Glassy state molecular mobility and its relationship to the physico-mechanical properties of plasticized hydroxypropyl methylcellulose (HPMC) films

Abstract

Graphical abstract

New insights into the effects of porosity, pore length, pore shape and pore alignment on drug release from extrusionbased additive manufactured pharmaceuticals

“…This increased extruded filament width with increasing drug loading may be due to the reduced thermoviscosity of the material during printing. Amorphous ibuprofen has a low glass transition temperature (𝑇 𝑔  -50°C) and can substantially plasticise the amorphous portion of PCL during printing [36] . The presence of melted ibuprofen in PCL disrupted the recrystallisation and solidification of PCL after deposition and led to wider spread of the material to give the wider extruded filament width.…”

Stimuli‐responsive mechanical properties in polymer glasses: challenges and opportunities for defense applications

“…1 The conclusive influence of chain mobility has been observed by marked increases in response times for polymeric solutions, when compared to small-molecule systems. 32,33 When the stimuli-responsive moieties are further tethered to polymer chains, the reaction rates/response times decrease as reaction sites are constrained by the slower relaxation modes of the polymer chain as compared to the small-molecule analogue. In addition, polymer glasses exhibit notably reduced chain mobility compared to polymer rubbers.…”

Physical aging of hydroxypropyl methylcellulose acetate succinate via enthalpy recovery

“…This relationship has been most often explored using equilibrium measurements on as-processed polymers and ASD systems subjected to isothermal annealing protocols (i.e., stability studies), high relative humidity, or added water content. [56][57][58][59][60][61] However, there remains a dearth of studies on the non-equilibrium physical aging behavior of pharmaceutical polymer systems, [62][63][64] with only one recent study by Lapuk et al on poly(vinylpyrrolidone). 65 This dearth represents the challenge of accurately investigating the implications of drug presence on the physical aging of the multicomponent ASD system, prompting a study on a pure polymer excipient system.…”