Two-bottle assembly for preparing and dispensing a solution

The invention relates to an assembly for preparing and dispensing a solution and to the stopper for such an assembly, said assembly comprising a first bottle containing a first liquid component, with an elongated head; a second bottle containing a second component, liquid or solid; a stopper for this second bottle presenting a recess whose shape is homologous of the head of the first bottle, and in which said head is for example screwed. The bottom of the recess is constituted by a membrane of deformable material comprising an axial orifice which is hermetically closed, in the absence of deformation of the membrane, by the natural radial constriction of the material of the membrane. By screwing the first bottle in the stopper, the membrane is axially deformed and the orifice is radially distended, thus allowing the two bottles to be placed in communication in reversible manner. The invention also relates to a process for making the stopper.

BACKGROUND OF THE INVENTION 
The present invention relates to an assembly for preparing and dispensing a 
solution as well as to a stopper for this assembly, and to the process for 
manufacturing the stopper. 
Such an assembly is generally presented to the user in extemporaneous form, 
i.e. to be prepared at the moment of use. 
A first bottle contains the solvent and a second bottle contains the 
substance to be dissolved, for example in lyophilized form; this substance 
may also be in liquid form, the solution then being prepared by mixing the 
two liquid components at the moment of use. 
To prepare the solution, the user opens the two bottles, pours the solvent 
into the second bottle containing the substance to be dissolved, stoppers 
the latter before stirring it in order to complete dissolution or mixture 
of the two components. 
This manipulation is not always easy, as the bottles are often of small 
dimensions. A certain skill is necessary and there is always a risk of 
spilling part of the solvent when the user pours said solvent into the 
second bottle and when he stoppers the latter, particularly in the case of 
such stoppering being effected by means of a teat for instillation which 
is often difficult to fit on the bottle. 
In addition, as both bottles must be opened, there are also risks of 
contamination from the user's fingers during preparation or when 
stoppering the second bottle; it is therefore impossible to guarantee that 
the preparation made in this manner is perfectly sterile. 
It is one of the objects of the present invention to overcome these 
drawbacks by proposing an assembly allowing the sterile preparation of the 
solution. In fact, the assembly according to the invention does not 
require that the bottles be opened. 
To this end, the assembly according to the invention comprises: 
a first bottle containing the first liquid component, of which the neck 
terminates in an elongated head traversed by a longitudinal conduit 
placing the interior of the bottle in communication with the outside, 
a second bottle containing the second component, liquid or solid, 
a stopper for this second bottle, presenting on its outer face a recess 
whose shape is homologous of that of the head of the first bottle, and of 
which the bottom is separated from the interior of the second bottle only 
by a thin membrane of elastically deformable material, 
this membrane further having an axial orifice passing therethrough, which 
is hermetically closed, in the absence of deformation of the membrane, by 
the natural radial constriction of the material constituting the membrane, 
the penetration of the head of the first bottle into the recess of the 
stopper producing an axial deformation of the membrane and a radial 
distension of the orifice opening a passage for a liquid through the 
membrane, so that this passage allows a transfer of liquid from one bottle 
into the other after these two bottles have been joined together, 
means further being provided to produce a differential pressure between the 
atmospheres of the two bottles to force the transfer, into the second 
bottle, of the liquid contained in the first bottle. 
The recess in the stopper is advantageously provided with an inner thread, 
the head of the first bottle being provided with a homologous outer 
thread, to allow the two bottles to be joined by screwing. 
In a variant embodiment, the recess in the stopper may be a cylindrical 
recess of radial dimensions slightly less than the radial dimensions of 
the head, which is cylindrical, of the first bottle, the penetration of 
the head of the first bottle into the stopper producing a radial 
deformation of the stopper, ensuring clamping thereof on the head of the 
first bottle to allow the two bottles to be joined. 
The axial orifice of the obturator is preferably formed by pre-boring the 
membrane, without removal of matter. This pre-boring may for example be 
effected by penetration through the membrane of a solid needle, during a 
stamping step when the stopper is being manufactured. 
The stopper advantageously possesses a substantially flat upper stop 
surface, the head of the first bottle extending, in projection above a 
shoulder of the neck of this bottle, over a height greater than the depth 
of the recess with respect to the upper surface of the stopper, the axial 
deformation of the membrane being limited by the shoulder of the neck of 
the first bottle coming into abutment against the upper surface of the 
stopper of the second bottle. 
The assembly may be made according to a first embodiment, in which the 
differential pressure between the atmospheres of the two bottles is 
produced by outside compression of the wall of the first bottle, the 
latter being made of a deformable material. 
In a second embodiment, the differential pressure between the atmospheres 
of the two bottles results from a vacuum made inside the second bottle, 
the latter being made of a rigid material. 
In a third embodiment, the first bottle presents a generally cylindrical, 
rigid body in which slides a piston mobile under the effect of outside 
ation so as to create the differential pressure necessary to force the 
transfer of liquid from one bottle into the other.

Referring now to the drawings, in FIG. 1 which corresponds to the first 
embodiment, the first bottle 10 comprises an envelope 11 made of supple 
material containing a liquid component 12. This bottle is closed in its 
upper part by a stopper presenting an elongated head 13 traversed by a 
longitudinal channel allowing the contents to communicate with the 
atmosphere and these contents to be expelled by pressure on the supple 
envelope 11. The head 13 is provided with a thread 14 on which is screwed 
a cap 70 protecting the head 13 when the assembly is not in use. A 
transparent cap 80 may also be fitted on this first bottle. 
The second bottle 20 comprises a rigid envelope 21, for example made of 
plastics material or glass, containing the second component 22, liquid or 
solid (for example in the form of lyophilisate). This second bottle is 
extended by a cylindrical neck 23 in which a stopper 30 is fitted. 
This stopper is shown in greater detail in FIG. 17: it comprises a recess 
33 in its upper part, of which the bottom is closed only by a thin 
membrane 31 through which passes an axial orifice 32 which is hermetically 
closed, in the absence of deformation of the membrane, by the natural 
radial constriction of the material constituting the membrane. This 
membrane is made of elastically deformable material, with the result that 
any pressure exerted on the bottom 37 of the recess 33, which is for 
example a flat bottom, will produce an axial deformation of the membrane 
and a radial distension of the orifice opening a passage for a liquid 
through the axial orifice 32. 
The axial orifice is preferably formed by pre-boring the membrane, without 
removal of matter, for example by penetration through the membrane 31 of a 
solid needle whose diameter is between 1.5 and 3 mm, for a thickness of 
membrane e of between 0.5 and 1.5 mm. 
This pre-boring stage may for example be simultaneous with a stopper 
stamping stage, after said stopper has been moulded in an elastically 
deformable material, for example a conventional elastomer or rubber as 
used in the medical domain for injections. 
The recess 33 of the stopper is further provided with an inner thread 34 
homologous of the thread 14 of the head of the first bottle. The upper 
surface of the stopper is a flat surface which will serve as stop 
shoulder, as will be seen hereinafter. Finally, the lateral surface 36 is 
a cylindrical surface of revolution allowing the stopper to be 
force-fitted in the cylindrical neck 23 of the second bottle. 
Furthermore, the stopper fitted in this bottle (FIG. 1) is permanently 
maintained thereon by a ring 40 crimped between the upper surface 35 of 
the stopper and a peripheral flange 24 of the neck of the second bottle. 
In addition, before it is used, the recess of the stopper is closed by a 
disc 50, for example of aluminum, itself maintained by a second crimped 
ring 60 which will be torn off when the assembly is used. 
To use the assembly, the user offers (FIG. 2) the head 13 of the first 
bottle 10 opposite the recess 33 of the stopper of the second bottle 20. 
By screwing the head 13 in the recess (FIG. 3), the end 15 of this head 
(which may for example be rounded in form) is brought into contact with 
the bottom 37 of the recess of the stopper. By continuing screwing, the 
penetration of the head will produce a deformation of the membrane 31, as 
indicated hereinabove, to allow the orifice 32 to distend and the two 
bottles to be brought into communication. 
The stroke of the head of the bottle, and therefore the amplitude of the 
deformation, is advantageously limited by a shoulder 15 at the base of the 
head of the first bottle coming into abutment with the upper surface 35 of 
the stopper: in this way, the deformation of the membrane 31 remains 
elastic and therefore reversible, withdrawal of the first bottle by 
unscrewing ensuring hermetic stoppering of the second bottle. 
The user then exerts (FIG. 4) a pressure on the walls of the first bottle, 
so as to cause all the liquid contained therein to pass into the second 
bottle, where the lyophilisate dissolves. The mixture thus formed is 
rendered homogeneous by shaking (FIG. 5) the assembly formed by the two 
bottles. However, it will be noted that, if it is desired simply to keep 
the prepared mixture in the second bottle, the first bottle may be 
unscrewed and discarded, and the second bottle may be shaken alone, thanks 
to the hermetic closure resulting from the return of the membrane into its 
initial position. 
It may also be desired to return the mixture into the first bottle: in that 
case, the mixture is transferred (FIG. 6) by turning the assembly upside 
down and successively pressing on and releasing the envelope of the first 
bottle. Once all the liquid has been transferred into the latter, it is 
separated from the second bottle (FIG. 7): the mixture is then ready to be 
dispensed (FIG. 8), the head 13 of the first bottle then acting as head 
for instillation. 
In another embodiment, shown in FIG. 9, the first bottle 110 is not a 
supple bottle, but a rigid, cylindrical syringe body 111 in which slides a 
piston 115 under the action of a syringe rod 116. 
In this case, the two bottles 110 and 120 may be joined together not by 
screwing, but by force-fitting; the recess of the stopper 130 is a 
cylindrical recess whose radial dimensions are slightly smaller than the 
radial dimensions of the head 113 of the syringe, which is also 
cylindrical, connection being ensured by force-fitting the head 113 in the 
deformable stopper 130. Once the mixture is made and the solution 
transferred into the syringe body 111, the latter is separated from the 
second bottle 120 and an injection needle is adapted on head 113. This 
modus operandi presents the advantage, over the conventional technique 
where a rubber stopper is pierced by the injection needle (therefore by a 
hollow needle), of producing no particle of rubber which contaminates the 
solution at the moment of piercing. 
Another embodiment is shown in FIGS. 10 to 12: the two bottles 210 and 220 
are rigid, and a vacuum has been made in the atmosphere in the second 
bottle 220 to allow the subsequent transfer of the liquid from one bottle 
into the other. The bottle 220 is closed by a stopper 230 identical to the 
one described hereinabove with reference to FIG. 17, the tightness of the 
membrane in the absence of deformation maintaining the vacuum in the 
bottle. 
This bottle is further provided in its lower part with an orifice 224 for 
communication with the open air, which is normally closed by a stopper 
225, for example force-fitted thereon. 
When the two bottles are connected by screwing (FIG. 11), the vacuum 
present in the bottle 220 will produce a suction of the liquid from bottle 
210, as soon as the deformation of the membrane is sufficient to effect 
communication of the two bottles. 
Transfer back into the first bottle 210 is ensured (FIG. 12) by turning the 
assembly upside down and removing the stopper 225: by placing the 
atmosphere in bottle 220 at atmospheric pressure, the liquid is delivered 
into bottle 210. 
In a variant, in order to improve the conditions of sterility of the 
preparation, it is possible to give the second bottle 220 the form shown 
in FIG. 13. The body 221 of this bottle is cylindrical in form, and a 
piston 226 enables the contents of the bottle to be separated from the 
orifice 224, while allowing, by sliding, the establishment of atmospheric 
pressure when the stopper 225 is withdrawn. 
In another variant, shown in FIGS. 14 to 16, the first bottle 310 is 
provided with two heads 313, 315, one at the top and the other at the 
bottom. The head 315 performs the same role as indicated hereinbefore, 
screwing in the recess in bottle 320. This head may for example be closed 
by a stud element 316 which can be torn off when the assembly is used. 
Once the two bottles are connected together (FIG. 15), the contents are 
sucked from the first bottle 310 to the second bottle 320, as before, by 
reason of the vacuum made in the atmosphere of the latter bottle. 
The assembly may then be directly used after being turned upside down (FIG. 
16), without disconnecting the two bottles: the second head 313 in that 
case serves to instill the mixture. This head had hitherto remained 
protected and hermetically closed by a cap 370, for example a screw-on 
cap.