Coated condom

Abstract

A condom comprises, on one or more surfaces thereof, a self-lubricating coating comprising a dry powder having a particle size of 300 microns or less. The self-lubricating coating becomes lubricious when the coating comes into contact with a liquid environment. A method of making a self-lubricating condom comprises providing a dry condom and coating said condom, on one or more surfaces thereof, with a self-lubricating coating comprising a dry powder. The invention also provides the use of a dry powder such as xanthan gum to provide a self-lubricating coating for a condom.

Claims

1. A dry condom comprising: an interior surface of the dry condom; an exterior surface of the dry condom; and a dry self-lubricating coating on at least a portion of one or both of the interior and exterior surfaces of the dry condom, the dry self-lubricating coating consisting of a dry powder having a particle size of between 75 to 300 microns; wherein the dry self-lubricating coating is present in a dry state on one or both of the interior and exterior surfaces of the dry condom and is substantially non-lubricious in that state; wherein the dry self-lubricating coating becomes lubricious when in contact with a liquid environment, and wherein the dry powder consists of xanthan gum.

2. The dry condom according to claim 1, wherein the dry condom comprises one or more enhancement actives.

3. The dry condom according to claim 2, wherein one of the one or more enhancement actives is in powder form.

4. The dry condom according to claim 2, wherein one of the one or more enhancement actives is a performance enhancing active.

5. The dry condom according to claim 2, wherein one of the one or more enhancement actives is a sensory effect active.

6. The dry condom according to claim 2, wherein one of the one or more enhancement actives is a flavour enhancing active.

7. The dry condom according to claim 2, wherein one of the one or more enhancement actives is a desensitising agent.

8. The dry condom according to claim 2, wherein one of the one or more enhancement actives is a vasodilator.

9. A package comprising the dry condom according to claim 1.

10. The package according to claim 9, wherein the package comprises foil.

11. The package according to claim 9, wherein the package is free of any lubricant in a liquid or gel-like state.

12. The package according to claim 9 further comprising a liquid or gel like lubricant.

13. The dry condom according to claim 1, wherein the liquid environment is aqueous or aqueous-based.

14. The dry condom according to claim 1, wherein the dry powder is water-soluble.

15. The dry condom according to claim 1, wherein the dry powder has a particle size of 200 microns or less.

16. The dry condom according to claim 1, wherein the dry powder has a particle size of 100 microns or less.

17. The dry condom according to claim 1, wherein the condom is free of lubricant.

18. The dry condom according to claim 1, wherein the condom is free of oil-based or water-based lubricants.

19. The dry condom according to claim 1, wherein the weight of the dry self-lubricating coating is from 0.005 g to 0.5 g per condom.

20. A method of making a dry self-lubricating condom comprising the steps of: providing a dry condom having an interior surface and an exterior surface; and coating a dry self-lubricating coating on at least a portion of one or both of the interior and exterior surfaces of the dry condom, the dry self-lubricating coating consisting of a dry powder having a particle size of between 75 to 300 microns, wherein the dry self-lubricating coating is present in a dry state on one or both of the interior and exterior surfaces of the dry condom and is substantially non-lubricious in that state, and wherein the dry powder consists of xanthan gum.

21. The method according to claim 20, wherein the coating step comprises tumbling the dry condom with the dry self-lubricating coating.

22. The method according to claim 21, wherein the tumbling is dry tumbling.

23. The method according to claim 21, wherein the tumbling is carried out for from 15 to 45 minutes.

24. The method according to claim 20, wherein the coating step further comprises a step selected from the group consisting of electrostatic spraying and powder flocking.

25. The method according to claim 20 further comprising using from 5 g to 500 g of dry powder per 1000 condoms.

26. A dry condom comprising: an interior surface of the dry condom; an exterior surface of the dry condom; and a dry self-lubricating coating on at least a portion of one or both of the interior and exterior surfaces of the dry condom, the dry self-lubricating coating consisting of a dry powder having a particle size of between 75 to 300 microns, wherein the dry self-lubricating coating is in a substantially non-lubricious state, wherein the dry self-lubricating coating is configured to transition to a substantially lubricious state when in contact with a liquid environment, and wherein the dry powder consists of xanthan gum.

Description

(1) The present invention thus encompasses the use of a dry powder which is non-messy or non-sticky and can be applied to the condom during processing. The condom then becomes lubricious in contact with aqueous environments such as vaginal fluids during coitus, thus providing lubrication. That is, the dry power, which when dry does not provide any significant degree of slip or lubriciousness, becomes lubricious when wet. The main advantage of this feature is that the end user does not experience a sticky or messy condom when opening the foil and donning the condom.

(2) FIG. 1 shows a process flowchart illustrating one embodiment of the present invention.

(3) Any suitable condom may be used as the basic condom component of the present invention, provided that the object of achieving a lubricious coating can be attained. We have found that a variety of different kinds of condom, whether natural or synthetic, may be used as desired.

(4) As will be clear to those skilled in this field, condoms may be manufactured from a variety of materials including natural substances such as natural rubber latex, or synthetic materials. For example, synthetic materials include carboxylated rubbers, such as carboxylated styrene-butadiene rubber and carboxylated acrylonitrile-butadiene rubber; nitrile rubbers, such as nitrile-butadiene rubber; polyurethane, and synthetic polyisoprene. These materials may be used either individually, or two or more may be blended depending upon the characteristics required. Useful blends include those where natural rubber latex is blended with one or more synthetic materialsfor example, a blend of natural rubber and polyurethane. Preferably, a condom made from natural rubber latex, or comprising a natural rubber latex base, is used.

(5) The condom itself may be manufactured in any suitable way. Typically, this is done by dipping a condom-shaped former into a latex or latex blend to form a film which is subsequently dried and cured. It will be understood that the manufacture of suitable rubber latexes, and the subsequent formation of condoms therefrom, are well understood procedures to those skilled in this particular art.

(6) The finished condom sheath is then coated with a self-lubricating coating as described further below. In use, the coating on the condom surface (preferably on both the inner and outer surfaces) will come into contact with a liquid, preferably aqueous, environment, such as provided by vaginal secretions or saliva, or other synthetic liquid or aqueous products. The coating then becomes lubricious in response to this contact, and this provides lubrication, or additional lubrication, during coitus. Lubricity is a well known characteristic in this particular field, and essentially relates to the amount of slip provided by a surface or coating. A lubricious surface or coating will have a low coefficient of friction (for example, compared to an uncoated and otherwise untreated elastomeric film surface), and generally demonstrate stringy and mucous-like behaviour.

(7) Any suitable dry powder may be used to form the self-lubricating coating, provided that the powder is biocompatible with mucous membranes and does not damage condoms during tumbling or subsequent processing and storage.

(8) A preferred powder comprises xanthan gum. Xanthan gum is a high molecular weight polysaccharide gum, containing D-glucose and D-mannose as the dominant hexose units, along with D-glucuronic acid. It is normally prepared as the sodium, postassium, or calcium salt, and typically has a molecular weight of around 210.sup.6. It is generally produced by aerobic fermentation of a carbohydrate source using, for example, Xanthamonas campestris. Any suitable type of xanthan gum may be used, and suitably the gum is provided in particulate (i.e. powder) form. Transparent (i.e. clear) xanthan gum is a preferred kind, suitably transparent, particulate xanthan gum. Desirably, the xanthan gum is soluble in hot water and cold water. Suitable gums include those available from CP Kelco (headquatered in Atlanta, Ga., USA). A preferred type are those available under the tradename Keltrol, with the Keltrol cosmetic grade (CG) products being particularly preferred. These are high quality powders with a low bacterial count. Examples of suitable powders include Keltrol cosmetic grade-T (CG-T), which is a transparent powder; and Keltrol cosmetic grade-F (CG-F) which is a fine powder product.

(9) Other suitable xanthan gum products include those available from Bestessen Natural Ltd (Shandong, China). The Food Grade (FG) gums are preferred, and useful examples include Natraxan FG-HD, which is a quick dispersible gum, and Natraxan FG200 which is a fine powder product.

(10) Other suitable powders which may be used include those comprising polysaccharides, in particular high molecular weight polysaccharides and homopolysaccharides, for example homopolysaccharides of glucose. Polysaccharides and homopolysaccharides having a molecular weight of about 10 KDa or higher are preferred, including, for example, those having a molecular weight of about 50 KDa or above, or 100 KDa or above. Any suitable polysaccharide may be used, provided that the powder is biocompatible with mucous membranes and does not damage condoms during tumbling or subsequent processing and storage. A suitable example is pullulan, which is a linear homopolysaccharide polymer consisting of maltotriose units. Pullunan is produced from starch by the fungus Aureobasidium pullulans.

(11) Other suitable powders which may be used include those comprising polyacrylamide, a polymer formed from acrylamide subunits. An ionic polyacrylamide, for example an anionic polyacrylamide (for example those incorporating some acrylic acid), may be used if desired. Suitable examples include the polyacrylamide products available from Ciba Speciality Chemicals under the Magnafloc range. These are anionic polyacrylamides in the form of free-flowing granular powders. A suitable example includes the product Magnofloc LT 27 AG, which is a high-molecular weight anionic polyacrylamide. Again, any suitable polyacrylamide may be used, provided that the powder is biocompatible with mucous membranes and does not damage condoms during tumbling or subsequent processing and storage.

(12) Other suitable powders which may be used include those comprising carrageenan. Carrageenan is a cell wall hydrocolloid found in certain species of seaweeds belonging to red algae, and it can be extracted therefrom. A preferred type is carrageenan comprising sulphated polysaccharides and extracted from red seaweed. Suitable carrageenan products include those available from CP Kelco under the Genu range. A preferred type is Carrageenan CG-129. Again, any suitable carrageenan may be used, provided that the powder is biocompatible with mucous membranes and does not damage condoms during tumbling or subsequent processing and storage.

(13) Other suitable powders include those based on extracts from the Aloe vera plant, which extracts are collectively commonly known by the same name as the plant. Freeze dried Aloe vera in particulate form is preferred.

(14) Normal dusting powders such as corn starch, silica and carbonates are generally not suitable powders for producing a self-lubricating coating, because they are not readily soluble in aqueous environments so as to produce lubricious coatings.

(15) Preferably, if desired, the condom or the powder or the coating does not comprise poly(ethylene oxide); or glycerol; or polyethylene glycol; or squalene, its partial hydrolyzate or squalane.

(16) We prefer to use a powder having a small particle size, and typically the powder will have an average particle size of less than about 200 microns, preferably about 180 microns or less. Smaller particle sizes may also be used, for example about 100 microns or less. In particular, we have found xanthan gum powders, and polysaccharide powders, particularly high molecular weight polysaccharide powders, having a particle size of about 180 microns (or less) to give good results. For example, the particle size of Keltrol CG-T and Ketrol CG-F are approximately 180 microns and 75 microns respectively. Powders with a particle size of about 180 microns or less have been found to provide high lubricity on condoms, and such condoms also meet the criteria set out in ISO 4074:2002 and ISO 23409:2011 with respect to initial and pre-determined ageing conditions through out product's shelf life.

(17) A preferred process according to the present invention is shown schematically in FIG. 1. A condom is produced by dipping a condom-shaped former or mandrel into a latex or latex blend to form a thin film which is subsequently dried and, if desired, cured or vulcanised with heat or chemical treatments. Typically, the process includes a washing step in which the condom is washed in a slurry of aqueous carbonate solution (e.g. aqueous calcium carbonate). Preferably, the film is then dried so as to remove all moisture. It is a particularly preferred feature of the invention that the condoms are completely dry before being subsequently coated.

(18) Once the finished condom sheaths have been manufactured, a quantity of these dry condoms is placed in a tumbler, and a quantity of coating or dry powder such as particulate xanthan gum is added. The condoms and powder are then tumbled together for a chosen periodtypically for 20 to 30 minutes. The process serves to coat the condom with the powder, and a certain quantity of the powder will adhere naturally to the inner and outer surfaces of the condoms so as to provide a substantially uniform coating on all surfaces.

(19) It is a preferred feature of the invention that the tumbling process is carried out in a dry environmentthat is, both the condoms and coating or powder are introduced in the dry state and the tumbler apparatus itself does not introduce any moisture.

(20) The coated condoms may then be removed from the tumbler and tested for defects using standard quality control procedures. Typically, electronic testing (ET) and/or water testing are used to check for any defects (such as holes) in the condom film, and defective condoms discarded as required.

(21) The condoms may then be packaged (i.e. foiled) in the usual way.

(22) The coating may be applied to the condom sheath using any suitable technique, but a preferred method is the tumbling process. Other methods of coating the condom include, but are not limited to, electrostatic spraying, powder flocking or any other application method used to coat dry powder on the condom surface.

(23) Generally, the tumbling method is a process that applies a coating or coating composition in a liquid or solid state onto an elastomeric surface such as a condom by placing the condoms into a tumbler apparatus and then introducing into the tumbler either the liquid composition coating or a solid coating composition such as a powder. In the present invention, the coating is introduced in the dry, solid state, preferably as a powder. The condoms are then tumbled with the coating for a desired period of time.

(24) In a preferred aspect, the condoms are tumbled with the chosen powder only, without the addition of, or need for, other carriers or components. However, more than one dry powder may be used if desired, although generally a single powder is employed.

(25) The tumbler apparatus may comprise any suitable design, but will generally comprise a large circular drum which may be rotated about a central axis at a chosed revolution speed. As will be understood, the speed of revolution of the drum (in rpm) and the temperature of the tumbling may be selected as desired by the operator, depending upon the type of powder being used. We typically prefer to tumble the condoms for one cycle of about 30 minutes at ambient temperature (for example 20-25 C.), although any suitable conditions may be used. Preferably, the tumbling conditions are chosen so as to produce a substantially uniform coating on both the inside and outside surfaces of the condom.

(26) In a preferred aspect of the process, from about 5 g to about 500 g of powder (for example, xanthan gum) is used per 1000 dry condoms, typically 50 g to about 500 g. However a desired amount is in the range 100-500 g per 1000 dry condoms. The condoms are tumble dried with the dry powder (such as xanthan gum) in a conventional tumbling apparatus. Any suitable tumbling time may be used, such as from 15 to 45 minutes, but typically a period of about 30 minutes is suitable. Preferably, the process is carried out at ambient temperaturefor example from 20-25 C.

(27) For example, 9600 condoms that have passed QC inspection are placed inside the tumble drum (illustrated in FIG. 2). 4800 g of xanthan gum is then placed inside the tumble drum and tumbled for about 30 minutes at ambient temperature.

(28) The condoms are thus coated with the powder. We have found that an optimum level of coating, particularly with xanthan gum, can be obtained whilst using about 300 g of powder per 1000 condoms, although it will be appreciated that this will vary depending upon the type of condom and powder used.

(29) After this period the tumbling is stopped and sufficient powder has been attached to the inner and outer side of the condom. The condom is essentially dry and can be processed through electronic testing and foiling as is standard practice for those skilled in the art.

(30) Preferably, no additional lubricant is added to the foil package containing the condom. Generally, additional lubrication of this kind will not be necessary for the condoms of the invention. However, it is envisaged that package may further includes a liquid or gel like lubricant.

(31) It is further envisaged that one or more enhancement actives may be added to or be present in the coating. Enhancement actives are preferably in powder form, although it is also envisaged that they may be gels and/or liquids. Enhancement actives preferably include one or more of a performance enhancing active such as a desensitising agent or vasodilator (for example benzocaine retardant cream or glyceryl trinitrate), a sensory effect active (that provides a sensation feeling of cooling, tingling or warming), or a flavour enhancing active

(32) The following example illustrates the present invention.

EXAMPLE

(33) Four different types of xanthan gum were selected for testing, They are Keltrol CG-T and CG-F and the FD-HD and FG200 products available from Bestessen Natural Ltd. These powders were tested under various tumbling conditions; Either 200 g or 500 g of powder was used per 1000 condoms, and the tumbling time was varied between 10 and 30 minutes. For each test, 1000 dry condoms were tumble dried with either 200 g or 500 g of the selected powder for up to 30 min in a conventional tumbling apparatus. Batches of 30 condoms were removed at intervals of 10, 20 and 30 minutes.

(34) The amount of powder adhered to the condoms after tumbling for the selected time period was measured. On average, an amount of powder ranging between about 0.09 g and 0.22 g was deposited per condom. It is particularly preferred to be in the range 0.01 g and 0.12 g.

(35) Each batch was further tested in order to determine the integrity of the condom film, in particular to check for damage to the film such as small holes. Both standard electrical testing (ET) and water testing were carried out according to conventional techniques, and the results are shown in Table 3.

(36) The ET and Water Tests are conducted in accordance with Annex L of ISO 4074:2002. Brief details of the tests are given below.

(37) Water Test: filling of the condom with water 300+/10 cm.sup.3 at a temperature between 10 and 40 C. Inspect the condom for visible signs of leakage. A failure is deemed to be any condom exhibiting visible signs of leakage from holes more than 24 mm+/1 mm from the open end of the condom. In the absence of any leakage the condom is then rolled (at least one revolution) on coloured absorbent paper.

(38) Electrical Test (ET): Fit the open end of the condom on to the mount of the Electrical Tester. Add 200+/10 ml electrolyte (consisting of an aqueous sodium chloride solution), and inspect for visible electrolyte leakage. Deem as failed any condom which exhibits visible leakage. Submerge the non-leaking condom in a container also containing electrolyte (at least 25 mm from open end of condom is submerged). Apply 10V stabilized continous voltage source in series with 10 kohm high precision electrical resistance between the electrode in the container and the electrode inside the condom. Measure the voltage at the resistor after 10+/2 secs.

(39) If a voltage equal to or greater than 50 Mv, empty the condom and subject the condom to Water Test.