By a News Reporter-Staff News Editor at Pharma Business Week From Alexandria, Virginia, NewsRx journalists report that a patent by the inventors Roberts, Gareth (Wrexham, GB); Owen, Sioned (Denbigh, GB); Ekman, Matthew (Macclesfiled, GB), filed on June 21, 2011, was published online on March 7, 2017 (see also Pharmaceutical Companies).
The patent's assignee for patent number 9586011 is Sanofi-Aventis Deutschland GMBH (Frankfurt am Main, DE).
News editors obtained the following quote from the background information supplied by the inventors: "Pre-filled syringes that are filled with a selected dosage of a medication are well known injection devices for administering the medication to a patient. Safety devices for covering a needle of a pre-filled syringe before and after use are also well known. Typically, these devices comprise a needle shield that is either manually moved or moved by the action of a relaxing spring to surround the needle. However, there is a need for safety devices comprising a low number of components."
As a supplement to the background information on this patent, NewsRx correspondents also obtained the inventors' summary information for this patent: "It is an object of the present invention to provide an improved safety device for a pre-filled syringe.
"It is a further object of the invention to provide an improved injection device comprising a pre-filled syringe that is safe to handle and in particular prevents accidental needle pricks.
"The object is achieved by a safety device according to claim 1 and by an injection device according to claim 18.
"Preferred embodiments are subject of the dependent claims.
"In the context of this invention, the terms distal and proximal are defined from the point of view of a person performing an injection. Consequently, a distal direction refers to a direction pointing towards the body of a patient receiving an injection and a distal end defines an end of an element that is directed towards the body of the patient. Respectively, the proximal end of an element or the proximal direction is directed away from the body of the patient receiving the injection and opposite to the distal end or distal direction.
"According to the invention, a safety device for a pre-filled syringe comprises a hollow support body to retain the pre-filled syringe therein, a hollow needle shield that is slidable relative to the support body and guiding means for guiding the movement of the needle shield relative to the support body. The guiding means comprise a deflectable flexible arm, a guide pin and a guide track. The deflectable flexible arm extends essentially parallel to a central axis of the safety device. The guide pin extends radially from the flexible arm. The guide track guides the guide pin within and along the guide track when the needle shield is slid relative to the support body.
"The guide pin is moved within and along the guide track when the needle shield is slid relative to the support body to cover and/or to expose in particular a hypodermic needle of a pre-filled syringe inserted into the support body of the safety device. As the flexible arm is deflectable in a lateral direction, a relative rotation of any external parts like the needle shield and the support body is unnecessary to guide the guide pin along the guide track. Especially when external parts of the safety device abut the skin of a patient during the injection, friction between these rotating external parts and the skin of the patient is uncomfortable and may even cause pain to the patient, in particular while the hypodermic needle still penetrates the skin. The safety device thus allows for a safe and convenient injection of a medication.
"The guiding means of the safety device comprise a longitudinal tongue that is received in a longitudinal groove when the needle shield is moved with respect to the support body in a distal direction, whereby a relative rotation of the needle shield and the support body is prevented. This anti-rotational guiding means ensures the proper interaction of the guide pin with the guide track when the needle shield and the support body is moved axially displaced relative to each other.
"The flexible arm is connected to one of the needle shield or the support body. The guide track is formed into the other of the support body or the guide track. Therefore, it is within the scope of the present invention that the safety device comprises a support body with a guide track and a needle shield with a flexible arm, or alternatively, that the flexible arm is connected to the support body and a guide track is formed into the needle shield.
"Preferably, the flexible arm is integrally formed to the needle shield or to the support body. The safety device comprises only a small number of parts that are cost-efficiently mass-produced allowing the safety device to be used as a single-use disposable device that provides needle safety for disposable pre-filled syringes.
"The flexible arm is deflectable and energizable by the action of a relaxing spring means, e.g. a compression spring, biasing the needle shield in the retracted position. Thus, no additional effort is required from the user performing the injection to energize the flexible arm.
"According to a possible embodiment, the guide pin is located in an intermediate position in proximity of a proximal end of the guide track when the needle shield is in a retracted position and in an end position in proximity of a distal end of the guide track when the needle shield is an advanced position.
"The needle shield is substantially received in the support body in the retracted position and protrudes the distal end of the support body in the advanced position. The movement of the guide pin within and along the guide track controls the extension and/or retraction of the needle shield allowing for a safe injection.
"Alternatively, the substantial cylindrical needle shield comprises a radial diameter that is sized to substantially receive the support body in the retracted position. In this alternative embodiment the support body slides into the needle shield when the needle shield is moved from the advanced to the retracted position.
"In a possible embodiment of the invention, the movement of the needle shield is controlled in a way as to hide the hypodermic needle from the view of a user throughout the injection. This reduces the fear of performing in particular self-administered subcutaneous injections that patients suffering from diabetes frequently have to carry out.
"The guide pin in the end position is prevented from moving in a proximal direction by an interaction between the guide track and the guide pin, so that the needle shield is locked in the advanced position. The safety device is rendered non-reusable after the first use, whereby a further interaction or attention of the user is not required.
"The guide pin in the start position, in the end position and in the intermediate position is non-biased in a lateral direction perpendicular to the central axis. The flexible arm is deflected to bias the guide pin during use of the safety device. The safety device is stored with the guide pin retained in the start position, wherein the flexible arm is not stressed and in an equilibrium position. This avoids material fatigue and associated mechanism failure even after prolonged periods of storage.
"The guide pin in the end position is in an equilibrium position locking the needle shield in the advanced position and preventing re-usage of the safety device. As the guide pin is non-biased in the lateral direction in the intermediate position, occurring friction between the guide pin and the guide track is minimized during the injection stroke performed by the user, so that the injection stroke can be carried out with minimal effort.
"The flexible arm is deflected to bias the guide pin in the lateral direction when the guide pin moves along the guide track from the intermediate position towards the end position. As the flexible arm is typically made from a resilient plastics material that is prone to fatigue of material, it is advantageous to deflect and energize the flexible arm during use of the safety device, so that the shelf-life of the safety device is extended.
"According to a possible embodiment of the invention, the needle shield protrudes the support body in an initial position and the spring mean is in a partially energized state when the needle shield is in the initial position. As the safety device is stored with the needle shield in the initial position, fatigue of material of the spring mean is avoided by only partially energizing the spring mean. This allows for a reliable use of the safety device even after prolonged periods of storage.
"According to a possible embodiment, the needle shield is made from an opaque plastics material. The hypodermic needle is hidden from the view of the patient before the injection by the needle shield that is retained in the initial position. This eases a possible fear of needles of the patient. The safety device is thus particularly suited for performing self-administered injections.
"According to an alternative embodiment, the needle shield is made from a transparent plastics material. A healthcare professional that uses the safety device thus can visually confirm the correct placement of the hypodermic needle penetrating the skin of the patient, even when the hypodermic needle is surrounded by the needle shield.
"As the safety device is both suited for self-administered injections and injections carried out by a healthcare professional, the person referred to as the user or the patient may be one and the same person.
"In a possible embodiment of the invention, the needle shield of the safety device is retained in the initial position prior to use by a resilient flexing gate element releasably retaining the guide pin in a start position located between the distal and the proximal end of the guide track. The flexing gate element serves as a simple means to releasably retain the needle shield connected to the guide pin in the initial position, whereas the needle shield protrudes the distal end of the support body to surround the hypodermic needle of the pre-filled syringe before the injection.
"According to the same embodiment of the invention, the resilient flexing gate element guides the movement of the guide pin within the guide track, so that the movement of the needle shield relative to the support body is controlled in a manner that avoids a relative rotation of needle shield and support body.
"According to the same embodiment, the flexing gate element is deflectable in a lateral direction as to allow the guide pin to move proximally from the start to the intermediate position. In particular, the flexing gate element is integrally formed into the support body and establishes a section of narrowed width that the guide pin has to pass to leave the start position and to activate the needle safety features of the safety device. A user typically applies a force to the needle shield in a distal direction to activate the safety features, so that the guide pin passes the section of narrowed width, whereby the flexing gate element is laterally deflected. Thus, an inadvertent activation of the needle safety features is prevented by the flexing gate element that retains the guide pin in the start position in particular during transportation of the safety device prior to use.
"The flexing gate element of the same embodiment comprises a sloped section that guides the movement of the guide pin along a section of the guide track from the intermediate to the end position and prevents the guide pin from re-entering the start position. The safety device is non-reusable after a single injection has been performed and thus adapted to be used in combination with a disposable pre-filled syringe.
"According to another embodiment of the invention, the needle shield further comprises at least one radial outwardly protruding retaining catch that can be engaged by a release flap formed into the support body. The needle shield is releasably retained within the support body by the release flap and the retaining catch in the retracted position. The release flap is hinged to the support body. The release flap is engaged by an interior surface of the outer body at the end of an injection stroke, whereas the release flap presses the retaining catch inwards to release the needle shield. This mechanism prevents an unintended early release of the needle shield and makes sure that the medication has been fully delivered before the needle shield is released.
"In yet another embodiment of the invention, the outer body comprises an inward projection that abuts the guide pin in the intermediate position to retain the needle shield in the retracted position. This simple mechanism allows for a secure retention of the needle shield in the retracted position.
"According to the same embodiment, the guide pin and the inward projection comprise a triangular cross-section, so that upon releasing the needle shield from being retained in the retracted position, the guide pin is redirected in the lateral direction and guided within and along the guide track. This minimizes friction between the guide pin, the guide track and the inward projection allowing for a smooth use of the safety device.
"The inward projection of the same embodiment moves along a section of the guide track thereby releasing the needle shield from being retained in the retracted position. The mechanism for both retaining and releasing the needle shield is integrated in existing parts having additional functionality. The safety device has a low part count that can be cost-efficiently produced.
"An injection device comprises a pre-filled syringe retained in the support body of the safety device. The pre-filled syringe comprises a hypodermic needle attached to a distal end of the pre-filled syringe, a barrel with an inner cavity in fluid communication with the hypodermic needle and a piston fluid-tightly sealing a proximal end of the inner cavity. The piston is movable by actuating a piston rod protruding a proximal end of the barrel. The pre-filled syringe is retained within the support body of the safety device, so that the hypodermic needle protrudes the distal end of the support body. The hypodermic needle of the injection device is surrounded by the needle shield in the initial position and/or in the advanced position and the hypodermic needle is exposed when the needle shield is in the retracted position. The injection device comprising the pre-filled syringe and the safety device combines the aforementioned advantages and avoids inadvertent needle sticks before, during and after an injection delivering the medication beneath the skin of patient.
"The injection device is particularly suited for self-administered subcutaneous and intramuscular injections.
"Details of the present invention are described hereinafter. However, it should be understood that the detailed description and the specific examples indicate possible embodiments of the invention and are given by way of illustration only. Various changes and modifications of the illustrated embodiments within the spirit and scope of the invention are appreciated by those skilled in the art."
For additional information on this patent, see: Roberts, Gareth; Owen, Sioned; Ekman, Matthew. Safety Device for a Pre-Filled Syringe and Injection Device. U.S. Patent Number 9586011, filed June 21, 2011, and published online on March 7, 2017. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=9586011.PN.&OS=PN/9586011RS=PN/9586011
Keywords for this news article include: Pharmaceutical Companies, Sanofi-Aventis Deutschland GMBH.
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