HUP0004980A2 - Intrauterin device for reduction of intensity of menses - Google Patents

Description

Menstrual-reducing intrauterine contraceptive device

Dr. Jenő Havas, Budapest 40%

Ferenc Takacs, Budapest 30%

Dr. Illés Balogh, Budapest 30%

Date of announcement: December 2000

The invention relates to a device suitable for intrauterine placement, comprising plastic arms and a carrier body, and an active ingredient containing zinc, copper, silver and gold.

Until now, devices have only been placed in the uterus for the purpose of contraception. In the early period, intrauterine contraceptive devices made of plastic, without active ingredients, later with hormonal active ingredients were marketed. From the 1970s, types with a more effective, contraceptive-effective metal copper active ingredient that emits copper ions began to be used. These are made up of three main units. The plastic carrier body with arms of different shapes (e.g. T-, Y-shaped), the metal active ingredient - usually a copper wire formed in a spiral shape - placed on the carrier body, and the plastic indicator thread attached to the end of the carrier body.

Devices are known in which the metallic active ingredient is copper (US patents 4,198,966 and 4,353,363) and devices in which the active ingredient is formed from an alloy of copper and/or zinc (Hungarian patents with registration numbers 200,905, 212,696).

There is also a known literature report (Medel, M. et al.: Int. J. Gynaecol Obstet, 14, 494-498 (1976)) according to which contraceptive copper and zinc were wound in the form of wire on the same carrier body, spatially separated from each other. Increased efficiency was experienced during the in vivo use of this device, however, due to the rapid dissolution of zinc, the intrauterine contraceptive device proved to have a very short lifespan (a few months), therefore its practical application could not take place.

A disadvantage of intrauterine contraceptive devices with known metal active ingredients and a sufficiently long lifespan (3-5 years) that has not yet been eliminated is that during their use, the length of menstrual bleeding increases by 2-4 days and its intensity by 20-60%.

We set ourselves the task of developing an intrauterine contraceptive device with a metal active ingredient that causes shorter and less intense menstrual bleeding than previously known devices and has in situ (directly in the uterus) bactericidal and fungicidal properties, while at the same time providing an enhanced contraceptive effect.

The zinc-gold alloy proved to be theoretically suitable for achieving the desired goal, as zinc is well known to reduce bleeding and has bactericidal and fungicidal properties due to the oligodynamic (trace amount) dissolution of gold. However, during the experimental work, it turned out that when combining gold and zinc, only a wire version can be produced that contains a maximum of 17% zinc by weight. However, the alloy containing 17% zinc is not sufficient to achieve the desired effect.

The basis of the inventive idea is the recognition that the wire-shaped active ingredient of the intrauterine contraceptive device, in order to achieve the desired goal, must be formed from a gold-zinc alloy that contains at least two additive metals, preferably copper and silver.

In the presence of additive metals, the zinc content of the gold-zinc alloy can be increased to 30% by weight, the presence of gold provides the bactericidal and fungicidal properties, and the silver content increases the menstrual-reducing properties of the device.

When the device according to the invention is placed in the uterus - while the metal alloy active ingredient is in contact with the uterine fluid - a multitude of galvanic cells are formed. The anode of the galvanic cells is the component of the active ingredient with a more negative electrode potential (zinc, copper), and the cathode is the component with a more positive electrode potential (copper, gold). During the operation of the galvanic cell, the metals forming the anode dissolve during the formation of ions and thus exert their effect, while the cathode remains practically unchanged. The electrochemical dissolution of the metals forming the anode is not only more intense, but also controlled, compared to the spontaneous dissolution of known copper active ingredients.

According to one possible variant of the intrauterine contraceptive device according to the invention, the active ingredient made of zinc, copper, silver and gold is placed on the plastic carrier body in the form of a wire wound in a helical line.

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The plastic carrier body according to the invention can be produced by injection molding technology, by melting the active ingredients and drawing fibers from the melt, and by bending in a known manner.

The intrauterine device according to the invention can be inserted into the uterus in the known manner using an insertion tube and an extension rod. The device is removed from the uterus (this takes place 3-7 years after insertion) by means of an indicator thread, by pulling which the arms of the device close together and it easily slides out through the cervix.

The invention is described in more detail with reference to an exemplary embodiment based on a drawing. In the accompanying drawing,

Figure 1 shows a schematic drawing, partly in section, of a possible embodiment of the device according to the invention.

Example 1

In Figure 1, a wire-shaped active ingredient 2 is wound in a spiral line on a polyethylene carrier body 1 formed with arms. The composition of the active ingredient is: 30% by weight zinc, 57% by weight copper, 3% by weight silver and 10% by weight gold. A plastic indicator thread 3 is attached to the end of the carrier body 1 opposite the arms.

The intrauterine contraceptive device presented in the example releases 360 //g of zinc and 240 pg of copper ions per day (this value is 20-30% more than if the metal active ingredient were made of copper metal alone), resulting in an efficacy of more than 99.5%, while the duration and intensity of menstruation remain practically at normal levels.

Claims (1)

Patent claim 1.) A menstrual-reducing intrauterine contraceptive device, which consists of a plastic carrier body and plastic arms connected to one end thereof, a metal alloy active ingredient placed on the carrier body, and an indicator thread attached to the other end of the carrier body, characterized in that the active ingredient (2) is a copper-gold alloy containing 25-30% by weight zinc and 3-4% by weight silver.