Design, characterization and in vitro evaluation of novel amphiphilic block sunflower oil-based polyol nanocarrier as a potential delivery system: Raloxifene-hydrochloride as a model

- Biodegradable and biocompatible hyper-branched polyol was synthesized via thiol-ene click reactions at room temperature.
- Raloxifene hydrochloride was used as a hydrophobic drug model to test the potential of polyol as a drug delivery system carrier.
- Polyol could be prepared as a nanoparticle for the sustained delivery of raloxifene hydrochloride.
- Based on low cytotoxicity, polyol provides a bio-based source for the design new drug delivery systems.

Presently, modern pharmaceuticals, are almost exclusively derived from the arduous refining of petroleum whose supply is inherently unsustainable. In order to address this issue bio-based materials are increasingly being used for chemical synthesis, particularly in drug delivery systems. Biodegradable and biocompatible hyper-branched polyol (an alcohol containing three or more hydroxyl groups) was synthesized via a facile method through the ring-opening and thiol-ene click reactions at room temperature. Due to the bio-based content of the polyol backbone, the synthesized polyol had both excellent biodegradability and low cytotoxicity. Raloxifene hydrochloride, an oral selective estrogen receptor modulator, was used as a hydrophobic drug model to test the potential of polyol as a drug delivery system carrier. Polyol showed an amphiphilic character and could be prepared as a nanoparticle for the sustained delivery of raloxifene hydrochloride, a drug with poor bioavailability in aqueous solution. Raloxifene hydrochloride was readily encapsulated in the lipophilic core of polyol whose branched hydroxyls were on the external part of the prepared nanoparticles. The diameter of the nanoparticles was 94 ± 0.43 nm, their drug entrapment efficiency was 93 ± 0.5% and they showed a sustained release profile (17 ± 1.5% after 4 weeks). The 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay showed low toxicity towards human osteoblast MG-63 cells. Based on its good biodegradability and low cytotoxicity, polyol provides a bio-based source for the design new drug delivery systems.

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