Evaluation of slipperiness of catheter surfaces.

A test method is described that allows the characterization of the subjective feeling of lubricity of catheter surfaces in a quantitative way. The test consists in pulling out, by a weight, a catheter tubing from a test tube filled with agar. Results show that the surface of a polyurethane catheter tubing coated with the hydrophilic poly (hydroxyethylmethacrylate) is readily hydrated by the water contained in the agar. The hydrogel coated tubing slides very quickly, due to the lubricating surface layer of water. The untreated polyurethane tubing and the same tubing after plasma treatment were definitely less slippery than the poly (hydroxyethylmethacrylate) coated ones. Atomic force microscopy was used to evaluate the contribution of the surface morphology of the samples to the obtained results.