Patent Application
20050279779
The present invention is generally related to a control drop dispensing system and is more particularly directed to such a system including a dispensing tip enabling uniform droplet dispensment.
Applicators or systems for the delivery or instillation of the liquid formulations into an eye by a user have long been known.
Generally, bottles or vials, which contain eye drop formulations, are flexible and have walls sufficiently thin to enable squeezing of the bottle through a nozzle and dispensing orifice.
In use, the user suspends the bottle over an eye to be treated in an inverted or semi-inverted position in order to direct the nozzle toward the eye. The formulation is expelled as the user manually squeezes the wall of the bottle body or a bottom of the bottle. This pressure differential within the bottle drives out a quantity of formulation which exits the vial or bottle via the nozzle orifice as a droplet and descends through gravity into the eye positioned below the nozzle.
While this procedure appears to be straightforward, it often cannot be performed satisfactorily with small volume bottles in order to dispense uniform drops. In addition to handling problems associated with over squeezing or unintentional squeezing of the bottle, the angle of the bottle and nozzle with regard to the eye is significant in determining the droplet size produced.
The droplet size is important in that the dose prescribed to the patient must often be accurately adhered to. If the quantity which is effectively delivered is insufficient, the treatment may not be efficient. On the other hand, if the quantity delivered is too large the surplus in certain cases may cause side effects.
Accordingly, it is important to be able to administer an exact dose of the formulation required and the present invention provides for a controlled drop dispensing tip and system enabling uniform droplet dispensment of the liquid formulation independent of downward angular orientation of the tip.
A controlled drop dispensing tip in accordance with the present invention generally includes a body suitable for attachment to a dispensing bottle and a nozzle having a lumen therethrough for flow of liquid formulation and an orifice in fluid communication with the lumen for the formation of droplets.
A nozzle is formed from a material which enables uniform droplet dispensement of the liquid formulation which is independent of downward angular orientation of the tip.
A system in accordance with the present invention includes a bottle and a liquid formulation disposed in the bottle in combination with the hereinabove described dispensing tip.
More particularly, the tip in accordance with the present invention may be a nanocomposite including a polymer and a nanofiller. The polymer may be low-density polyethylene and the nanofiller may be present in an amount of between about 9% and about 11% by weight, preferably about 10% by weight.
Thus, the present invention provides for a nozzle which is formed from a material comprising a nanocomposite in an amount enabling uniform droplet size dispensement of liquid formulation which is independent of the downward angular orientation of the tip. Preferably, a liquid formulation is Alphagan® or Refresh Liquigel®.
Accordingly, a method for controlling dispensed droplet size includes providing a squeezable bottle, disposing a liquid formulation within the bottle and attaching a dispensing tip to the bottle, the tip being formed from a material enabling uniform droplet dispersement of said liquid formulation independent of downward angular orientation of the tip. Subsequently, the bottle is squeezed with the tip oriented in any downward direction.
The present invention may be more clearly understood with reference to the following detailed description in conjunction with the appended drawings, of which:
With reference to
As illustrated, the droplet size is dependent upon the angular orientation indicated by the letter A of the nozzle 12 to an ordinance 20, as hereinafter described. This variance in droplet size may vary up to 50% or more. For example, a prior art bottle may dispense a droplet size of about 12 microliters at 90%, whereas at an angle A of 45% the same prior art bottle may dispense a droplet size of about 26 microliters.
This variation in droplet size is also dependent upon the droplet size. For example, droplet sizes between 40 and 50 microliters are not as dependent upon orientation of delivery as are droplets of smaller size.
The present invention overcomes this effect through the utilization of nanocomposites.
With reference to
The tip 36 includes a nozzle 42 having a lumen 44 and an orifice 48 in fluid communication with the formulation 34 for the dispensement of droplets 50 of uniform size independent of a downward angular orientation A of the tip 36.
Preferably, the bottle 34 is formed from a low-density polyethylene and droplet size is unexpectedly found to be uniform despite a downward angular orientation of the tip 36 through the use of nanofillers in the low-density polyethylene (LDPE), preferably Dupont resin 206064. Such nanofilled LDPE material may be produced in a conventional manner such as, for example, set forth in U.S. Pat. No. 6,602,966. This patent is to be incorporated herewith in its entirety for the purpose of illustrating the manufacture of a nanocomposite filled polymer useful in the present invention.
A variety of nanofillers for use in nanocomposites are suitable for use in the present invention. Such nanofillers include natural clays (mined, refined and treated); synthetic clays; nanostructured silicas; nanoceramics; and nanotubes (carbon based) as set forth in an article entitled “Enhancing Medical Device Performance With Nanocomposite Polymers in Medical Device and Diagnostic Industry” pp. 114-123 (May 2002). This article is to be incorporated herewith in its entirety for the purpose of describing suitable nanofillers for formation of the nanocomposite in accordance with the present invention for the use within the nozzle 42.
Unexpectedly, it has been found that utilization of a nanofilter such as a montmorillonite clay (Merck Index [1318-93-0]) available from Aldrich Chemical Company, Milwaukee, Wis. in an amount of between about 9% and 10% by weight, preferably about 10% enable a uniform droplet 50 formation independent of downward angular orientation A of the tip 36, as shown in Table 1. Table 1 reports droplet 50 size in microliters as a function of downward angular orientation between 45° and 90° for a nanocomposite of LDPE and nanofiller between 5% and 10% compared with a conventional Teflon material.
As shown for the formulations Alphagan® and Refresh Liquigel® droplet sizes are uniform compared to droplet sizes at 45° and 90° for Teflon and lower percentages of nanofiller. This effect is not as strong with formulations such as Lumigan.
These droplets were formed utilizing the nozzle 36 shown in
As hereinabove summarized a method in accordance with the present invention includes disposing a liquid formulation such as, for example, Alphagan® or Refresh Liquigel® into a squeezable bottle and attaching a dispensing tip to the bottle, the tip being molded, shaped or otherwise formed with a material enabling uniform droplet dispersement of said liquid formulation independent of downward angular orientation of the tip, the material comprises nanocomposites such as hereinbefore discussed.
Uniform droplet dispersement is effected through squeezing the bottle with the tip orientation in a downward direction, such as, for example, between 45° and 90° as illustrated by the angle A in
Although there has been hereinabove described a specific controlled drop dispensing tip in accordance with the present invention for the purpose of illustrating the manner in which the invention may be used to advantage, it should be appreciated that the invention is not limited thereto. That is, the present invention may suitably comprise, consist of, or consist essentially of the recited elements. Further, the invention illustratively disclosed herein suitably may be practiced in the absence of any element which is not specifically disclosed herein. Accordingly, any and all modifications, variations or equivalent arrangements which may occur to those skilled in the art, should be considered to be within the scope of the present invention as defined in the appended claims.
