[0001] This invention is concerned with a novel design of a dropper tip useful on conventional
medicine droppers used primarily for dispensing ophthalmic medications.
[0002] The conventional ophthalmic drug delivery system, FIG. 1, consisting of a dropper
tip, 1, and squeeze bottle, 2, is intended to deliver th,e medication in a drop by
drop manner, the drops being of a uniform predetermined size. The drop size control
is achieved by means of the hydraulic resistence presented by a small diameter channel,
3, forming the beginning of the straight delivery channel, 4, in the dropper tip,
1, having a diameter of about 0.006 inches or 0.150 mm. which restricts the flow from
the squeeze bottle, 2. This conventional drug delivery system generally serves the
intended purpose but in the hands of many patients does not always result in discrete
drops but rather streaming of the liquid resulting in loss of medication, and possibly
soiled clothes and other fabrics.
[0003] In addition conventional dropper tips with the narrow channel, 3, are commonly fabricated
from plastics by injection molding techniques which require a complex technology not
readily available in less developed countries.
[0004] Now with the present invention there is provided a dropper tip providing better delivery
control, that requires a lower level of technology to fabricate, thus lowering the
cost per unit device, and permitting fabrication practically anywhere in the world.
[0005] These advantages are achieved by the design of the tip, 5, shown in Fig. 2, wherein
entry to the delivery channel, 6, is not through a narrow, channel, but rather through
an orifice, 7, which is not concentric with the delivery channel but rather at an
angle, preferably right angle, to it on the side of the hub, 8.
[0006] In the novel tip of this invention the restriction to flow or hydraulic resistance,
is provided, not by a narrow channel that is difficult to fabricate, but in part by
a convoluted delivery path causing the liquid flow to change direction as it enters
the delivery channel which impedes the conversion of the internal static energy provided
by squeezing of the bottle into the kinetic energy of the liquid flow.
[0007] In addition, the cross-section of the orifice can be of any shape such as circular,
triangular, semicircular, irregular or rectangular, preferably the latter, in which
case the hydraulic resistance to fluid delivery is determined in part by the dimensions
of the rectangle a long and narrow rectangular orifice providing greater hydraulic
resistance than a square orifice of the same cross-section area. Regardless of shape,
the orifice has a cross-sectional area of about 0.015 to 0.02 mm²
[0008] The size and shape of the orifice, 7, can be controlled by simplified molding techniques
within desired specifications.
1. A dropper tip for the controlled delivery of a liquid providing entry to the delivery
channel by an orifice that is not concentric with the delivery channel.
2. The dropper tip of Claim 1 wherein the orifice has a cross-sectional area of about
0.015 to 0.02 mm²
3. The dropper tip of claim 2, wherein the cross-section of the orifice is non-circular.
