The impact of storage conditions upon gentamicin coated antimicrobial implants

• Published in: Journal of pharmaceutical analysis Vol. 6; no. 6; pp. 374 - 381
• Main Authors: Mullins, Nicholas D., Deadman, Benjamin J., Moynihan, Humphrey A., McCarthy, Florence O., Lawrence, Simon E., Thompson, Jonathan, Maguire, Anita R.
• Format: Journal Article
• Language: English
• Published: China Elsevier B.V 01.12.2016; a Department of Chemistry, Analytical and Biological Chemistry Research Facility, Synthesis and Solid State Pharmaceutical Centre, University Col ege, Cork, Ireland%DePuy Synthes Ireland, Loughbeg, Ringaskiddy, Co., Cork, Ireland; Xi'an Jiaotong University
• Subjects: Coatings; Gentamicin; Gentamicin;Coatings;Storage; LC–ELSD; Original; stability; Storage stability testing; testing;LC–ELSD; Storage stability testing; Coatings; Gentamicin; LC–ELSD; LC-ELSD
• ISSN: 2095-1779; 2214-0883
• DOI: 10.1016/j.jpha.2016.05.002

A systematic approach was developed to investigate the stability of gentamicin sulfate (GS) and GS/poly (lacticco-glycolic acid) (PLGA) coatings on hydroxyapatite surfaces. The influence of environmental factors (light,humidity, oxidation and heat) upon degradation of the drug in the coatings was investigated using liquidchromatography with evaporative light scattering detection and mass spectrometry. GS coated rods were foundto be stable across the range of environments assessed, with only an oxidizing atmosphere resulting insignificant changes to the gentamicin composition. In contrast, rods coated with GS/PLGA were more sensitiveto storage conditions with compositional changes being detected after storage at 60 °C, 75% relative humidity orexposure to light. The effect of γ-irradiation on the coated rods was also investigated and found to have nosignificant effect. Finally, liquid chromatography–mass spectrometry analysis revealed that known gentaminesC1, C1a and C2 were the major degradants formed. Forced degradation of gentamicin coatings did not produceany unexpected degradants or impurities.