germicidal properties are provided for colloidal lubricating gels without destruction of the physical properties of the colloidal gel by the incorporation therein of an iodophor within strict limits as to the quantities and relative quantities of the iodophor - former , the iodine and the gel - forming colloid . these germicidal colloidal lubricating gels remain stable and retain their germicidal effectiveness . as a result , these compositions can be used for the lubrication of catheters and other instruments to facilitate their insertion into a body cavity and because these compositions do not cause pain or irritation their use reduces the risk of infection and tissue - trauma .