Effect of the drying process on the preparation of porous silica microspheres

Strategies for overcoming protein and peptide instability in biodegradable drug delivery systems

The global pharmaceutical market has recently shifted its focus from small molecule drugs to peptide, protein, and nucleic acid drugs, which now comprise a majority of the top-selling pharmaceutical products on the market. Although these biologics often offer improved drug specificity, new mechanisms of action, and/or enhanced efficacy, they also present new challenges, including an increased potential for degradation and a need for frequent administration via more invasive administration routes, which can limit patient access, patient adherence, and ultimately the clinical impact of these drugs. Controlled-release systems have the potential to mitigate these challenges by offering superior control over in vivo drug levels, localizing these drugs to tissues of interest (e.g., tumors), and reducing administration frequency. Unfortunately, adapting controlled-release devices to release biologics has proven difficult due to the poor stability of biologics. In this review, we summarize the current state of controlled-release peptides and proteins, discuss existing techniques used to stabilize these drugs through encapsulation, storage, and in vivo release, and provide perspective on the most promising opportunities for the clinical translation of controlled-release peptides and proteins.

Influence of drying processes on the structures, morphology and in vitro release profiles of risperidone-loaded PLGA microspheres

The purpose of this study was to investigate the influences of drying methods on the risperidone (RIS) release profiles of RIS-loaded PLGA microspheres. These microspheres were fabricated with an O/W emulsion solvent evaporation method. The wet microspheres were dried with freeze drying and vacuum drying methods. The microspheres were mono-dispersed spheres with an average diameter of 100 μm. Studies found that drying methods had great influence on the porosity, morphology, and release profiles of RIS-loaded PLGA microspheres. Specifically, the freeze-dried microspheres had higher porosity (78.46 ± 1.64%) than those vacuum-dried ones (52.45 ± 2.68%), and they showed higher RIS release rates (p < 0.05). In the accelerated release tests (45 °C), these microspheres dried under the pressures of 700 mmHg and 200 mmHg gave faster release rates than those ones dried under the pressure of 450 mmHg. Importantly, the accelerated release test (45 °C) had a high correlation with the real-time test (37 °C) (R² > 0.99). These studies exhibited a significance in the precise preparation of RIS-loaded PLGA microspheres.

Site-Selective TiO2 Coating on Asymmetric Patchy Particles

The successful fabrication of TiO₂-faced asymmetric patchy particles consisting of polystyrene and a Fe₃O₄/SiO₂/TiO₂ part is described. Such particles can be of large interest for photochemistry. The used site-selective coating approach demonstrates a modification strategy for a special patchy particle family which may have a general character. The stability of the coating has been tested under several conditions with no sign of disruption. The influence of the prepared asymmetric particles on oil/water phase mixing behavior was tested and turned out to be very diverse. Oils with low polarity (e.g., hexadecane, cyclohexane, octadecane) can form Pickering emulsions by the help of these particles; oils with high polarity (e.g., 1-octanol) form monodisperse macrodroplet systems with unusual stability.