Diffusivity of Cucurbitacin B in water swollen polyethylene oxide-b-polycaprolactone matrices with different PCL/PEO weight ratios

作者：Razavilar Negin; Choi Phillip^*

来源：Computational Materials Science, 2016, 118: 97-102.

DOI：10.1016/j.commatsci.2016.03.014

• Cucurbitacin B
• PEO-b-PCL
• PCL/PEO ratio
• Diffusivity
• Molecular dynamics

We used isobaric-isothermal molecular dynamics simulation to study the diffusivity of a hydrophobic drug Cucurbitacin B (CuB) in polymer matrices made up of a single polyethylene oxide-b-polycaprolactone (PEO-b-PCL) chain and different numbers of water molecules at body temperature (310 K) and ambient pressure (1 bar). Four PEO-b-PCL models were used. Three of them had the same total molecular weight of 3750 g/mol but different PCL/PEO weight ratios at 0.5, 1 and 2. The remaining model had a total molecular weight of 5000 g/mol and a PCL/PEO weight ratio of 1. The data showed that self-diffusion coefficients of CuB decreased with increasing PCL/PEO weight ratio and was insensitive to the water concentration at fixed PCL/PEO weight ratios. The first observation was attributed to a high number of hydrogen bonds formed between the oxygen atoms on CuB and the activated hydrogen atoms on the PCL block as the PCL/PEO weight ratio increased. It was found that degree of swelling and effects of the mobility of the PEO and PCL blocks on the diffusivity of CuB were minor and were overshadowed by the PCL block-CuB hydrogen bonds.

• 出版日期2016-6-1