GB2096466A

GB2096466A - Contraceptive device

Info

Publication number: GB2096466A
Application number: GB8209678A
Authority: GB
Original assignee: Caligen Foam Ltd
Current assignee: Caligen Foam Ltd
Priority date: 1981-04-10
Filing date: 1982-04-01
Publication date: 1982-10-20

Abstract

A contraceptive device comprises a generally spherical element formed from an absorbent resilient material and impregnated with a spermicide. The spherical element or ball is preferably formed from a foamed plastics material such as polyurethane foam. Impregnation is preferably effected when the foam is in sheet or slab form following which the sheet or slab is formed into spherical elements of the desired size.

Description

SPECIFICATION Contraceptive devices The invention relates to contraceptive devices.

It is an object of the invention to provide a contraceptive device which is safe and can be widely and easily used and readily and cheaply manufactured.

According to the invention a contraceptive device comprises a generally spherical element formed from an absorbent resilient material and impregnated with a spermicide.

The spherical element or ball is preferably formed from a foamed plastics material such as polyurethane foam of the open-celled type to allow impregnation of the spermicide. The foam may or may not be reticulated.

The size of the ball is such that in an uncompressed state it exceeds the diametral size of the female vagina so asto be in a compressed state when in use. The ball is preferably between 1" and 6" in diameter. The density of the foam may be varied within wide limits but is preferably between 10kg/m3 and 60kg/m3. The preferred foam is a polyetherurethane foam of density 17kglm3 and diameter 14 inches in which the uptake of spermicide is in the range 0.9-290 wt %.

Any suitable spermicide which can readily spread throughout the internal and external cell structure of the foam may be utilised. The spermicide should be selected so that it will remain in place and active for the desired period, for example up to 72 hours. An example of a suitable spermicide is nonyl phenol ethoxylate which is typically applied in an amount of 0.05-ig per ball.

Impregnation of the spermicide into the ball will generally be effected by mechanical means on a mass production basis so that the contraceptive device will be supplied already impregnated. Alternatively impregnation could be carried out by users prior to use, thereby making the product washable and reusable.

It is preferred that impregnation be effected when the foam is in sheet or slab form, following which the sheet or slab is formed into spherical elements of the desired size.

Thus the invention also provides a method of producing contraceptive devices comprising providing a sheet or slab of absorbent resilient material, impregnating the material with a spermicide and producing a plurality of individual spherical elements from the impregnated sheet.

Preferably impregnation of the sheet is effected by applying the spermicide to the sheet while the sheet is in a compressed state and subsequently allowing the sheet to expand, for example using the apparatus shown in co-pending application No.

8106769.

Preferably the sheet comprises an open-celled foamed plastics material such as polyurethane foam.

The spermicide may be impregnated either in pure form or as a solution in a suitable solvent.

The following examples illustrate specific embodiments of the invention but are by way of example only and are not intended to be limitative.

Example 1 A sheet of flexible polyether-urethanefoam having a density of 17kg/m3, cell count of 15 cells per linear cm. and thickness of 45mum was impregnated with nonyl phenol ethoxylate at room temperature using the apparatus described in co-pending Application No. 8106769 using a nip gap of 1 m/m to yield a nonyl phenol ethoxylate uptake of 900g/m2. The finished foam sheet was then cut into strips of 45mum cross section which were fed into a foam shaping machine to yield sphernsofdiameter4Om/rn. These had a weight of 1.859 and a spermicide uptake of 1 .0g (approximately 118 wt%).

Example 2 A sheet of felxible polyether-urethane foam having a density of 30kglm3, cell size of 20 cells per linear cm. and thickness 50mum was impregnated in a similar mannner to Example 1 but with the nip gap set at 15mum The uptake of nonyl phenol ethoxylate was controlled via the machine speed at 228 g/m2.

This foam sheet was then cut into strips of 50mom cross-section which were subsequently shaped into 45m/m diameter foam balls having a weight of 2.29 and a spermicide uptake of 0.29 g (i.e. 15.2 wt%).

Example 3 This was a repeat of Example 2 except that the foam was a flexible polyester-urethane of density 30kg/m3 having 22 cells/linear cm.

The resultant devices are inserted either by manual force or by prepacking into a tube. In both cases this allows the ball to be inserted in a compressed form. After insertion the ball will expand towards its normal shape thus filling the vaginal space in proximity to the cervix. When in position the ball will still be in a compressed state having a lower volume than that when it is fully expanded without external pressure. When in position the ball prevents sperm from reaching and fertilizing the female egg by providing both a mechanical and chemical barrier. If desired the ball may be provided with a suitable attachment to facilitate easy removal. The devices according to the Examples remained active for up to 72 hours.

While it is possible to impregnate the ball after fabrication, impregnation of foam in sheet or slab form priorto conversion into balls or spheres has been found to result in more uniform impregnation of the spermicide and lends itself more readily to mass production as sheets or slabs are more readily handled and controlled than preformed spheres.

Dependent on the density and diameter of the ball the uptake of spermicide can range from 0.1 to 500% byweight based on initial foam weight Various modifications may be made without departing from the invention. For example the overall size, the cell size and the density of the foam may be varied to meet different requirements and a variety of different spermicides may be utilised. While reference has been made to the use of foamed plastics materials and especially polyurethane foam other absorbent resilient materials may also be used. Moreover while it is envisaged that the device will generally be of spherical form it may in some instances deviate from a true sphere so as to be of oval orsimilarshape.

Claims

1. A contraceptive device comprising a generally spherical element formed from an absorbent resilient material and impregnated with a spermicide.

2. A contraceptive device according to claim 1 wherein said absorbent resilient material is an opencelled foamed plastics material.

3. A contraceptive device according to claim 2 wherein said foamed plastics material is polyurethane foam.

4. A contraceptive device according to claim 3 wherein said polyurethane foam is a polyetherurethane foam.

5. A contraceptive device according to any of claims 2 to 4 wherein the density of the foam is between 10kg/m3 and 60kg/m3.

6. A contraceptive device according to any of claims 2 to 4 wherein the density of the foam is between 15kg/m3 and40kg/m3.

7. A contraceptive device according to any of claims 2 to 6 wherein the foam has 15-20 cells per linear centimetre.

8. A contraceptive device according to any preceding claim having a diameter of 16 inches.

9. A contraceptive device according to any preceding claim wherein the uptake of spermicide is in the range 0.9-290% by weight of the resilient material.

10. A contraceptive device according to any of claims 1 to 8 wherein the spermicide is applied in an amount of 0.05-19 per device.

11. A contraceptive device according to any preceding claim wherein the spermicide is nonyl phenol ethoxylate.

12. A contraceptive device comprising a generally spherical element having a diameter of 14 inches and formed from open-celled polyetherurethane foam having a density of 10-60kg/m3 and 15-20 cells per linear centimetre substantially uniformly impregnated with a spermicide in an amount of 0.9-290% by weight of the foam.

13. A contraceptive device substantially in accordance with any one of the foregoing Examples.

14. A method of producing contraceptive devices comprising providing a sheet or slab of absorbent resilient material, impregnating the material with a spermicide and producing a plurality of individual spherical elements from the impregnated sheet.

15. A method according to claim 14 wherein impregnation of the sheet is effected by appplying the spermicide to the sheet while the sheet is in a compressed state and subsequently allowing the sheet to expand.

16. A method according to claim 14 or 15 wherein the spermicide is impregnated in pure form.

17. A method according to claim 14 or 15 wherein the spermicide is impregnated as a solution in a solvent.

18. A method of producing contraceptive devices substantially as hereinbefore described.

19. A contraceptive device according to any of claims 1 to 12 produced by the method according to any of claims 14 to 18.