a catheter tube having improved strength and lubricity . the catheter tube can be used advantageously as a guide wire tube for small profile intravascular catheters . the tube can be formed by extruding a mixture of thermoplastic polymeric material , hard particles , lubricating particles , and a lubricant . the lubricant is preferably an external lubricant capable of forming a film over the tube surfaces . one tube is formed of polyamide , molybdenum disulfide particles , ptfe particles , and zinc stearate . applicants believe the hard disulfide particles and lubricating ptfe particles protrude from the tubular surfaces and are coated with a film of lubricating zinc stearate . the film is believed to reduce the friction and resulting ptfe elongation caused by a guide wire sliding over the ptfe protrusions .