Drug-nanoencapsulated PLGA microspheres prepared by emulsion electrospray with controlled release behavior

Abstract

The development of modern therapeutics has raised the requirement for controlled drug delivery system which is able to efficiently encapsulate bioactive agents and achieve their release at a desired rate satisfying the need of the practical system. In this study, two kind of aqueous model drugs with different molecule weight, Congo red and albumin from bovine serum (BSA) were nano-encapsulated in poly (dl-lactic-co-glycolic acid) (PLGA) microspheres by emulsion electrospray. In the preparation process, the aqueous phase of drugs was added into the PLGA chloroform solution to form the emulsion solution. The emulsion was then electrosprayed to fabricate drug-nanoencapsulated PLGA microspheres. The morphology of the PLGA microspheres was affected by the volume ratio of aqueous drug phase and organic PLGA phase (Vw/Vo) and the molecule weight of model drugs. Confocal laser scanning microcopy showed the nanodroplets of drug phase were scattered in the PLGA microspheres homogenously with different distribution patterns related to Vw/Vo. With the increase of the volume ratio of aqueous drug phase, the number of nanodroplets increased forming continuous phase gradually that could accelerate drug release rate. Moreover, BSA showed a slower release rate from PLGA microspheres comparing to Congo red, which indicated the drug release rate could be affected by not only Vw/Vo but also the molecule weight of model drug. In brief, the PLGA microspheres prepared using emulsion electrospray provided an efficient and simple system to achieve controlled drug release at a desired rate satisfying the need of the practices.

Fabrication of Antimicrobial Peptide-Loaded PLGA/Chitosan Composite Microspheres for Long-Acting Bacterial Resistance

“…Within the initial 10 days, the PLGA/CS MSs underwent a quick release period with about 30% KSL-W released. This phenomenon was mainly due to the easier and faster release of KSL-W distributed near microsphere surfaces in a diffusion-controlled mode [ 26 ]. After that, the PLGA/CS MSs released about 60% KSL-W in the following 70 days in both diffusion- and degradation-controlled fashions.…”

“…However, from a technical standpoint, it is difficult to achieve desirable microspheres with uniform size distribution, high drug encapsulation, and good loading efficiency because smaller molecules can hardly enter PLGA microspheres sufficiently via conventional preparation methods. The electrospraying technique is a useful technique to prepare microspheres, embedding bioactive proteins through ejecting a polymer solution under high voltage power and ventilation conditions [ 25 , 26 ]. In addition, it is very easy to use electrospraying to completely control the drug encapsulation and size distribution of microspheres [ 26 ].…”

“…The electrospraying technique is a useful technique to prepare microspheres, embedding bioactive proteins through ejecting a polymer solution under high voltage power and ventilation conditions [ 25 , 26 ]. In addition, it is very easy to use electrospraying to completely control the drug encapsulation and size distribution of microspheres [ 26 ].…”

Effect of microsphere size on the drug release and experimental characterization of an electrospun naringin‐loaded microsphere/sucrose acetate isobutyrate (SAIB) depot

“…The degradation of microspheres is reported to divide into two progress: surface defects on the microspheres and fast erosion of the PLGA polymer . As demonstrated in a previous study, preferential degradation of the surface was observed, and poriferous microspheres were formed after the first week of incubation . Therefore, considering the microsphere drug release rate in 7 days shown in Figure 4A, where all the values are over 80%, it was not difficult to find that the first‐week degradation of the microspheres might mainly be attributed to release loss of Ng.…”

“…The progress of modern therapeutics has increased the demand for a controlled drug delivery system that is able to efficiently encapsulate bioactive agents and release them at a desired rate . Polymeric microspheres have become one of the most frequently used types of controlled‐release devices because of their versatility, relatively simple administration, and ease of fabrication .…”