The invention relates to a method and device for injecting a drug.
In the art, a variety of methods exist as alternatives for drug delivery via needle-based and also nozzle-based (i.e. needle-free or jet) injection. Commercially available liquid jet injectors use compressed gas or spring to create high pressure jets. The current techniques are efficient; however, there are some limitations.
In “Er:YAG laser pulse for small-dose splashback-free microjet transdermal drug delivery” Mi-ae Park et al. Optics letters/Vol. 37, No. 18/Sep. 15, 2012, a method is described wherein a fluid jet is formed by a membrane that acts in response to a vapour bubble by laser pulsing. The fluid jet ejects from a nozzle, at sufficient velocity needed to penetrate the skin. The disclosure describes that this type of delivery eliminates needle waste and provides a favourable alternative for needle-phobic patients. However, this type of jet forming is inadequate for a variety of drugs, inter alia since a nozzle is used for providing a fluid jet. The current invention aims at providing a device and delivery method, wherein the advantages of micro dose jet delivery can be attained wherein a wider range of applications is possible.
To this end, it is proposed to provide a device for drug supply, the device comprising:
The laser spot used for LIFT could have a diameter ranging from 5 microns-5 mm. The wavelength of the pulsed laser could be in the range of 200 nm-1200 nm (and could be of nanosecond or picosecond or femtosecond type). The fluence of the laser could be in the range of 10 mJ/cm2-10 J/cm2.
The light spot is aimed on a transparent carrier substrate 70, for example, a transparent carrier such as glass, film or tape; a quartz glass for a 248 nm KrF excimer and PET film or Soda Lime Glass for a 355 nm Nd:YAG laser. On the substrate 70 a thin layer of a dynamic release layer is applied. This may be a thin layer (80 to 200 nm) of Triazene polymer that ejects, under the influence of the light beam 74 a propelling gas for transfer of the drug from the drug layer. Different dynamic release layer materials could potentially be used such as polymers with metallic nanoparticles, or a combination of triazene polymer layer and thin metal layer. Adjacent this layer 152, a drug layer 151 is provided with an active substance. In the example, the dynamic release layer 152 is formed by a triazene layer of about 100 nm thickness which functions as a sacrificial dynamic release layer (DRL), and comprises a polymer that, when photoactivated decomposes into nitrogen and other organic volatile gases 1521. A typical peak absorption is found at 290-330 nm and the ablation threshold: 22-32 mJ/cm2 at 308-248 nm is quite low so that the layer 151 is neither thermally loaded or optically degraded and remains intact after transfer, in such a way that the active drug substance 1511 is preserved. For example, the laser beam may be restricted in timing and energy. Accordingly a desired property of the drug substance can be retained during transfer by impinging the laser beam on the dynamic release layer 152 adjacent to the drug layer 151; in order to supply a predetermined quantity of drug to the skin or tissue 100.
To illustrate the general applicability of the drug delivery method solids, fluids or even highly viscous substances may be transferred, for example, with a viscosity of 1-180 Pa.s. The layer 151 may be provided as homogenous layer of 20-30 micron, in particular, 25 micron thick provided on the dynamic release layer 152. The thickness is controlled to be around 25 um or 50 um but could be of any thickness. The donor drugs may be provided in a cartridge 72 that is held at a distance of about 1-5 millimeter away from the skin or tissue by spacers 30 that function as a placement provision arranged for distancing the carrier from the skin or tissue.
The device further comprises a transmission part 71 that transmits the laser beam 74 to a suitable spot on the substrate 70. The transmission part, in the example, may comprise a beam deflector 71 that is controlled to target a virginal area by deflection of said beam 74 over the donor film. The laser beam is (optionally) scanned over the substrate thereby efficiently using all area containing the drug substance. The scanning may be done using a MEMS mirror. If the substrate width is almost the same as the laser spot size, then beam scanning may not be necessary.
Scanning the laser beam 74 can typically be arranged by a MEMS scanning xyz stage for scanning the laser beam over the donor cartridge 72. While a transmission part 71 may be formed by a single aperture, typically, the transmission part may comprise a variety of optical elements, for instance, a shutter, beam expander 73 and/or focusing elements to change the spot size of the beam at the location where it impinges on the carrier 70. The transmission part may be a fast beam modulator 71 (galvano mirror, polygon mirror, acousto-optic or electro-optic modulator etc.) may provide a scanning movement of the laser beam in a first direction. The modulator may be controlled in a feed forward process. Optionally, a main beam is split into about 2-20 sub beams.
The device 20 can be designed as a handheld device, for example, including a pistol grip (not shown), and the light source included in the holder. The device 20 further comprises a control mechanism, for example, a microprocessor controller 24 arranged on a wiring board. The controller is connected via connection lines 241 to various items that function for moving the light beam and/or the carrier relative to each other, in order to target a virginal area of the carrier 70 for the light beam. Such a virginal area may be described as an area that is not targeted previously, or at least prepared in a way that a dynamic release layer 152 can function to eject, under the influence of the light beam 74, a propelling gas 1521 for transfer of the drug from the drug layer 151. The controller 24 further functions to have the light beam imping, via the transmission part 71 on the carrier 70; in such a way that the carrier is activated, in the example via the release layer 152, to eject a distinct quantity of drug transferred (50), by light induced propulsion, in normal direction from the carrier from the drug layer to the skin or tissue. The controller 24 may function as a dosage counter that can be preprogrammed or even hardwired, and that is arranged to repeat the steps of moving and impinging the light beam in an computer-controlled way, in order to supply a predetermined quantity of drug to the skin or tissue 100. The controller 24 preferably has a dosage control feature that registers the effective medicinal area available, so that efficiently all drug substance may be used.
This is especially useful for viscous types of substances, in a viscosity range of 100-180 Pa.s.
In
A laser repetition rate may be as high as 60-600 kHz. Depending on the laser repetition rate, a donor film refreshment rate may be provided by the carrier transport mechanism at a velocity ranging at from 100 micron/s-0.1 m/s. In order to provide a virginal area a start-stop mechanism may be provided, where a laser beam is scanned over a donor material layer 151 in stop condition, and wherein the material layer is transported in order to provide a next virginal area.
The delivery device may also be moved by a motorized stage (not disclosed) that can be moved in accordance with alignment control means that align the delivery device relative to an injection point.
Other variations to the disclosed embodiments can be understood and by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. A single unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.
Number | Date | Country | Kind |
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13154807.5 | Feb 2013 | EP | regional |
Filing Document | Filing Date | Country | Kind |
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PCT/NL2014/050078 | 2/10/2014 | WO | 00 |