Purpose
A major challenge in ophthalmic drug delivery is overcoming the rapid and effective clearance of drug from the target site(s) such as the ocular surface, subconjunctival space, or posterior segment. It has been shown that PLGA particles can act as biodegradable, sustained drug delivery systems for the eye, opening up the possibility for longer-lasting, more efficient dosage forms. However, traditional methods for PLGA nano- and microparticle preparation offer poor control over polydispersity and shape/size, which can result in sub-optimal particle reproducibility, product safety, and efficacy. Here, we demonstrate the utility of PRINT micromolding technology to produce monodisperse, shape-specific nano- and microparticles for use in ocular drug delivery. We encapsulate difluprednate in these particles to demonstrate high loadings and encapsulation efficiency.
Methods
Biodegradable nano- and microparticles loaded with difluprednate were fabricated using the PRINT™ technology. Particle morphology and size were determined with Scanning Electron Microscopy (SEM) and Dynamic light scattering (DLS). Drug retention in the particles was monitored at 37C in 1X PBS using an HPLC method.
Results
Polymer-difluprednate micro- and nanoparticles were fabricated with control over shape, size, charge, and drug loading (Figure 1). Particles were fabricated in a range of sizes from 200 nm up to 3 mm. Encapsulation efficiencies up to 95% for Difluprednate in microparticles were demonstrated. The ability of the particles to retain and release difluprednate over time was determined in a PBS pH=7.4 solution.
Conclusions
We have shown that PRINT micromolding can be used to reproducibly formulate polymer/difluprednate into particles with specific size and shape for ophthalmic drug delivery applications, with high loading and high drug encapsulation efficiency. These results demonstrate that PRINT technology is a versatile alternative to traditional methods for nano- and microparticle production that may offer superior control of particle size, loading or other properties.