Simple strategy of the use of pharmaceutically functionalized ionic liquids in a new generation of polymer nanocarriers for the combined delivery of ionic p-aminosalicylate and ampicillin

Single and dual bioactive linear poly(ionic liquid)s (PIL) were synthesized for use as nanocarriers in drug delivery systems (DDS). These PILs were obtained through the (co)polymerization of the choline-based monomeric ionic liquids (MIL) with pharmaceutical anions possessing antibacterial properties, specifically [2-(methacryloyloxy)ethyl]trimethyl-ammonium with ampicillin and p-aminosalicylate (TMAMA/AMP and TMAMA/PAS). The copolymers exhibited varying chain lengths defined by a degree of polymerization (DP_n = 122–370), and differing contents of ionic fraction and drugs (TMAMA 61–92 %, AMP 61–93 % and PAS 16–21 %). These parameters were adjustable by the monomer conversion (33–92 %) and the initial ratio of comonomers. In aqueous solution, the polymer particles reached nanosizes, i.e. 190–328 nm for AMP systems and 200–235 nm for AMP/PAS systems. In the release process, the pharmaceutical anions were released through exchange by phosphate anions in PBS at pH 7.4 at 37 °C. Depending on the copolymer composition the release of AMP was attained in 72–100 % (11.1–19.5 µg/mL) within 26 h by the single drug systems, while the dual drug systems released 61–100 % of AMP (14.8–24.7 µg/mL) and 82–100 % of PAS (3.1–4.8 µg/mL) within 72 h. The effectiveness in the drug delivery of the designed TMAMA polymers seems to be promising for future applications in antibiotic therapy and the combined therapy.