Thesis
Investigation of polyester films for the controlled release of cipeofloxacin
- Creator
- Rights statement
- Awarding institution
- University of Strathclyde
- Date of award
- 2012
- Thesis identifier
- T13445
- Qualification Level
- Qualification Name
- Department, School or Faculty
- Abstract
- Ureteral stents provide a surface for bacterial colonization and biofilm growth, which is detrimental to the clinical outcome. This problem may be solved by using controlled, localized delivery of ciprofloxacin, which is used in the treatment of urinary tract infections. To achieve this, we envisage the encapsulation of ciprofloxacin in polyester stent coatings (films). This thesis outlines four major topics: 1) synthesis of polyesters with varying crystallinity, 2) glass transition of poly-lactic-co-glycolic acid (PLGA) and poly-D-lactic acid (PDLA) films, 3) morphology and drug distribution in polyester (PLGA and PDLA) films of varying thickness, and 4) drug release from polyester films. With respect to these topics, we found that it was possible to use a novel microwave method for the de novo synthesis of PDLA , irradiating at 120 °C for 5 min without burning. However, traces of the lactide monomer remained on analysis and the scale-up of the procedure was abandoned. Using, commercially supplied PLGA, we successfully developed dip-coated and spin-coating methods to generate multi-layer polyester films on flat, glass surfaces. Characterisation of these films by differential scanning calorimetry (DSC) showed that the glass transition (Tg) decreased with an increase in the thickness of polyester layers. The presence of entrapped drug (ciprofloxacin) did not influence the Tg. The morphology and chemical composition of the films was characterised by Optical microscopy. Morphology was mainly influenced by the presence of the crystalline ciprofloxacin during spin-coating, and Raman signal strength was dependent on the film thickness. In vitro release of ciprofloxacin from the films showed a 'burst release' profile for single films harbouring drug, that was dependent on the hydrophilicity of the polyester and the degree of ciprofloxacin loaded and present on the film surface. Attenuation of the burst release was successfully accomplished by multi-layer film systems where a blank polyester layer was coated on top of the drug-loaded layer. In conclusion, we show that it is possible to maintain the chemical and physical integrity of ciprofloxacin and polyester during the coating process, and that the release of drug can be controlled by engineering multi-layer systems. Coating stents in a similar manner may therefore achieve the desired localized delivery of ciprofloxacin. Peer reviewed publication(s) based on the work described in this thesis: 1. Characterization of polyester films for the controlled release of ciprofloxacin; Lamprou, D., Ramayanapu, R., Urquhart, A., van der Walle, C F. 8th World Meeting on Pharmaceutics, Biopharmaceutics and Pharmaceutical Technology, 19-22 March, 2012, Istanbul.
- Resource Type
- DOI
- Date Created
- 2012
- Former identifier
- 991365
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