Analysis of droplet displacement during transport of polydisperse emulsion as drug carriers in microchannels

Drug transport in human body is often intensified by various carriers. The simplest and highly effective are emulsions. In these liquids, one phase is dispersed in other in the form of droplets, in which active substance is often dissolved. In existing application of such liquids as carriers, monodispersity of such systems has been a very important parameter, because when all droplets have same size, it is relatively easy to predict drug release time. However, monodisperse emulsion production on an industrial scale is expensive and technologically quite difficult. Therefore, it would be more reasonable to use polydisperse emulsions. However, mechanism of drug release from such carriers is more complicated and difficult to conduct. When emulsion droplets of different sizes pass through microchannels, i.e., blood vessels, individual droplets' transport velocity is different and interdependent. The ability to predict rate at which individual droplets travel through microchannels will enable control of drug release depending on emulsion parameters. This work presents a detailed analysis of polydisperse emulsion transport through a single microchannel. Dependence of individual droplets velocity on their diameter and position relative to flow axis and influence of these parameters on droplet transport trajectories were studied. These studies were conducted for five liquid flow rates and three emulsion concentrations. As a result of this work, some generalization approach was proposed to estimate droplet transport velocity depending on their position in channel based on reference to single-phase flow. This work may find application in pharmaceutical industry for design of cheaper drug manufacturing technologies.

Automated summary

Drug transport in the human body can be intensified by using emulsions as carriers. While monodisperse emulsions have been commonly used due to their predictable drug release time, polydisperse emulsions are more cost-effective for industrial production. However, the mechanism of drug release from polydisperse emulsions is more complex. This study analyzes the transport of polydisperse emulsions through microchannels and proposes a method to predict droplet transport velocity based on their position in the channel.