FIELD

The invention relates to injectors for medicaments. Specifically, to injectors configured to inject a medicament from a syringe.

BACKGROUND

Many methods are used to inject medicaments into a target site. These include syringes, auto-injectors, and drug pumps. The medicament can be injected at a variety of depths. For example, the medicament can be injected into the epidermis, the dermis, the subcutaneous region, or into the muscles (intramuscular). Some of these devices are specifically intended for at home use by a patient. These devices can be used to deliver a variety of medicaments. For example, the injectors can be used for the delivery of epinephrine to patients who are at risk of anaphylaxis. Such devices include the ANAPEN™ injector sold by Lincoln Medical Ltd. of the United Kingdom and the EPIPEN® injector sold by Mylan Inc. of Pennsylvania.

Many injectors use powerful springs to drive a plunger rod into a pre-filled syringe and inject the medicament into the tissue while pushing the injector into the side of the leg or other body location. Some of these injectors have the advantage of shielding the needle before and/or after use, thereby benefiting patients who have a fear of needles. Present injectors can contain more than twenty-six parts and be complicated to assemble due to the amount and complexity of the parts, which results in high prices to the user. The additional parts also increase the chance of failure of these complex devices.

In some applications, such as, for example, biologics, medicament is provided in a lyophilized form and is mixed with a diluent prior to injection to reconstitute the medicament. In such applications, the medicament may be provided in a vial or in a dual-chamber syringe or cartridge. Storage in the lyophilized form may increase the shelf life and/or efficacy of the medicament. However, the need to mix the medicament with the diluent introduces further steps and complications for the user and increases the risk of user error.

SUMMARY

In one aspect, an injector for delivering medicament includes a first sleeve defining a longitudinal axis, a medicament container, and a locking tab. The medicament container is at least partially disposed within the first sleeve and configured for axial translation with respect to the first sleeve along the longitudinal axis. The medicament container includes a barrel, a needle mounted to a distal end of the barrel, a seal slidably mounted in the barrel, and a plunger rod. The locking tab extends through an aperture in the first sleeve and is in contact with or adjacent to a portion of the medicament container such that the locking tab restricts translation of the barrel with respect to the first sleeve along the longitudinal axis. The locking tab is configured to be movable to a second position in which the locking tab does not restrict translation of the barrel.

In another aspect, an injector for delivering medicament includes a first sleeve defining a longitudinal axis, a second sleeve, a medicament container, a locking tab, and a pull tab. The second sleeve extends from the first sleeve such that the second sleeve is configured to translate with respect to the first sleeve along the longitudinal axis. The medicament container is at least partially disposed within the first sleeve and is configured for axial translation with respect to the first sleeve along the longitudinal axis. The medicament container includes a barrel, a needle mounted to a distal end of the barrel, a seal slidably mounted in the barrel, and a plunger rod. The locking tab restricts translation of the barrel with respect to the first sleeve along the longitudinal axis. The pull tab covers a distal aperture of the second sleeve. The locking tab is coupled to the pull tab such that the locking tab is removable using the pull tab.

In another aspect, a method of injecting medicament includes providing an injector. The injector includes a first sleeve defining a longitudinal axis, a medicament container, and a locking tab. The medicament container is at least partially disposed within the first sleeve and is configured for axial translation with respect to the first sleeve along the longitudinal axis. The medicament container includes a barrel, a needle mounted to a distal end of the barrel, a seal slidably mounted in the barrel, and a plunger rod. The locking tab restricts translation of the barrel with respect to the first sleeve. The method further includes depressing the plunger rod of the medicament container to mix a diluent with a lyophilized substance within the barrel of the medicament container. The method further includes disengaging the locking tab from the medicament container. The method further includes placing a distal end of the injector against a target site. The method further includes depressing the plunger rod to deliver the mixed diluent and lyophilized substance.

