Effects of the conformation of PLGA molecules in the organic solvent on the aerodynamic diameter of spray dried microparticles

Effect of the Conformation of Poly(L-lactide-<i>co</i>-glycolide) Molecules in Organic Solvents on Nanoparticle Size

“…R coil and V coil were used to estimate the conformation of the polymers formed in the solvent 24,25 . These results support the previous study on microparticles 3 . It has been reported that a polymer expands in a good solvent and contracts in a poor solvent 21,24 .…”

“…To evaluate the conformation of the PLLGA molecules in the dispersed phase, a viscometer TV-20, Toki Sangyo Co., Ltd., Tokyo, Japan was employed to carry out the viscosity measurements 3 . Since viscosity is affected by temperature, all measurements were performed at 25 21 .…”

“…A mixture of dichloromethane, which is a good solvent for PLGA, and methanol, which is a poor solvent for PLGA, was used as a feed solution at an arbitrary ratio. It was shown that as the ratio of the poor solvent in the feed solution increased, the conformation of the polymer in the feed solution became more compact and the size of the prepared microparticles became smaller 3 . In this study, we aim to further control the size of the nanoparticles by using three kinds of lower alcohols, namely, methanol, ethanol, and 1-propanol, as poor solvents.…”

Drug Delivery Properties of Nanocomposite Particles for Inhalation: Comparison of Drug Concentrations in Lungs and Blood

“…Rifampicin (RFP), a semi-synthetic bactericidal antibiotic drug, was used as a hydrophobic model drug. The drug is easily quantified using highperformance liquid chromatography (HPLC), and there are already many reports focused on using PLGA to prepare RFP-filled microspheres and nanoparticles (10,(12)(13)(14)(15). RFP concentrations in the lungs and blood when nanocomposite particles were administered were confirmed by in vivo experiments using mice.…”

Three-Dimensional Culture System of Cancer Cells Combined with Biomaterials for Drug Screening

“…For example, PLGA7520 indicates a copolymer of 20,000 molecular weight, and 75 wt % PLA and 25 wt % PGA. Both the molecular weight and LA/GA ratio determine the crystallinity or glass transition temperature [ 180 ], which enables the control of the size, porosity, or stiffness of PLGA particles or scaffolds easily [ 178 , 181 , 182 , 183 , 184 ].…”