Evaluation and characterisation of urinary catheter coating utilising Hansen solubility parameters and FEA analysis

• We modelled Hansen solubility parameters to optimise a functional coating system.
• FEA model was developed to illustrate the magnitude of deflection expected with the hydrophilic coating on the catheter.
• The polymers were dissolvent in varying times using Tea's diagrams.
• Optimum coating provides a 6.55 fold reduction in surface friction in comparison to the uncoated catheter.
• A maximum deflection of 0.06mm over the time period of 0.5 s was predicted via FEA.

This work investigated the Hansen solubility parameters required to optimise a functional polyurethane base coat as an attachment for a lubricious polyvinyl pyrrolidone coating for polyvinyl chloride urinary catheters. Solvents included benzyl alcohol, tetrahydrofuran, acetonitrile, and cyclohexanone and blends thereof. The viscosity of the polymer–solvent compositions was characterised using Redwood No.1 viscometer. The UV cured polymer–solvent blends were fully characterised using scanning electron microscopy, differential scanning calorimetry, and digital goniometry. A finite element analysis (FEA) model of the urethra during catheterisation was also developed to illustrate the magnitude of deflection expected with the hydrophilic coating on the catheter. Based on the theoretical modelling and subsequent experimental results this demonstrated that the materials dissolved in short succession of immersion in the calculated solvent blend. Also, the various compositions of polyvinyl pyrrolidone in the solutions produced noticeable variations in coating thicknesses ranging from 8 μm to 26 μm.

Tea's diagram for polymer–solvent system including the polymers PVP, PVC, and TPU, and the solvents benzyl alcohol, tetrahydrofuran, acetonitrile, and cyclohexanone.Figure optionsDownload high-quality image (115 K)Download as PowerPoint slide