The Influence of Drug–Polymer Solubility on Laser-Induced In Situ Drug Amorphization Using Photothermal Plasmonic Nanoparticles

In this study, laser-induced in situ amorphization (i.e., amorphization inside the final dosage form) of the model drug celecoxib (CCX) with six different polymers was investigated. The drug–polymer combinations were studied with regard to the influence of (i) the physicochemical properties of the polymer, e.g., the glass transition temperature (Tg) and (ii) the drug–polymer solubility on the rate and degree of in situ drug amorphization. Compacts were prepared containing 30 wt% CCX, 69.25 wt% polymer, 0.5 wt% lubricant, and 0.25 wt% plasmonic nanoparticles (PNs) and exposed to near-infrared laser radiation. Upon exposure to laser radiation, the PNs generated heat, which allowed drug dissolution into the polymer at temperatures above its Tg, yielding an amorphous solid dispersion. It was found that in situ drug amorphization was possible for drug–polymer combinations, where the temperature reached during exposure to laser radiation was above the onset temperature for a dissolution process of the drug into the polymer, i.e. TDStart. The findings of this study showed that the concept of laser-induced in situ drug amorphization is applicable to a range of polymers if the drug is soluble in the polymer and temperatures during the process are above TDStart.

Towards a predictive model for polymer solubility using the noncovalent interaction index: polyethylene as a case study

A novel solubility descriptor is presented based on the non-covalent interaction index, providing information on the solute’s inter- and intramolecular interactions, and its conformation. Polyethylene in (anti)solvent is used as a case-study.

Polymer solubility in ionic liquids: dominated by hydrogen bonding

The product of H-bond acidity (α) and basicity parameter (β) reflects the complementary nature of the H-bonding interactions. Strong cross-association and weak self-association favor the solubility of polymer in ILs, therefore the product of ΔαΔβ < 0.

Aromatic polyamide nonporous membranes for gas separation application

Polymer membrane-based gas separation is a superior economical and energy-efficient separation technique over other conventional separation methods. Over the years, different classes of polymers are investigated for their membrane-based applications. The need to search for new polymers for membrane-based applications has been a continuous research challenge. Aromatic polyamides (PAs), a type of high-performance materials, are known for their high thermal and mechanical stability and excellent film-forming ability. However, their insolubility and processing difficulty impede their growth in membrane-based applications. In this review, we will focus on the PAs that are investigated for membrane-based gas separations applications. We will also address the polymer design principal and its effects on the polymer solubility and its gas separation properties. Accordingly, some of the aromatic PAs developed in the authors’ laboratory that showed significant improvement in the gas separation efficiency and placed them in the 2008 Robeson upper bound are also included in this review. This review will serve as a guide to the future design of PA membranes for gas separations.

Recycling of multilayer plastic packaging materials by solvent-targeted recovery and precipitation

Many plastic packaging materials manufactured today are composites made of distinct polymer layers (i.e., multilayer films). Billions of pounds of these multilayer films are produced annually, but manufacturing inefficiencies result in large, corresponding postindustrial waste streams. Although relatively clean (as opposed to municipal wastes) and of near-constant composition, no commercially practiced technologies exist to fully deconstruct postindustrial multilayer film wastes into pure, recyclable polymers. Here, we demonstrate a unique strategy we call solvent-targeted recovery and precipitation (STRAP) to deconstruct multilayer films into their constituent resins using a series of solvent washes that are guided by thermodynamic calculations of polymer solubility. We show that the STRAP process is able to separate three representative polymers (polyethylene, ethylene vinyl alcohol, and polyethylene terephthalate) from a commercially available multilayer film with nearly 100% material efficiency, affording recyclable resins that are cost-competitive with the corresponding virgin materials.

The Role of Solubility in Thermal Field Flow Frac-tionation – A Revisited Theoretical Approach for Tuning the Separation of Chain-Walking Polymerized Polyethylene

The influence of the polymer solubility on the separation efficiency in thermal field-flow fractionation (ThFFF) was investigated for a polymer model system of differently branched chain walking polyethylenes in five different solvents, which were selected depending on their physical parameters. The understanding of polymer thermal diffusion has been elucidated using a revisited approach based on the latest thermal diffusion prediction model by Mes,<br>Kok and Tijssen combined with the Hansen solubility theory. Thereby, a significant improvement in the precision of the thermal diffusion prediction and the separation efficiency has been achieved by implementation of the temperature dependency on Hansen solubility parameters. In addition, we demonstrate a method for validation of the segmental size of polymer chains with varying topology by using the revisited thermal diffusion prediction approach in inverse mode and experimental thermal diffusion data.

The Role of Solubility in Thermal Field Flow Frac-tionation – A Revisited Theoretical Approach for Tuning the Separation of Chain-Walking Polymerized Polyethylene

The influence of the polymer solubility on the separation efficiency in thermal field-flow fractionation (ThFFF) was investigated for a polymer model system of differently branched chain walking polyethylenes in five different solvents, which were selected depending on their physical parameters. The understanding of polymer thermal diffusion has been elucidated using a revisited approach based on the latest thermal diffusion prediction model by Mes,<br>Kok and Tijssen combined with the Hansen solubility theory. Thereby, a significant improvement in the precision of the thermal diffusion prediction and the separation efficiency has been achieved by implementation of the temperature dependency on Hansen solubility parameters. In addition, we demonstrate a method for validation of the segmental size of polymer chains with varying topology by using the revisited thermal diffusion prediction approach in inverse mode and experimental thermal diffusion data.