Using ultrasound to formulate nanotherapeutics
The structure of drug particles, and not only their molecular composition, plays an important role in determining their biological fate and therapeutic efficacy (1). Ultrasound is a promising technology that enables controlling particle size at the micro- and nanoscale (2). Furthermore, ultrasound can be used for separating and concentrating particulate sub-populations according to their dimensions and physical properties. The ability to tune the frequency and amplitude of ultrasonic waves makes this technology attractive for dealing with poorly soluble drug candidates and ensures structural integrity when formulating delicate biomolecules, such as proteins and nucleic acids.
Advancements in the fields of pharmaceutical chemistry and synthetic biology are generating new classes of therapeutic compounds. In many cases, formulating these compounds into aqueous dispersible particles is a prerequisite for proper in vitro and in vivo evaluation. Drug formulations can protect compounds from degradation, increase solubility, and extend circulation time. Advanced formulation technologies are also capable of targeting specific tissues and regulating the drug release profile at the target site. Formulating a drug usually requires co-surfactants for stabilizing the final package. In addition, a source of energy, such as ultrasound, milling, extrusion or microfluidics, is necessary many times to control particle size. This prospective discusses the important role ultrasound is playing in fabricating micro- and nanoscale drug formulations.
PARTICLE SIZE AFFECTS BIODISTRIBUTION
The size of drug particles/formulations affects their biodistribution. In humans, nanoscale drug delivery systems, injected intravenously, target tumors and reduce side-effects by circumventing functional healthy tissue ...