chemical solutions in the nature of pharmaceutical preparations to fill and flush medical devices, namely catheters, to maintain catheter patency, while inserted in the human body; chemical solutions as medical preparations that include as a main ingredient ethylenediamine tetra-acetic acid to help maintain catheter patency, during in-vivo use; sterile chemical solutions in the nature of pharmaceutical preparations that include as a main ingredient tetra-sodium ethylenediamine tetra-acetic acid to fill and flush medical devices, namely catheters, during in-vivo use; medical lubricant in the nature of a gel for inserting medical devices into the urethra; lubricating gel that includes ethylenediamine tetra-acetic acid as a main ingredient, for inserting medical devices into the urethra; lubricating gel that includes tetra sodium ethylenediamine tetra-acetic acid as a main ingredient for inserting urological catheters into the urethra; topical gel that includes ethylenediamine tetra-acetic acid as a main ingredient, applied to catheter insertion site for use as a lubricant to reduce friction and pain of insertion