Microparticle Depots Design and Development Manufactured by API alone or in combination with protective and rate control materials, particulates can take the form of matrix-like microspheres or microcapsules with a unique core/shell structure. Depots typically consist of solid polymer microspheres physically produced from biodegradable polymers. Once formulated, these particles are typically lyophilized or freezedried to produce a stable dry powder, which remains in a dry state until they are bound to the diluent prior to administration. Because depots are parenteral or injectable, they must be provided in sterile form, requiring endsterilization or aseptic manufacturing techniques. Once injected, depot formulations will degrade over time, usually spanning weeks to months.
Fig.1 Microparticle Depots mediate local nanoparticle release and subsequent intracellular delivery of nucleic acid to local cell populations. (Garland et al., 2019)
Microparticle Formulation Development CD Formulation can perform microparticle formulation development by adjusting polymer selection, particle size, and drug loading volume. When preparing depots from bioresorbable polymers, precise polymer chemistry and molecular weights need to be explored and optimized. Our formulators work closely with analysts to ensure polymer and API compatibility and to determine that there is no negative impact on the performance of either. Design of Microparticle Depots Particle size distribution (PSD) can have a significant impact on performance; if the particles in a long-acting injectable are polydispersed, meaning there is a wide range of particle sizes in the formulation, product performance will vary from dose to dose. Finding the right PSD is aided by formulation expertise and process optimization as well as design of experiments (DoE). Reference 1. Garland, Kyle M., et al. Microparticle depots for controlled and sustained release of endosomolytic nanoparticles[J]. Cellular and Molecular Bioengineering, 2019, 12(5): 429442. Source: https://www.formulationbio.com/microparticle-depots-design-and-developmentservices.html