*A Microfluidic Device as a Drug Carrier DOI: http://dx.doi.org/10.5772/intechopen.102052*

technique offers many benefits over earlier approaches, including minimal residue, the use of very few solvents, low cost, and the use of high molecular weight polymers [25]. The microdevices are made up of two flow-focusing pads that work together in a two-step procedure to make double emulsions. As a result, at low flow rates, the aqueous phase is symmetrically restricted at the initial connection point as a result of which monodisperse aqueous monomer plugs are formed. The oil phase encapsulates liquids 1 and 2 at the second connection point and creates double droplets of aqueous and monomeric phases. The composite droplets then reach a third junction where the channel cross-section is enlarged, whereby they assume spherical shapes. In the large section, conservation of mass forces the droplets to slow down significantly, thereby decreasing the spacing between successive droplets and thus decreasing the spacing between successive droplets, thereby decreasing the spacing between successive droplets [26].

Advances in drug delivery technology can improve pharmacological factors, including efficacy and bioavailability, to discover and develop more effective drugs to improve the treatment effects and quality of life of patients. Manufacturing quality control, fluctuations between product batches, and the inability to obtain physiologically relevant test results in traditional *in vitro* prescreening platforms are all obstacles to nanoparticle drug delivery [10]. Microfluidics has evolved from microliter fluid processing to nanoliter fluid processing, including multidisciplinary methods that can be used in a wide range of applications [27, 28]. Microfluidics (a method of fabrication) provides a mechanism for making highly controllable, reproducible, and scalable methods to produce nanoparticles. When compared to traditional *in vitro* culture methods, the organ-on-chip microfluidic technology provides highly relevant organ-specific testing platforms capable of biologically relevant experimental time scales while employing a fraction of the sample and media volumes [29, 30].

Microfluidic technologies provide low-cost, simple-to-use platforms to control the flow of fluids. Emulsions produced in microfluidic devices have been used in a variety of scientific applications, comprising biomedical field, chemical synthesis, fluid flow, and controlled drugs delivery. T-junctions and flow-focusing nozzles are two types of microfluidic platform devices that are used to make emulsions [31, 32]. Both procedures allow for the production of monodisperse particles as well as a wide range of emulsion sizes. Flow-focusing devices are commonly used to produce monodisperse polymer particles, both spherical and non-spherical. FF devices have been proven to generate photo-curable polymeric particles, ion-cross-linkable thermosensitive gels, polymer-encapsulated cells, and other particles in some situations [33, 34], polymerencapsulated cells [35, 36], and other particles [21, 37]. Microfluidics can be applied to polylactide particles to make the production of novel drugs easier.
