Double tip drug dispensing and metering device

A double tip drug dispensing and metering device having a bellows or conventional squeeze body container between the double tips. The device being adapted to hold at least two substances in solution which are required to be separated until just prior to dispensation.

BACKGROUND OF THE INVENTION 
Many drugs, particularly those used in treatment of various eye disorders, 
are administered in drop form. The drops of liquid are intended to 
free-fall onto the eye surface, where it is distributed across the exposed 
eye. Dosage of these ophthalmic drugs is often crucial. For example, lower 
than prescribed levels of the drugs can result in failure of treatment and 
consequent progression of the disease and higher levels can result in 
intractable side effects which can also interfere with successful 
resolution. 
Complicating the administration of these drugs is the fact that they are 
often required several times a day and thus to be practical, must be 
administered by the patient rather than medical personnel who are formally 
trained in drug delivery. Patient administration of such drugs has 
resulted in two serious problems, namely, bottle contamination and flow 
rate which must be solved for medications to be successfully administered. 
Container devices having multiple compartments for separately enclosed 
materials to be mixed prior to use are described in U.S. Pat. Nos. 
3,340,873; 3,354,883; 3,397,694; 3,411,503; 4,331,146; 4,412,836; and 
4,330,531, having a thin diaphrame-type membrane separating the two 
compartments. These systems are not considered entirely reliable due to 
its ability to maintain a fluid-tight seal between the compartments. U.S. 
Pat. No. 3,464,414 discloses a rigid walled two chambered mixing vial 
utilizing hydraulic pressure to dislodge a plug member between the two 
chambers. 
SUMMARY OF THE INVENTION 
This invention relates to a double tip drug dispensing/metering device 
adapted to hold at least two substances in solution which are required to 
be segregated until just prior to dispensation, and to provide a means for 
in vitro mixing and dispensing of the mixture. Accordingly, a mixture 
having a limited effective shelf-life once mixed may be preserved for a 
specific or indefinite period by maintaining separately the components 
with or without a preservative until use is desired. While one of the 
constituents must be liquid, the other component may be a liquid or a 
solid. However, the solid component must be in solution prior to entrance 
into the device. 
Liquid dropper dispensers find use in many medicinal areas, particularly 
ophthalmic medication where contamination is a concern. Often dropper 
dispensers are of a plastic "squeeze" type whereby liquid is forced out by 
squeezing the dispenser and residual liquid and air are drawn into the 
dispenser when it is permitted to expand. Therefore, it is an object of 
this invention to provide a double tip dispensing/metering device wherein 
the upper tip serves as a dispensing/metering device and the lower tip 
serves as a means of diluent(s) transfer which is operable without the 
limitations presented in the prior art. 
It is another object of this invention to provide a double tip 
dispensing/metering device that is operable by a patient in need of 
medication comprises of components which must be separated until use is 
required. 
It is further object of this invention to provide a double tip 
dispensing/metering device adaptable to be used with a variety of 
dispensing means. 
Additional objects of this invention will be apparent to persons of 
ordinary skill in the art upon reading the following detailed description 
and appended claims and upon reference of the accompanying drawings. 
DETAILED DESCRIPTION OF THE INVENTION 
It has been found that affixing a second (base) dropper tip to a single 
upper dropper tip dispensing/metering device permits two separate 
substances to be pre-mixed at the desired time thereby increasing the 
individual shelf-life prior to mixing of each substance and reducing 
contamination when mixing is desired along with obtaining a metered 
delivery of the solution (wet/wet or wet/dry) through the upper dropper 
tip. The dispensing/metering device disclosed herein maintains the desired 
liquid(s) and/or solid drug substances in solution thereby enhancing the 
desired flow rate of said drug when passing through said upper tip of such 
device. As previously mentioned, patient administration of drugs has 
resulted in two serious problems, namely, (1) bottle contamination and (2) 
flow rate, which must be solved for these medications to be successfully 
administered. More detailed discussions of the problems are provided 
below: 
(1) BOTTLE CONTAMINATION 
Ideally, the pendent drop formed at the tip of conventional dropper bottle 
should be allowed to free-fall to the surface of the eye. In addition, the 
distance between the dropper tip and the surfaces of the eye should be 
kept reasonably close. This is important so that the momentum acquired by 
the free-falling drop will not be so great as to cause the drop to 
splatter on impact with the eye surface. These conditions: a free-falling 
pendent drop being discharged close to the eye surface, are readily 
accomplished by a trained professional. They are substantially more 
difficult when the drug is self-administered. Gauging such short distances 
is physiologically difficult due to the inability to focus, and in 
addition, the anticipation of impacting drop often causes a blink and 
subsequent loss of portions of the drop. As a result, the user may permit 
the dropper tip to inadvertantly contact the eye surface. 
In either case, small amounts of eye liquids can thus be inadvertently 
permitted to comingle with the liquid of the drop to be delivered. When 
the pressure on the delivery bottle is relieved a small amount of the 
mixed liquids may be drawn back into the bottle. With time, the bacteria 
originally present in the eye, both normal and pathological, will be 
permitted access to a medium which may cause them to proliferate. Thus, 
subsequent drops of medication may re-introduce to the eye either 
excessive levels of typicallyy present bacteria, or large numbers of 
pathogens. Neither situation is acceptable. 
To cope with the problem of contamination, drug manufacturers often 
introduce an antibacterial agent to the drug bottle. In most cases, this 
agent or preservative can only be very effective at supressing the growth 
of bacterial contaminants within the bottle for a specified period of 
time. Unfortunately, there exists a significant population of patients for 
whom these preservatives represent ocular irritants, or in more severe 
cases cause allergic reactions. Such untoward ocular reactions prohibit 
these patients from accessing the drug in this kind of packaging. For 
these patients, single-use, non-preserved drug packaging is a partial 
answer, but at a significantly increased cost and inconvenience. 
(2) FLOW RATE 
Dosage of ophthalmic drugs are regulated on the basis of drops applied to 
the eye. Formation of the drops is directly related to the flow rate of 
the liquid from the bottle. The drops fall from the dropper tip when the 
weight of the pendent drop exceeds the surface tension forces holding the 
drop to the dropper tip. In the ideal case, each drop should be identical 
to the previous one. However, in practice, other factors intervene to 
cause significant variation in drop size. One of the most significant is 
the rate of drop formation. If the drop is formed rapidly, more liquid can 
be "injected" into the body of to drop as it is beginning to break free. 
These drops will be larger, and thus will carry more drug, than if the 
bottle were squeezed very slowly. In extreme circumstances, the drug may 
be ejected in a steady stream. 
The method and device of this invention overcomes three (2) serious 
problems, namely, it enhances uncontrolled flow rate and prolongs the 
shelf-life of at least two substances which are required to be separated 
prior to mixing and dispensing. Contamination of the liquid in the dropper 
bottle is overcome by several features incorporated into the dropper tip 
itself. In addition, these features act to restrict the rate of drop 
formation, irrespective of the variable pressure which may be brought to 
bear on the bottle walls by the user. Thus, with the flow rate metered, 
the drops possess a substantially more repeatale liquid volume. 
A method for practicing the concepts of the invention disclosed herein is 
to hold at least two substances which are required to be separated until 
just prior to dispensation, and provide a means for in vitro mixing and 
dispensing of the mixture. The upper tip of the device disclosed herein 
functions as a dispensing/metering device and the lower tip functions as a 
transfer system for diluent(s) to enter into said device. The upper and 
lower tips are terminal components of a single device having an inner 
bellows or conventional squeeze body chamber having resillant walls 
containing the mixture for application.

It should be understood that the drawings are not necessarily to scale and 
that the embodiments are sometimes illustrated by graphic symbols, phantom 
lines, diagrammatic representations and fragmentary views. In certain 
instances, details which are not necessary for an understanding of the 
present invention or which render other details difficult to perceive may 
have been omitted. It should be further understood, of course, that the 
invention is not necessarily limited to the particular embodiments 
illustrated herein. 
In general, the dispensing/metering device described herein consists of an 
upper T/E cap (1) having screw on threaded attachment (2) and T/E collar 
(2a) for covering upper tip (3) as shown in FIG. II. The upper cap is used 
primarily as a protective cover for the upper tip of the device. FIG. II 
consists of a metered dropper tip having orifice (3) being connected to 
dropper chamber (4) and connecting screw threads (5) for allowing the 
upper cap described in FIG. I to attached and cover said upper tip of FIG. 
II. Upper tip (FIG. II) is permanently connected (preferably by sonic 
welding or the use of an adhesive system) to lower attachment arm (6) of 
FIG. II and the upper bellow (8) of FIG. III thereby connecting both upper 
and lower dropper tips as shown in FIG. IV. Said lower (base) dropper tip 
have conventional squeeze or bellow walls (9) reverse thread screw (10) 
for attachment of base cap (FIG. V), transfer tip channel (11) for 
entrance of medicinal(s) into storage bellow chamber (9) through sealed 
tip orifice (12) being located at the base of lower dropper orifice tip 
(12) which connects with passage channel (11). 
In FIG. 3, the base dropper transfer tip (12) of the device disclosed 
herein is covered by a reverse thread screw cap FIG. V having reverse 
threads screw (13) and tip seal (14) for permanently sealing the lower tip 
after transfer of the medicinal(s) (wet/wet or wet/dry) into storage 
chamber (9). 
The dispensing/metering device disclosed herein is useful in administering 
at least two substances which are required to be separated until just 
prior to dispensation. Said device consists of two dropper tips, the upper 
tip serving as a dispensing/metering device tip and the lower tip serving 
as a transfer device for substance(s) required to be segregated until time 
for pre-mixing. 
In practicing the concept of this invention, at least two diluents (wet/wet 
or wet/dry) are separately pre-mixed with or without a preservative until 
complete solution is obtained. The diluents are then transferred into the 
bellow or conventional squeeze body container (6 and 9) via lower base 
transfer orifice tip (12) of the device. If one of said diluent(s) is a 
solid, then complete solution is required before transferring through said 
base transfer tip. It is not critical as to which diluent is first 
transferred into the bellows or conventional squeeze body container (6 and 
9). In fact, the diluents can be pre-mixed and then transferred into the 
body container of the device and stored until treatment is desired. 
In FIG. II, the orifice progressively gets larger from its inception to 
point (3). The lower part of the orifice (3) has a dimension of from 0.002 
to 0.010 .+-.0.001 inch, preferably from 0.004 to 0.008 .+-.0.001 inch and 
most preferably 0.006 .+-.0.001 inch. The upper part of orifice (3) at 
point (3) has a demension of 0.060 to 0.10 .+-.0.005 inch, preferable 
0.075 to 0.25 .+-.0.005 inch and most preferable 0.093 .+-.0.005 inch. 
In FIG. III, one skilled in the art can readily appreciate that the 
dimensions of transfer tip channel (11) which connects to orifice (12) is 
not critical. In practicing the concept of this invention, it is found 
that dimensions in the range of 0.015 to 0.040 .+-.0.005 inch are 
applicable with 0.023 .+-.0.005 inch being preferred.