the following examples are given to further illustrate the present invention . the scope of the invention is not , however , meant to be limited to the specific details of the examples . in a suitable glass - reaction vessel fitted with a variable speed paddle agitator and a side - wall scraper is placed 150 ml . of distilled water and 6 . 9 gm . of hydroxypropylmethylcellulose is slowly added . the mixture is warmed , stirred , and when complete solution is achieved , the heat is removed but the temperature and stirring are maintained so that the solution is in a fluid state , and 60 gm . of propylene glycol is added . in another vessel containing 100 ml . of distilled water is added 4 . 5 gm . of povidone - iodine and the mixture stirred until dissolved . when complete solution has been achieved , 1 . 5 gm . of glycerin is added . the povidone - iodine solution is then carefully mixed with the colloidal solution of hydroxypropylmethylcellulose . should it be desired to buffer the lubricating gel , then the well known compatible buffer salts such as citric acid and dibasic sodium phosphate may be used in sufficient amounts which are well known to the art . these buffer salts are added to the aqueous solution of povidone - iodine and prior to its addition to the hydroxypropylmethylcellulose solution . the preferred ph range for the new gel is between ph 4 . 5 and ph 5 . 5 . should it be desired to include a surfactant agent to reduce the interfacial tension of the colloid gel , then any pharmaceutically acceptable surface active agent may be used in sufficient quantity to reduce the surface tension of the gel to below 35 dynes / cm 2 at 25 ° c . and generally requires from 0 . 05 % to 0 . 25 % by weight of the surface active agent to achieve this preferred surface tension . the volume of the new composition is brought to 300 ml , with distilled water and the whole allowed to set at room temperature . the resultant brown , transparent , homogenous colloid gel contains 0 . 15 % of available iodine and has a viscosity of about 40 , 000 cps with an accepted range of from not less than 30 , 000 cps and not more than 50 , 000 cps , when determined with the brookfield rvt viscometer at 25 ° c . the formed gel is then packaged into unit containers to obtain germicidal lubrication of catheters and devices intended to be inserted into body cavities . in a suitable reaction vessel fitted with a stirring device is placed 100 ml . of distilled water and 1 gm . of methylcellulose is added and the whole stirred until complete dispersion is achieved . when the dispersion is uniform , then 2 gm . of povidone are added and the mixture stirred until complete solution is achieved . to this composition is added 0 . 2 gm . of finely - divided iodine crystals , in small increments , with stirring to avoid elevated temperature . successive increments of iodine are added after the preceding portion has been dissolved . the colloid dispersion is stirred for at least one hour , or until it is determined that a carbon tetrachloride extract of a sample of the composition does not give a positive iodine test and the vapor pressure determined for the respective sample of the preparation is essentially zero . to this composition is now added 20 gm . of propylene glycol and 0 . 1 gm . of glycerin . a small quantity of about 0 . 1 % by weight of a suitable non - ionic surface active agent , such as nonylphenoxypoly ( ethylenecoxy ) ethanol , which is known in the trade as igepal , a compound marketed by the gaf corporation , chemical division of new york , n . y . which amount is sufficient to lower the surface tension of the composition to 28 dynes / cm 2 . the volume of the composition is now brought to 200 ml . with a solution containing 0 . 07 % of sodium dibasic phosphate and 0 . 035 % of citric acid . two drops of 5 % sodium hydroxide solution are added to adjust the ph of the composition of ph 5 . the resultant composition is a brown , transparent , homogenous colloid gel with a viscosity of 38 , 000 cps containing 0 . 2 % of available iodine in stable homogenous colloid dispersion . the formed gel is packaged into unit containers , each containing 10 gm . of the newly formed germicidal colloidal lubricating gel , which is now ready for use to lubricate catheters and instruments . when it is desired to use alginic acid as the colloid gelling agent to prepare the microbicidal lubricating gel , then from 2 % to 5 % of alginic acid is utilized . a preferred form of alginic acid is sodium alginate and a small quantity of calcium ions is added to stabilize the gel - forming properties of sodium alginate solutions so that a solid , firm gel results . such calcium salts as calcium gluconate , calcium tartrate , calcium citrate , calcium salicylate or any other salt capable of yield calcium ions may be used . magnesium ions also may be used to enhance the gelling properties of sodium alginate and such magnesium salts as are capable of yielding magnesium ions may be utilized for this purpose . optimal magnesium salts for this purpose are the double salt magnesium and choline salicylate , magnesium salicylate , magnesium sulfate and magnesium chloride . to prepare the new germicidal lubricating colloid gel with sodium alginate , approximately 0 . 1 gm . of calcium gluconate is dissolved in about 100 gm . of water , and to this is added 2 gm . of sodium alginate , and 0 . 5 gm . of propylene glycol . the mixture is stirred until a uniform disperson results , then 1 gm . povidoneiodine usp is added . the mixture is brought to volume of 200 ml . with water and the whole set aside until the gelling stage has been completed . the resultant gel is amber - colored and transparent , with a viscosity of 32 , 000 cps and contains 0 . 1 % available iodine . the new gel is stable for prolonged periods of time and possesses desirable antimicrobial properties against all classes of microorganisms . a particular advantage of the new alginic and colloid gel base is that it may be buffered to be within the acid range in contrast to conventional sodium alginate ointment bases , which are not stable below ph 4 . 5 and most often are formulated to be above ph 6 , a ph range incompatible with iodine . an alternate compound to alginic acid as a gelling agent is the propylene glycol ester of alginic acid and the glycerin ester of aglinic acid , both of which compounds are used in a sufficient quantity to yield a concentration of alginic acid of from 3 % to 5 % by weight of the finished product . when the propylene glycol ester of alginic acid or the calcium ester of alginic acid is used , it is not necessary to add propylene glycol or glycerin as a bodying agent . the remainder of the steps are the same and the resulting product possesses the same properties as described for the products obtained as a result of examples 1 and 2 above . in place of the hydroxypropylmethylcellulose and the carboxymethylcellulose described in examples 1 through 3 above , there may be added suitable cellulose derivatives , as for example , hydroxymethylcellulose , hydroxyethylcellulose , hydroxypropylcellulose and carboxymethylcellulose which name is also used for its sodium salt , sodiumcarboxymethylcellulose . the range in concentration of the respective cellulose derivative selected is not less than 0 . 5 % and not more than 7 . 5 % by weight of the toral weight of the composition being prepared . mixtures of the cellulose derivatives may be used but the total concentration range as described above remains the same . the formed germicidal lubricating colloid gels prepared with the respective cellulose derivatives possess the same physiologic and germicidal properties described above and the essential differences amoung the respective formed gels in the resultant viscosity of the finished gel . thus , it may be desirable to use a cellulose derivative forming a more viscous colloid gel in southern geographic regions wherein the temperature is necessarily higher than that of the northern regions . care should be taken when the upper limit of concentration of the cellulose substance is used in a particular product formulation in that the temperature during manufacture is not elevated about room temperature , since heat will tend to coagulate the more concentrated , viscous colloid gel dispersions in the presence of iodine . when the germicidal lubricating gels prepared as described above were stood for prolonged periods , there were no stratification or separation into layers and also , the integrity of the available iodine content was maintained , thus insuring the germicidal antimicrobial activity of the preparation . furthermore , the iodine content was complexed in a form that it could not be extracted by carbon tetrachloride and the vapor pressure of the product was essentially zero to establish the combined complexed state of the new compositions . in place of the pevidone - iodine used in examples 1 , 3 and 4 above , there may be added a surfactant iodophor compound such as nonylphenoxypoly -( ethyleneoxy ) ethanol iodine complex , or polyoxypropylene poly -( oxypropylene )- polyoxyethylene copolymers , which are known by the generic name , iolyxamers , and which are marketed by wyandotte chemical corporation of midlands , mich ., in the range of concentration from 0 . 3 parts by weight to 4 parts by weight of the surfactant iodopher compound for each part of carbohydrate polymer used to prepare the gel . the critical determirant for the overall ratio of the amount of surfactant iodopher compound used is the concentration of iodine complexed to the respective carrier moiety . the concentration of iodine in these iodopher preparations may be as high as 40 % and as low as 0 . 1 % by weight . when the surfactant iodophor compounds are used to prepare the new germicidal lubricating colloid gel , then the use of a surface active agent to enhance the spreading qualities of the formed lubricating gel is not necessary since the surface tension of the formed composition will be below 30 dynes / cm 2 . the order of mixing of the respective compounds remains the same as described above . the resultant formed lubricating gels have a viscosity of between 30 , 000 cps and 50 , 000 cps and are stable for prolonged storage periods , retaining their advantageous broad spectrum antimicrobial properties . in place of the alginic acid , and / or the propylene glycol esters of alginic acid , and / or the glycerin ester of alginic acid as the gelling agent described in example 3 , there may be substituted an equivalent part by weight or tragacanth and / or gum karaya as colloidal gelling agents . however , when such substances are used as gelling agents it may be found desirable to add a gelling accelerator of from 0 . 1 part to 0 . 3 parts by weight of such cellulose - gelling agents as described in examples 1 , 2 and 4 above . the remainder of the manufacturing steps are the same , and the resulting germicidal lubricating colloid gels possess the same advantageous properties as the preparations described above . when it is desired to utilize the new formed germicidal lubricating colloid gel to facilitate the insertion of a catheter and / or instrument into the urethra , then the following procedure is utilized . ( a ) the patient is surgically prepared and the anogenital area is aseptically cleansed with a germicidal soap ; the surrounding skin areas cleansed with a suitable topical germicide and the area draped . ( b ) the sterile device is then coated with the newly formed germicidal lubricating colloid gel and carefully introduced into the urethra into the bladder . since trauma contributes to the development of infection , the appropriate catheter size should be used and the catheter and / or instrument should not be forced if any resistance is encountered . the balloon catheter is the preferred retention catheter with the balloon inflated to hold the catheter in the bladder . ( c ) after the insertion of the retention catheter , an antiseptic germicidal ointment is placed around the catheter to help minimize infection by the catheter conduit route . ( d ) a closed sterile drainage system is imperative and urine cultures with colony counts should be obtained periodically . the urine container should be lower than the catheter and the drainage system supplied with a valve to prevent the reflux flow of urine . at least , a daily change of container is imperative and this should be done more often if contamination is evident . it is important that the prophylactic use of systemic antibiotics be avoided , unless these are specially required , since relatively innocuous organisms have shown to be replaced by virulent pathogens . indwelling catheters must be changed at least every 7 to 10 days . when the above procedure is conducted with the newly formed germicidal lubricating colloid gel , the incidence of posttreatment infection is virtually eliminated , and the procedure is essentially without tissue trauma in contrast to the known injuries experiences reported after similar procedures , using older lubricating gels . while the invention has been illustrated with respect to particular compositions , it is apparent that variations and modifications can be made .
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 .