Deep eutectic solvents as simultaneous plasticizing and crosslinking agents for starch.

The aim of this work was to prepare deep eutectic solvents (DES) made with choline salts with α-hydroxylate anions and glycerol and apply them as starch plasticizers. Additionally, crosslinking potential of polyfunctional anions from the salts was investigated. Starch/DES premixtures were rheologically and thermally (DSC, TGA) analyzed. Thermoplastic starch (TPS)/DES films were prepared via thermocompression molding. Influence of choline salt to glycerol molar ratio, type of anion and compression parameters on mechanical, dynamic mechanical, thermal and sorption properties as well as structural morphology (XRD, FTIR analysis) was studied. DES containing citrate anion exhibited parallel crosslinking and plasticizing ability of polysaccharide matrix as applied techniques confirmed. The higher choline citrate (CCit) content in DES the higher tensile strength, more amorphous structure and lower sorption degree to CCit:G 1:6 M ratio. XRD revealed that TPS/CCit-based DES films did not retrograde even after one year of storage. The best compression parameters for studied systems were: 140 °C, 12 tons, 10 min.

Poly(isosorbide succinate)-based in situ forming implants as potential systems for local drug delivery: Preliminary studies.

In situ forming implants (ISFI) are proved to be effective drug delivery systems in various local therapies. This research focuses on preliminary characteristics of a new biodegradable ISFI formulation based on poly(isosorbide succinate) (PISU) for modulated, over 3-week, release of doxycycline hyclate (DOXY). The Alamar Blue cytotoxicity assay was carried out for PISU using FK-1 and AoSMC cell lines. PISU resin was found to be non-toxic in wide range of concentrations. The formulation viscosity, dependent on shear rate, facilitates its easy injection into required site where solid depot is formed immediately after injection. DOXY, incorporated into this formulation, was released in vitro within 21 days, during which collected solutions exhibited antibacterial activity against gram-positive and gram-negative bacteria Staphylococcus aureus and Escherichia coli, respectively. The morphology of the precipitated depots was characterized by scanning electron microscopy (SEM). The obtained results suggest potential applicability of this new PISU-based formulation as injectable drug delivery system forming implant at an injection site by phase separation and precipitation of the polymer.