[Drug release properties of sodium alginate hydrophobically modified by star polylactic acid].

Inorganic/polymer hybrid star polylactic acid (POSS-PLA) was obtained through ring-opening polymerization of lactide by using polyhydroxyl cage silsesquioxane (POSS-OH) as the core and tin (II) octoate as the catalyst. The star polylactic acid (POSS-PLA) was used to modify sodium alginate hydrophobically and a drug carrier was obtained. The drug release behavior was investigated by using ibuprofen as the model drug. The results showed that the drug loading rate could be improved and the release rate was postponed with an increase of POSS-PLA content in the carries. The release mechanism gradually changed from the first-order to the zero-order pattern after the modification.

(Z)-Methyl 3-(4-ethoxy-anilino)but-2-enoate.

The title compound, C(13)H(17)NO(3), was synthesized from methyl 3-oxobutanoate and 4-ethoxy-benzenamine using a catalytic amount of InBr(3) under solvent-free conditions. The 3-amino-but-2-enoic acid methyl ester group is planar and forms a dihedral angle of 83.4 (1)° with the benzene ring. The eth-oxy group is slightly twisted away from the benzene ring [dihedral angle = 13.8 (1)°]. An intra-molecular N-H⋯O hydrogen bond generating an S(6) ring is observed. Mol-ecules are linked into a chain along the b axis by inter-molecular C-H⋯O hydrogen bonding.

(Z)-3-[1-(4-Methoxy-anilino)ethyl-idene]-4,5-dihydro-furan-2(3H)-one.

In the title compound, C(13)H(15)NO(3), the dihydro-furan-one ring is planar to within 0.012 (4) Šand it forms a dihedral angle of 42.8 (2)° with the benzene ring. The amino-ethyl-idene group is coplanar with the dihydro-furan-one ring. The meth-oxy group is slightly twisted away from the benzene ring. An intra-molecular N-H⋯O hydrogen bond, generating an S(6) ring, is observed. In the crystal structure, the mol-ecules exist as C-H⋯O hydrogen-bonded dimers.