Production of antibiotic nanoparticles using supercritical CO2 as antisolvent with enhanced mass transfer

Drug delivery systems improve the therapeutic efficacy and safety of drugs by delivering them at a controlled rate depending on the body requirements and the site of action. These systems aid in reducing the amount of drug required, the number of doses, side effects, and bioinactivation. Currently, delivery systems for drug targeting and controlled release are being developed using drug nanoparticles. Several techniques, such as spray drying and milling, have been used in the past for the manufacture of drug nanoparticles, but these methods have several disadvantages. Supercritical fluid technologies such as RESS and SAS do provide novel methods for particle formation, but in most cases, they still cannot produce particles in the nanometer range (< 300 nm) necessary for drug targeting and controlled release. In this work, we propose a technique that can produce drug particles in the nanometer range with a narrow size distribution. This new technique is a modification of the currently existing SAS technique and involves the use of a vibrating surface that atomizes the jet into microdroplets. The ultrasonic field generated by the vibrating surface also enhances mass transfer through increased mixings The new technique is demonstrated for the production of tetracycline nanoparticles as small as 125 nm in size with a narrow size distribution. Particle sizes are easily controlled using this technique by changing the vibrational intensity of the vibrating surface.