Synchronising of animal oestrus and intra vaginal devices useful therein

• US 20020058926A1
• Filed: 10/11/2001
• Published: 05/16/2002
• Est. Priority Date: 05/01/1996
• Status: Active Grant

• Current Assignee: Interag
• Original Assignee: Interag
• Inventors: Rathbone, Michael John, Burggraaf, Shane, Bunt, Craig Robert
• Granted Patent: US 6,663,608 B2
• Time in Patent Office: Days
• US Class Current: 604/514
• CPC Class Codes: A61D 7/00 Devices or methods for introducing solid, liquid, or gaseous remedies or other materials into or onto the bodies of animals for reproduction or fertilisation A61D19/00 ; devices for implanting pellets, radon seeds or the like A61M37/0069
• CPC Class Codes: A61K 31/57 substituted in position 17 beta by a chain of two carbon atoms, e.g. pregnane or progesterone
• CPC Class Codes: A61K 9/0036 Devices retained in the vagina or cervix for a prolonged period, e.g. intravaginal rings, medicated tampons, medicated diaphragms

Abstract

An intra vaginal device which is of a variable geometry and which includes a silicone matrix impregnated with progesterone, the confirmation and content of the progesterone impregnated matrix being such as to optimize effectiveness with a lower initial loading of progesterone.

Claims

1. An intra vaginal device of a variable geometry kind capable of being applied into the vaginal cavity of an animal selected from the group consisting of cattle, sheep, deer and goats, retainable therein over a period of time within the range of from 7 to 12 days and then to be withdrawable therefrom to allow the onset of oestrus, said device being characterised in that

a matrix of a cured silicone rubber material that includes greater than 5% by weight progesterone to the weight of the matrix defines an exterior surface (which may be all or part only of the device) of at least 75 cm² contactable once inserted in the vagina of such an animal by the vaginal membrane and/or vaginal fluid(s) of the animal,

the matrix of progesterone containing silicone rubber material has been formed by injection of the uncured progesterone containing matrix as a liquid into a mould for a sufficient time to achieve at a mould temperature or temperatures within the range of from 100°

C. to 210°

C. and a shape retaining at least partial cure thereof,

the total progesterone load (irrespective of whether alpha or beta progesterone or mixtures thereof) being from 1 to 1.5 grams within said matrix,

said surface area is available to at least substantially all of the matrix for progesterone release over a thickness of no greater than about 1 millimeter, and

said device upon vaginal insertion into such an animal is able to achieve and then maintain in the animal for at least seven days a minimum progesterone blood plasma level of 2 nanograms per milliliter of plasma of the animal and which after seven days from insertion will have a residual load in the silicone rubber matrix of less than 65% by weight of its progesterone load at insertion.

2. A device of claim 1 wherein said exterior surface is from 100 to 1500 cm².

3. A device of claim 1 or 2 wherein said matrix has about 10% by weight progesterone to the weight of matrix.

4. A device of any one of the preceding claims wherein said matrix at least in part encases a deformable frame.

5. A device of claim 4 wherein said frame is resilient.

6. A device of claim 5 wherein said frame is substantially in the form of a “

T”

with the arms of the “

T”

being deformable to allow introduction into the vagina of an animal, the “

T”

form being defined by a resilient spine about which (at least in part) there is moulded said matrix.

7. A device of any one of claims 4 to 6 wherein said frame is of nylon.

9. A device of any one of the preceding claims substantially as hereinbefore defined with reference to any one or more of the accompanying drawings.

11. A method of claim 10 wherein said device is as claimed in any one of claims 1 to 9.

14. In a method of attempting to synchronise the onset of oestrus of a herd of cattle beasts, the procedure of

administering intra vaginally to each animal of the herd progesterone from an intra vaginal device as claimed in any one of claims 1 to 9 and

after and appropriate period of time removing such devices to allow the onset of oestrus (the procedure optionally including the steps of administration of oestradiol and/or prostaglandin etc. as known in the art or otherwise), said method being further characterised in that level of progesterone in the blood plasma of each animal is at least 2 nanograms per milliliter until such time as the devices are withdrawn.

15. A method of claim 14 wherein the devices are withdrawn at about day 7 or day 10 after insertion.

8. An intra vaginal device of a variable geometry kind capable of being applied into the vaginal cavity of an animal selected from the group consisting of cattle, sheep, deer and goats, retainable therein over a period of time within the range of from 7 to 12 days and then to be withdrawable therefrom to allow the onset of oestrus, said device being characterised in that

on a frame or spine (hereafter “

frame”

) of variable geometry there is a matrix of a cured silicone rubber material that includes greater than 5% and less than 20% by weight progesterone to the weight of the matrix defines and exterior surface (which may be all or part only of the device) of at least 100 cm² contactable once inserted in the vagina of such an animal by the vaginal membrane and/or vaginal fluid(s) of the animal,

the matrix of progesterone containing silicone rubber material has been formed by injection of the uncured progesterone containing matrix as a liquid into a mould for a sufficient time to achieve at a mould temperature or temperatures within the range of from 190°

C. to 195°

C. and a shape retaining at least partial cure thereof,

the total progesterone load (irrespective of whether alpha or beta progesterone or mixtures thereof) being from 1 to 1.5 grams within said matrix,

said surface area is available to at least substantially all of the matrix for progesterone release over a thickness of no greater than about 1 millimeter, and

said device upon vaginal insertion into such an animal is able to achieve and then maintain in the animal for at least seven days a minimum progesterone blood plasma level of 2 nanograms per milliliter of plasma of the animal and which after seven days from insertion will have a residual load in the silicone rubber matrix of less than 60% by weight of its progesterone load at insertion.

10. A method of postponing oestrus or treating anoestrus in an animal which includes the steps of administering into said animal by means of an intra vaginal device sufficient progesterone from a progesterone impregnated silicone rubber matrix where the progesterone content in the matrix is 5% or greater by weight via a surface area greater than 75 cm² so as to achieve on the last few days of insertion a progesterone blood plasma level of from 2 to about 4 nanograms per milliliter, and removing the device after an insertion period of from 5 to 12 days.

12. A method of claim 10 or 11 which includes the administration of oestradiol at or near the time of insertion of said device.

13. A method of any one of claim 10 to 12 which includes the administration of a prostaglandin at about day 6 of about a 7 day or 10 day device insertion period.

16. A method of synchronising the onset of oestrus in a herd of cattle beasts which comprises

administering by means of an intra vaginal device to each animal from a progesterone impregnated matrix of the device an effective amount of progesterone for the period the device is retained intra vaginally, the device having being administered with a progesterone quantity of about 1.35 grams and being removed with a progesterone quantity of the order of about 0.85 grams.