obtaining spray-dried polymeric nanoparticles, which have been divided into three different groups, according to their approach: i) spray-drying solutions to obtain nanoparticles, ii) spray-drying emulsions/ dispersions to obtain nanoparticles, and iii) nanoparticles dried by spray-drying.

An Overview on Spray-Drying of Protein-Loaded Polymeric Nanoparticles for Dry Powder Inhalation

“…Thus, polymeric nanoparticles may be previously prepared in a suspension form, and further spray-dried to improve its physicochemical stability and efficacy in a long term [26,52,61,71]. Different adjuvants may be added to the nanoparticle suspension to obtain easily re-dispersible powders with a good recovery of particle size in the nanoscale [72]. Guterres et al prepared microparticles encapsulating polymeric nanoparticles by spray-drying to improve stability of the loaded drug [71].…”

“…Guterres et al prepared microparticles encapsulating polymeric nanoparticles by spray-drying to improve stability of the loaded drug [71]. Silicon dioxide was added to the formulation as a drying agent and as scaffold for the nanoparticles [72,73].…”

“…The production of nanoparticles by spray-drying is a multi-step process that requires the production of a clear homogeneous solution with one or more constituents, before spray-drying [72]. The use of an organic solution in spray-drying allows to achieve lower water content in the nanoparticle dry powder [26].…”

“…Recent developments in the spray-drying field have introduced a novel technique to prepare nanoparticles called nano spray-drying [5,52,72]. In the nano spray-drying, a membrane is attached to the spray head to generate nanoparticles with homogeneous size by piezoelectric effect.…”

“…The release rate of drugs from nanoparticles can be controlled by refining the ratios between hydrophilic polymers. Polymer concentration below 0.5% w/w increases the release of poorly water-soluble drugs in solid dispersions [72,79].…”