In vitro release and antibacterial activity of poly (oleic/linoleic acid dimer: sebacic acid)-gentamicin.

Aim: To investigate whether poly (oleic/linoleic acid dimer: sebacic acid)-getamicin [Poly(OAD/LOAD:SA)-gentamicin] delivery system was useful to treat chronic osteomyelitis.

Methods: Drug delivery system consisted of gentamicin sufate dispersed in a copolymer containing oleic/linoleic acid dimer (OAD/LOAD) and sebacic acid (SA) in a 1:1 weight ratio. The gentamicin release from [Poly(OAD/LOAD:SA)-gentamicin] was tested in water, 0.9 % saline, and phosphate buffer 0.1 mol/L.

Results: The gentamicin concentration peak was found on d 2, then slowly decreased, considerable amount of gentamicin was still released on d 50. From d 2 to d 50, the gentamicin concentration in the releasing fluids was from 59 to 42128-fold and 1.8 to 1314-fold of the MIC for Staphylococcus aureus and Escherichia coli, respectively. Staphylococcus aureus and Escherichia coli were strongly inhibited by the releasing fluids for 50 d. The gentamicin release and anti-bacterial activity in the three media were similar, only in 0.1 mol/L phosphate buffer, from d 2 to d 14 it was lower.

Conclusion: Poly(OAD/LOAD:SA)-gentamicin was useful to treat chronic osteomyelitis.