Note: Descriptions are shown in the official language in which they were submitted.
~ 21 89870
W096/0l092 r~llr- 5
DEVICE FOR TEIE RELEASE O~ AN ACTIVE AGENT
.
The invention relates to an intrauterine device
substantially in the shape of a T for r~ ARin~ an active
agent like a hormone.
A widely used intrauterine contraceptive is a T-shaped body
5 made of plastic r ~ in~ an elongated stem part one end
of which i6 connected with a transverse part so that the
stem and the transverse part together form a body
substantially in the shape of a T. The stem is partly
twisted by a copper wire which ig capable of rell~A1lin~
10 copper ions. The device is inserted into the uterus by a
separate insertion device. Attached to the device is a
thread which is so long that it extends outside the uterine
cervix when the device is in inserted position.
T-shaped intrauterine devices releasing h~ -~ and other
15 active agents for contraception and treatment of hl ~ A 1
disorders are also known in literature. US patent 3,935,860
de6cribes a T-shaped body comprising a reservoir surrounded
by a wall wherein the hormone is in~onm; 1r~ with the
carrier. The wall is made of a substance which releases the
20 active agent at a controlled rate. The carrier which is
solid or liquid contains the active agent which is
progestational or estrogenic hormone.
US patent 4,014,988 describes also a T-shaped body which
comprises a reservoir ~uLl~,ullded by a wall containing
25 progestational hormone int~ d with a carrier. The wall
is made of a material which releases the hormone at a
controlled rate.
US patents 4,264,575 - 4,264,578 describe intr~luterine
devices in which the active agent is dispersed into a
30 silicon polymer which releases the agent at a controlled
rate. The patent publications do not separately describe
21 8987~` ~
W0 96/01092 ~ r- S
any particular device conf igurations but it i8 mentioned
that the device may have e.g. a shape of a T.
US patent 4 ,180, 064 di6closes various intrauterine devices,
a T-shaped device among others, wherein the progestational
5 or estrogenic hormone is in~-~rmi Y~r~ with a hiori~r~ Ah
polymer .
Common to the above T-shaped devices releasing hormone or
other active agents is that both the stem and its
transverse part together form one single piece. For this
10 reason the device is complicated to manufacture and it i8
expensive and insertion of the device into the uterus is
problematic .
A commercially available levonorgestrel releasing
contraceptive comprises a T-shaped device with a sheath-
15 like polymer reservoir containing the hormonelevonoly~a Llcl, the reservoir being f itted around its
vertical polyethylene stem. One way of fabric~ting it has
been p--hl i ~h~ in the international patent application
PCT/FI93/00296. One aspect associated with this solution is
20 that while the device is in inserted position in the
uterus, release of the active agent takes place only in the
lower part of the uterus. From the point of view of the
results of treatment with active agents used for
contraception as well as for other purposes, it is
25 advantageous that their release takes place as high in the
uterus as possible. This result can be achieved if the
reservoir containing the active agent is placed higher in
the T-piece than in the known levonorgegtrel r~ i n~
contraceptive .
The purpose of this invention is to eliminate the above
rlra~hal~k~ and to obtain a novel, essentially T-shaped
intrauterine device containing an active agent which is the
most effective po~ihle from the point of view of the
35 treatment and which is simple to manufacture and easy to
_ _ _ _ _
2 1 89870
WO 96/01092 1 ~/r~
insert Lnto the uterus.
A so-c~lled bundle tie a fastening means widely used, for
instance, in the f ield of packaging . It compri6es a strip
of flexible material, e.g. plastic, with a ring formed at
5 its one end having grooves on its inner side. The other end
of the strip is passed through the ring thus forming a
loop. The strip is provided with ridges essentially over
the entire length of the strip which fit into the grooves
formed in the ring. The ridges and the grooves are so
lO shaped that pulling of the strip to tighten up the loop is
possible whereas pulling of the strip in opposite direction
to loosen the loop is impossible.
Some of the solutions according to this invention are based
on the utilization of the bundle tie technique.
lS The ob~ect of the invention is therefore an intrauterine
device essentially in the shape of a T for releasing an
active agent comprising an elongated stem, to one end of
which an elongated transverse part is ~oined so that this
and the stem together form the body essentially in the
20 shape of a T. The invention is characterized in that the
transverse part comprises a polymer matrix reservoir
containing the active agent and that the stem either
comprises a polymer matrix reservoir containing the active
agent or that it is a part which contains no active agent.
25 According to one: 'i t the stem is secured to the
transverse part by tightening a fastening means at the end
of the stem partly or wholly around the transverse part.
.
The reservoir containing the active agent may be surrounded
by such a ~ e which is capable of releasing the active
30 agent at a predet~rm; nPd rate .
The active agent may be e . g . a hormone suitable f or the
treatment of menopausal symptoms or contraception,
21 89870
WO96~01092 ~ /rl .
particularly estrogenic or progestational hormone.
The matrix reservoir containing the active agent and the
surrounding ' n~ CAn be made of the same or different
polymer or polymer mixture. It i9 essential that both the
material of the matrix and the possible surrounding
',rAnP is made of a flexible polymer. Silicon polymers
are particularly suitable for this purpose.
The invention is described in the following referring to
the enclosed drawings in which
lO Fig. l shows a plan view of the T-shaped body according
to the invention in which the stem is secured to
the transverse part by tightening the fastening
means formed at the end of the stem around the
transverse part
15 Fig. 2 shows a side view of the T-shaped body of Fig. l
Fig . 3 shows the T-shaped body f itted into an insertion
tube
Fig. 4 shows a cross-sectional view of the stem which
together with the fastening means together with
the stem form a uniform piece
Fig. 5 shows the stem of Fig. 4 according to a second
embodiment
ig. 6 shows the stem of Fig. 4 accor~lin~ to a third
- i t
5 Fig. 7 shows the stem of Fig. 4 according to a fourth
t
Fig. 8 shows the stem of Fig. 4 according to a fifth
~mho~l i t
~ 2 ~ 8q87~
Wo 96101092 . ~I~rL _ v
Fig. 9 shows the stem of Fig. 4 according to a sixth
Fig. 10 shows the stem which is to be ~oined to the
transverse part and in which the fastening means
is a separate piece which can be secured to the
stem
Fig. 11 shows a T-shaped body where also the stem is a
polymer matrix reservoir containing the active
agent
Fig. 12 shows a fastening means suitable for joining the
stem of Fig. 11 and the transverse part together
Fig. 13 shows the fastening means of Fig. 12 according to
a second F.mhn~l i L
5 Fig. 14 shows a T-shaped body with two transverse parts
~oined to the stem
Fig. 15 shows a stem suitable for ~oining two transverse
parts .
Fig. 1 shows a T-shaped body 10 according to the invention
20 wherein the stem 20 is secured to a transverse psrt 40 by
tightening the fastening means 22 formed at the end 21 of
the stem around the transverse part 4 0 according to the so-
called bundle tie technique. Securing to a ring 25 located
at the end of the fastening means takes place in the way
25 which is illustrated more clearly e . g . in Figs . 4 and 5 . A
pull-out thread 50 is attached to the opposite end 23 of
the stem 20. Fig. 2 shows the T-shaped body of Fig. 1 seen
from the side. In this solution the transverse part 40
comprises both a polymer matrix reservoir 41, which
30 contains the active agent, and a covering membrane 42
2189a7
Wo 96/01092 r~
6urrounding the reservoir 41 which is capable of
controlling the release rate of the active agent. The ends
43a, 43b (Fig. 1) of the transverse part 40 are preferably
uncovered. IIence the release rate of the active agent nt
5 the ends is higher than from the area covered by the
-- ^ 42 and this is an advantage from the point of view
of the result of treatment.
Fig. 3 shows the T-shaped body seen from the front fitted
into a cross-sectioned insertion tube 51. The size of the
10 ring 25 of the fastening means 22 most preferably matches
with the outer diameter of the insertion tube 51. Figure
shows that the diameter of the fastening means tapers
upwards. This shape is particularly suitable from the point
of view of the insertion. The transverse part 40 is made of
15 a very f lexible polymer material and as the insertion
device is introduced through the uterine cervix, the wings
44a, 44b of the body 40 on both sides of the fastening
means 22 readily bend downwards so that they follow the
insertion tube as indicated by the dashed lines upon
20 penetrating the uterine cervix. The polymer material must
be flexible enough so that the part 40 straightens again
inside the uterus.
Fig. 4 shows as a cross-section the stem 20 of the T-shaped
body of Figs. 1-3 and one ~mhofli- t of the fastening
25 element bent into a loop. The fastening means 22, which is
of the same piece as the stem itself, comprises also the
loop 25 iormed at its end. The fastening means 22 is
provided, at least within the part to be secured, with
ridges 27 which lock with the grooves 26 formed on the
30 inside of the ring 25. The ridges 27 and the grooves 26 are
so shaped that tightening in the direction of the arrow is
allowed but loosening in the opposite direction of the
arrow is prevented. If desired, the stem 20 can be provided
with ridges over the entire length in which case ad~ustment
35 pQ88i hil; ties are not limited .
,
2t 89~370
WO96101092 I~l/rL_~ /u
In Fig. 5 the ridges 27 have been replaced by a single
dovetail barb 27 ' which locks against the lower surface of
the ring 25.
Fig. 6 shows a third r~mho~ t of the stem 20 and the
5 fastening means. Here also the fastening means is of the
same piece as the stem itself and it comprises an annular
ring 25 with a hole of exactly the right size to allow the
spherical parts 28 fitted along the stem to be pulled
through the hole by pulling hard enough in the direction of
l O the arrow .
Fig. 7 shows a fourth ~ i t of the stem and the
fastening means. The fastening means 22, which together ~~
with the stem constitute one piece, is a loop whose ends 20
and 30 can be locked to one another by means of a dovetail
15 barb 27 ~ formed at the end 29 and a groove 26 ' shaped at
the end 3 0 .
Fig. 8 shows a fifth: ~)nll~ t of the stem and the
fastening means. ~he end 29 of the fastening means 22
forming a loop is provided with ridges 27 and the loop can
20 be locked by pushing the end 29 with the ridges to a
desired depth into the opposite end 30 which is provided
with such grooves 26 the pull-out of the end 29 out of the
end 30 is prevented.
In Fig. 9 the fastening means 22 forms an open loop whose
25 ends 29, 30 need not be interlocked. In the assembly of the
-shaped body the transverse part is pressed down between
the flexible ends 29, 30. Due to the tension of the ends
29, 30 of the loop, the transverse part is held fast in the
grip of loop.
30 Fig. lO shows a stem in which the fastening means 22 is
separate loop which can be locked to the stem 20. It has
barbs at both ends 29, 30 and locking takes place as the
ends are placed against one another and are pushed into the
2189~7
WO g6/01092 ~ llr~
groove 26 formed into the shaped end 21 of the stem.
Flg. 11 shows a T-shaped body in which also the stem 20 is
a polymer matrix reservoir containing the active agent. The
stem 20 and the transverse part 40 are attached to each
S other with a separate fastening means 22 which is shown in
more detail in Fiys. 12 and 13. The principle of operation
of the fastening means of Fig. 12 .~ uAds to the loop
shown in Fig. 9. The loop 22 in the vertical plane holds
the transverse part of the T-shaped body and the open loop
10 33 in the horizontal plane holds the Qnd of the stem. Due
to the tension of the ends 34, 35 of the loop 33, the end
of the stem is held fast in the grip of the loop.
Fig. 13 shows a solution which is an alternative to that of
Fig. 12. Also in this solution the loop 22 in the vertical
15 plane holds fast the transverse part of the T-shaped body
and the loop 33 in the horizontal plane holds the end of
the stem. The ends are interlocked acrr~r~lin~ to the
principle of the solution of Fig. 7.
Fig. 14 shows a T-shaped body in which two transverse parts
20 40 and 40' are ~oined to the stem both of which comprise
polymer matrix reservoirs containing the active agent.
Fig. 15 shows a stem 20 suitable for ~oining two transverse
parts. The fastening means 22, which o ~ ,nds to that of
Fig. 9, holds the upper transverse part 40 in place. The
25 lower f~stening means 22', which functions according to the
same fastening principle as the upper fastening means 22,
opens to one or the other side and fastening of the lower
transverse part 40 ' takes place by pushing it into the loop
22 ' from the side .
30 In those solution where the device 10 comprises two
separate polymer matrix reservoirs, either so that the
device has two transverse parts 40, 40' or so that also the
stem 20 forms a polymer matrix reservoir, the reservoirs
.
2 1 89870
WO 96tO1092 r~,l/rl . v
can contain the 6ame or different active agents. For
example, one reservoir may contain hormone and the other
re6ervo~ r agent which prevents inf lammation .
It is obvious to a specialist in the field that different
5 : ' ' i ts of the invention can vary within the limits of
the claims presented hereinafter.
