Patent Description:
Botulinum toxin, popularly known by one of its trade names, Botox, is a protein and neurotoxin that is used in various cosmetic and medical procedures. In cosmetic applications, a botulinum toxin injection may be used to prevent the development of wrinkles by paralizing facial muscles. In non-cosmetic applications, botulinum toxin may be used to treat conditions of excessive and inappropriate muscle contraction, migraine, spasticity (persistent states of muscle contraction), sphincter contraction, eye-movement disorders, tics and tremors.

Botulinum toxin is administered to a patient by means of an injection using a suitable syringe with a needle hub assembly. The needle of the needle hub assembly is passed through the skin to reach subcutaneous tissue and subsequently, the botulinum toxin is injected by pushing the plunger of the syringe inside the barrel of the syringe such that the toxin is expelled from the syringe at the distal end thereof via the needle hub assembly.

United States patent application publication <CIT> discloses a disposable syringe which includes a barrel, a needle assembly in fluid communication with the barrel, and a plunger movable in an accommodation chamber of the barrel, wherein said needle assembly includes a needle seat sleeved on a small-diameter wall portion of the barrel, and a tubular insert extending axially into a duct of the needle seat and defining a fluid channel, and a needle cannula in fluid communication with the fluid channel, wherein a space minimizing member is disposed to be in a fluid-tight engagement with an inner surface of the small-diameter wall portion, and has a tubular grip surface which defines a passageway fluidly communicated with the duct such that the insert is in a fluid-tight engagement with the grip surface to thereby communicate the channel with the chamber, as a result of which the amount of residual medication fluid in the barrel after completion of an injection operation can be minimized. A further document dealing with the problem of how to minimize the amount of residual medication fluid is <CIT>, which discloses the combination of features of the preamble of claim <NUM>.

Syringes used to administer botulinum toxin injections normally comply with ISO standards. This enables the use of every suitable needle hub assembly with every suitable syringe to inject the botulinum toxin.

However, although certain properties of the respective needle hub assembly and the syringe are standardized, the used needle hub assembly and the used syringe do not need to be designed for optimal use of the fluid inside the syringe. This means that, for instance when using a certain needle hub assembly with a certain syringe, an amount of botulin toxin may remain inside the syringe and/or the needle hub assembly after completely inserting the plunger into the barrel of the syringe. Since botulinum toxin is a rather expensive product, it is desirable that only as little as possible botulinum toxin remains inside the needle hub assembly and/or the syringe.

Therefore, it is an object of the present invention, which is defined in claim <NUM>, to provide for an improved needle hub assembly for use on a syringe that enables improved emptying of the syringe and/or the needle hub during administering of the botulinum toxin to a patient.

To this end, a first aspect of the invention is directed to a needle hub assembly for a syringe, said assembly having a longitudinal axis. The needle hub assembly comprises a needle hub body having a syringe connector for receiving an attachment member of a syringe at a first end of the body and a needle receiving portion at a second opposing end of the body. The needle hub assembly also comprises a needle extending from the needle receiving portion. The syringe connector comprises a substantially conical receiving opening for receiving a syringe attachment member, at least a distal end thereof, wherein an entrance area of the receiving opening has a cross sectional dimension of approximately <NUM> to approximately <NUM>, wherein an inner circumferential wall of the receiving opening that extends between an entrance area perimeter and an upper surface perimeter tapers from the entrance area towards the upper surface with <NUM>%, wherein the length of said opening, measured along the longitudinal axis is between <NUM>-<NUM>, preferably approximately <NUM> +<NUM>.

The needle hub assembly according to the invention does not strictly comply with the relevant ISO standard ISO594-<NUM>. According to said ISO standard, the length of the receiving opening is of sufficient length to ensure proper engagement of the needle hub assembly to the attachment member of the syringe. However, applicant found that the engagement of the needle hub assembly with a syringe, when the length of the receiving opening has the above indicated dimension, is adequate. In order to further enhance the extent of engagement, the needle hub body may be made of a material that has a greater hardness than the material of the syringe to be used. Using harder material provides for a further reduced disengagement risk of the needle hub assembly. However, it is noted that the needle hub body may instead be of a material with a hardness similar to the material of the syringe. The extent of engagement between said parts, when complying with the above indicated length of the receiving opening according to the invention, is sufficient for a proper functioning of the syringe.

With the needle hub assembly according to the invention, when connected to a syringe in order to administer botulinum toxin to a patient, substantially no, or at least as little as possible, toxin is left in the syringe and/or needle hub assembly after completely sliding the plunger into the barrel of the syringe. Since no, or at least as little as possible, toxin is left in the syringe substantial cost savings may be obtained.

According to a preferred aspect of the invention, a syringe having a longitudinal axis may be provided, wherein the syringe is provided with a needle hub assembly according to the invention. The syringe may comprise a barrel extending longitudinally between a proximal end and a distal end of the syringe, said barrel comprising an attachment member for attaching to the needle hub assembly. The syringe may further comprise a plunger that is slidably received in the barrel, wherein the plunger comprises a sealing element that is arranged at a distal end of the plunger and configured to at least cooperate with an inner side of the attachment member. The syringe connector, the attachment member and the sealing element may be configured to cooperate such that, when the plunger is completely inserted in the barrel, a space enclosed by the syringe connector, the attachment member and the sealing element has a volume that is less than <NUM>µl. Preferably, the space has a volume that is between <NUM>µl and <NUM>µl. For instance, the space may have a volume that is less than <NUM>µl. By optimally gearing the designs and dimensions of the syringe connector, the attachment member and the sealing element to another, an enclosed space is obtained with a volume that approaches zero. With such syringe, the amount of botulinum toxin left in the syringe after administering the injection, is minimized. Applicant has found that with the above described syringe a reduction of approximately <NUM>% of botulinum toxin losses can be obtained in comparison with the use of a standard syringe with a standard needle hub assembly. Optimally, the enclosed space may have such a volume that zero fluid is left in said volume after inserting the plunger completely in the barrel.

Since during treatment with botulinum toxin, a patient is subjected to multiple injections, providing a <NUM>-<NUM> needle, for example a <NUM> needle, to the needle hub assembly as presently disclosed, adds to minimizing the trauma for the patient during said injections.

The aforementioned and other features and advantages of the invention will be more fully understood from the following detailed description of certain embodiments of the invention, taken together with the accompanying drawings, which are meant to illustrate and not to limit the invention.

It is noted that identical or corresponding elements in the different drawings are indicated with identical or corresponding reference numerals.

<FIG> schematically illustrate an exemplary embodiment of a needle hub assembly <NUM> and a syringe <NUM> comprising such assembly <NUM> according to the present invention. Below, the presently disclosed syringe <NUM> with the needle hub assembly <NUM> will be described in general terms, where appropriate with reference to <FIG>.

The needle hub assembly <NUM> according to the presently disclosed invention is configured to cooperate with a syringe <NUM> suitable for injection of fluids in medical applications and the dosing of chemicals in non-medical applications. The needle hub assembly <NUM> is for instance suitable for injecting botulinum toxin into subcutaneous tissue.

The needle hub assembly <NUM> has a longitudinal central axis L1. The needle hub assembly may comprise a needle hub body <NUM> having a syringe connector <NUM> for receiving an attachment member <NUM> of the syringe <NUM>. The syringe connector <NUM> is provided at a first end 210a of the needle hub body <NUM>. At a second, opposing, end 210b of the needle hub body <NUM> a needle receiving portion <NUM> may be provided. The needle receiving portion <NUM> is configured to receive and hold a hypodermic needle <NUM>. The needle <NUM> extends from the needle hub body <NUM> in a direction substantially parallel to the longitudinal axis L1 of the hub assembly <NUM>. In the depicted embodiment, the needle <NUM> may for instance be a <NUM> x <NUM> needle <NUM>. Preferably, <NUM> - <NUM> needles may be received in the needle receiving portion <NUM>. A <NUM> needle <NUM> is a very thin needle with a cross sectional dimension of approximately <NUM>. Therefore, when using such needle <NUM>, the trauma to a patient during injecting the botulinum toxin into the determined tissue is relatively low. Since with a botulinum toxin treatment the patient may be subjected to multiple injections and since the injections may need to be repeated after a while due to the diminishing effect of said botulinum toxin treatment, using such a thin needle <NUM> decreases the discomfort to a patient.

The needle hub body <NUM> may be of a material with a greater hardness than the material of the syringe <NUM>. The needle hub body <NUM> may for instance be of a polycarbonate.

The syringe connector <NUM> may include a substantially conical receiving opening <NUM> as is clearly visible in <FIG>. The receiving opening <NUM> may be adapted to receive a syringe attachment member <NUM>, at least a distal end 110b thereof. A length A of said receiving opening <NUM> (see <FIG>), measured along the longitudinal axis L1, may be between <NUM>-<NUM>, in the shown embodiment approximately <NUM> +<NUM>. The attachment member <NUM> receiving opening <NUM> may comprise an entrance area <NUM>, an upper surface <NUM> and an inner circumferential wall <NUM> that extends between an entrance area perimeter 220a and an upper surface perimeter 222a. The inner circumferential wall <NUM> may taper from the entrance area <NUM> towards the upper surface <NUM> with approximately <NUM>%. Preferably, the entrance area <NUM> of the receiving opening <NUM> has, at the most proximal end 210a of the needle hub body <NUM>, a cross sectional dimension D of <NUM>-<NUM>. In the centre 222b of the upper surface <NUM>, a convex centre part <NUM> is provided that has a width W that extends from said upper surface <NUM> approximately <NUM> along the longitudinal axis L1 in a direction away from the needle <NUM>.

As is visible in <FIG>, the syringe <NUM> may include a barrel <NUM> and a plunger <NUM>. The barrel <NUM> may include an elongate tubular, e.g. cylinder jacket-shaped, body <NUM> that extends along a longitudinal axis L2 of the syringe <NUM>, between a proximal end 312a and a distal end 312b, and that defines a central bore <NUM> in which the plunger <NUM> is at least partially slidably and rotatably receivable. At its proximal end 312a, the barrel body <NUM> may be provided with two finger wings <NUM> to allow a clinician to press an extended plunger <NUM> into the bore <NUM> of the barrel <NUM> with a thumb, while supporting two fingers distally against the finger wings <NUM> in a conventional manner of syringe operation. In another, not shown exemplary embodiment, the barrel <NUM> may include a collar. The barrel <NUM> and the collar may be manufactured separately and optionally releasably connected first during assembly, or be integrally formed. Both the barrel <NUM> and the collar may be made from plastic, for instance from a polypropylene by means of injection moulding. The finger wings <NUM> may also serve to facilitate attachment of the collar to the barrel body <NUM>. At the distal end 312b of the barrel body <NUM>, the central bore <NUM> may end in a fluid port <NUM> through which fluid may be drawn into and/or ejected from the bore <NUM>. The distal end 312b of the barrel body <NUM> itself may taper into a hollow tip, which may provide the attachment member <NUM> for attaching the needle hub assembly <NUM> thereto. The attachment member <NUM> may be a Luer-Slip tip, as shown in the Figures.

The barrel body <NUM> of the syringe <NUM> shown in the Figures is opaque. In different embodiments, however, the barrel body <NUM> may be transparent to enable a clinician to visually assess the contents of the barrel bore <NUM>, for instance to confirm a state/condition or identity of a fluid contained therein. In embodiments featuring a transparent barrel body <NUM>, the barrel body <NUM> may be provided with a volume graduation, for instance in millilitres.

The plunger <NUM> may include a sealing element <NUM> and a handle <NUM>. The sealing element <NUM>, which may be made of a suitably flexible and fluid impermeable material, may be attached to a distal end 400b of the plunger <NUM>, and be dimensioned to enable slidable, sealing contact with an inner wall of the central bore <NUM> of the barrel <NUM>. The fluid port <NUM>, an inner wall of the central bore <NUM> and the sealing element <NUM> may thus delimit a portion of the central bore <NUM> that serves as a fluid chamber configured to contain a fluid to be delivered by the syringe <NUM>. The size of the fluid chamber may be varied by slidably displacing the plunger <NUM> relative to the barrel <NUM>. This way, the fluid chamber can be varied in size from nearly the entire volume of the central bore <NUM> to approximately zero.

The handle <NUM> of the plunger <NUM> may be provided at the proximal end 400a of the plunger <NUM>, and, at its proximal end 400a, provide a support surface <NUM> for a finger or thumb.

A longitudinal sliding motion of the plunger <NUM> in and relative to the barrel <NUM> may increase or decrease the volume of the fluid chamber, and thus enable aspiration or ejection of fluid into or from the barrel bore <NUM>.

The syringe connector <NUM>, the attachment member <NUM> and the sealing element <NUM> may be configured to cooperate such that, when the plunger <NUM> is completely slid into the barrel <NUM>, a space <NUM> enclosed by the syringe connector <NUM>, the attachment member <NUM> and the sealing element <NUM> may have a volume that is less than <NUM>µl. Preferably, the space <NUM> may have a volume between <NUM>µl and <NUM>µl for example approximately less than <NUM>µl. Furthermore, the distal end 400b of the plunger <NUM> has a substantially elongate shape that extends through the attachment member <NUM> such that the distal end 400b of the plunger <NUM>, in an inserted position, substantially completely occupies an inner space <NUM> of the attachment member <NUM>. Consequently, the syringe <NUM> including the needle hub assembly <NUM> provides a substantially zero dead space dosage device that enables minimizing the toxin loss that usually may occur when injecting botulinum toxin. Since the needle hub body <NUM> material, i.e. polycarbonate, may be harder than the material of the syringe <NUM>, i.e. polypropylene, disconnection of the needle hub body <NUM> from the attachment member <NUM> may be prevented. The attachment member <NUM> may have a length <NUM> of at least <NUM>, preferably of <NUM> ± <NUM>. The diameter d of the distal end 110b of the attachment member <NUM> is approximately <NUM> - <NUM>.

The syringe <NUM> may be part of a kit, for instance a sterilized kit, comprising a packaging such as a hard shell blister packaging. Such a packaging may contain a syringe <NUM> and at least one needle hub assembly <NUM> according to the described exemplary embodiment.

Claim 1:
Needle hub assembly (<NUM>) for a syringe (<NUM>), said assembly having a longitudinal axis (L1) comprising:
- a needle hub body (<NUM>) having a syringe connector (<NUM>) for receiving an attachment member (<NUM>) of a syringe (<NUM>) at a first end (210a) of the body (<NUM>) and a needle receiving portion (<NUM>) at a second opposing end (210b) of the body (<NUM>),
- a needle (<NUM>) extending from the needle receiving portion (<NUM>), wherein the syringe connector (<NUM>) comprises a substantially conical receiving opening (<NUM>) for receiving a syringe attachment member (<NUM>), at least a distal end (110b) thereof, wherein an entrance area (<NUM>) of the receiving opening (<NUM>) has a cross sectional dimension (D) of approximately <NUM> to approximately <NUM>, wherein an inner circumferential wall (<NUM>) of the receiving opening (<NUM>) that extends between an entrance area perimeter (220a) and an upper surface perimeter (222a) tapers from the entrance area (<NUM>) towards the upper surface (<NUM>) with <NUM>%, characterized in that a length (A) of said opening (<NUM>), measured along the longitudinal axis (L1), is between <NUM> and <NUM>, for instance approximately <NUM>+<NUM>.