Authors: T. Panagiotou, S.V. Mesite, J.M. Bernard, K.J. Chomistek and R.J. Fisher
Affilation: Microfluidics, United States
Pages: 688 - 691
Keywords: polymers, nanosuspensions, PLGS, drug delivery, microfluidizer
Two techniques are reported here that can create nano-suspensions of many different polymers types with varying particle sizes by controlling the formulation and process variables. Microfluidics Reaction Technology (MRT) was used with the solvent anti/solvent precipitation technique. Particle size distribution can be controlled by varying parameters such as processing pressure, degree of supersaturation and the ratio of solvent and anti-solvent streams. The solvent emulsion evaporation technique was implemented using a Microfluidizer Processor; i.e., dissolving a polymer in a solvent, creating a nanoemulsion with an immiscible continuous phase, then solvent evaporation to produce the nanosuspension. Particle size distributions can be controlled by varying process parameters and/or formulation. Nanosuspensions in the range of 50-500 nm with many different polymers have been created successfully using both techniques. Poly(epsilon-caprolactone) (PCL) and poly(D,L-lactide-co-glycolide) (PLGA) are two polymers that have been extensively used for parenteral drug delivery. A PCL suspension with a mean particle size of 220nm was created using MRT by mixing a 20 mg/ml (PCL/acetone) solvent stream with water at a ratio 1:10 (solvent:anti-solvent). PCL nanosuspensions have also been created by dissolving the PCL in methylene chloride, forming an emulsion in water and then vaporizing the solvent.