A drug-delivering catheter

Abstract

A drug-delivering catheter is disclosed, suitable for delivering liquid drugs to target anatomical sites, such as blood vessel walls. The device may be a standard or balloon catheter and features at least one nozzle or injector—optionally with a needle—positioned on the catheter tube or balloon component. Fluid communication is established via apertures or perforations, with each nozzle configured to promote laminar flow and facilitate precise drug delivery across biological barriers. Embodiments include contiguous strips of nozzles, individually discrete nozzles, or outwardly biased arms. The device may further comprise a protective sheath, pleated balloon envelope, dedicated drug delivery passages, and radio-opaque markers. Independent control of balloon inflation and drug delivery is enabled, optimizing therapeutic outcomes while minimizing tissue damage and drug waste. The invention addresses challenges in targeted, controlled, and safe intravascular drug administration.

Description

A DRUG-DELIVERING CATHETERFIELD OF THE INVENTION

[0001] This invention relates to a catheter, either a balloon catheter or a standard catheter, which is configured to deliver a drug to a target anatomical site like, for example, walls of blood vessels.BACKGROUND TO THE INVENTION

[0002] Balloon catheters are widely utilised in various medical applications, serving diagnostic and therapeutic functions. Cardiology is essential for coronary angioplasty and stent placement, while neurovascular procedures are used for intracranial vessel dilation and embolic coil remodelling. They also play a critical role in structural heart interventions, valve preparation, and implant deployment. Peripheral vascular treatments, including deep vein thrombosis and venous stenting, rely on balloon catheters, which are also used in gastrointestinal and pulmonary medicine to treat strictures and stenoses. Additionally, balloon catheters have applications in ENT and other specialised procedures.

[0003] Certain balloon or standard catheters (hereinafter collectively referred to as “catheters”) are further enhanced to deliver drugs directly to targeted sites within the body, thereby adding a therapeutic dimension to their use.

[0004] Catheters designed to deliver drugs to specific areas, such as the walls of veins, represent a significant advancement in interventional therapy. Regarding balloon catheters, these Integrate the mechanical function of balloondilation with localised drug delivery, improving therapeutic outcomes. However, challenges arise in the design and execution of these drug-delivery systems, particularly those incorporating microneedles. The microneedles must precisely penetrate the vascular wall to release the drug effectively, all while minimising tissue damage. Ensuring consistent, controlled, and targeted drug delivery is another significant challenge. The success of such systems depends on factors such as catheter design, inflation pressure, needle penetration depth, and the compatibility of the drug with the catheter material. Thus, further development is required to optimise these systems for reliable, safe, and effective drug delivery.

[0005] The invention at least partially addresses the aforementioned problems.SUMMARY OF INVENTION

[0008] The invention provides a medical device, specifically a catheter, designed for the delivery of a liquid drug within the human body. The device includes at least one nozzle or injector — optionally with a needle — positioned either on the catheter itself or, in the case of a balloon catheter, on the inflatable balloon component. In all cases, the nozzle or injector is configured to deliver the liquid drug beyond or across a biological barrier, such as the endothelial layer lining the inner surface of a blood vessel or artery.

[0009] In one aspect, the invention provides a drug-delivering catheter comprising:a catheter tube including a first passage;at least one aperture formed in the catheter tube that provides fluid communication between the first passage and the exterior of the catheter; and a nozzle sealingly engaged with the at least one aperture, the nozzle having a body that defines a flow channel with an inlet and an outlet, the flow channel being configured to promote laminar flow of a fluid from the first passage to the outlet.

[0010] The first passage may comprise at least one of an inflation passage and a drug delivery passage.

[0011] The catheter tube comprises a plurality of outwardly biased arms, each arm having a portion of the first passage extending therethrough and including at least one aperture providing fluid communication between the first passage and the exterior of the catheter.

[0012] The drug-delivering catheter may comprise a balloon module which is disposed radially inward of the outwardly biased arms, the catheter tube further comprising a second passage in fluid communication with the interior of the balloon module, wherein inflation of the balloon module via the second passage causes the outwardly biased arms and their associated apertures to move into contact with the target anatomy.

[0013] The drug-delivering catheter may include a plurality of apertures with a plurality of nozzles, each nozzle engaged with a respective aperture.

[0014] The plurality of nozzles may be contiguous and formed as part of a strip, with the strip sealingly engaged with the catheter tube and positioned such that each aperture aligns with the flow channel of a corresponding nozzle.

[0015] In a second aspect, the invention provides a drug-delivering balloon catheter including:a catheter tube having an inflation passage with an exit port:a balloon component including a flexible envelope, the envelope engaging the catheter tube at a proximal and a distal neck, the envelope surrounding the exit port to define an inflatable volume, the inflatable volume being inflatable by an inflow of inflation fluid through the exit port:at least one perforation formed in the flexible envelope; and a nozzle sealingly engaged with the at least one perforation, the nozzle having a body that defines a flow channel with an inlet and an outlet, the flow channel being configured to promote laminar flow of a fluid from the inflatable volume to the outlet.

[0016] The drug-delivering balloon catheter may include a plurality of perforations with a plurality of nozzles, each nozzle engaged with a respective perforation.

[0017] The plurality of nozzles may be contiguous and formed as part of a strip, with the strip sealingly engaged with the envelope and positioned such that each perforation aligns with the flow channel of a corresponding nozzle.

[0018] The perforations may be pre-formed apertures which penetrate the envelope, or they may be latent perforations (score lines or etchings) configured to open when the pressure within the inflatable volume reaches a threshold.

[0019] The pre-formed perforations may be laser-cut or punched into the envelope. The latent perforations may be formed in the envelope by any suitable means, such as scribing, scoring or etching.

[0020] The strip may include an inner side and an outer side, with the outer side configured to contact the vessel wall when the balloon component is inflated within a vessel. The inner side of the strip engages the envelope and is arranged to extend longitudinally within a working region of the balloon component.

[0021] In a third aspect, the invention provides a drug-delivering balloon catheter including:a catheter tube having an inflation passage with an exit port;a balloon component comprising a flexible envelope, the envelope engaging the catheter tube at a proximal and a distal neck, the envelope surrounding the exit port to define an inflatable volume, the inflatable volume being inflatable by an inflow of inflation fluid through the exit port;a nozzle sealingly engaged with the envelope, the nozzle having a body that defines a flow channel with an inlet and an outlet;at least one piercing element located within the flow channel and extending from the roof of the channel toward the flexible envelope, the spike configured to rupture the envelope upon inflation of the balloon component, thereby allowing fluid to flow from the inflatable volume into the flow channel;wherein the flow channel is configured to promote laminar flow of a fluid from the inflatable volume to the outlet.

[0022] Preferably the nozzle comprises a pair of piercing elements.

[0023] The drug-delivering balloon catheter may include a plurality of nozzles.

[0024] The plurality of nozzles may be contiguous and formed as part of a strip, with the strip sealingly engaged with the envelope.

[0025] The strip may include an inner side and an outer side, with the outer side configured to contact the vessel wall when the balloon component is inflated within a vessel. The inner side of the strip engages the envelope and is arranged to extend longitudinally within a working region of the balloon component.

[0026] The following optional features may apply to the second and third aspects to the invention.

[0027] The inflation fluid may include a drug.

[0028] The outer surface of the strip may comprise a plurality of raised portions, with recessed portions positioned between adjacent raised portions.

[0029] Each nozzle may include a needle extending from its outlet to form a projection, with each nozzle positioned within a recessed portion aligned with a corresponding flow channel.

[0030] The height of the needle may be selected based on the target drug delivery site and the depth of tissue to be pierced.

[0031] The drug-delivering balloon catheter may include a plurality of strips.

[0032] The strips may be uniformly radially spaced around the working region of the balloon component.

[0033] The flexible envelope may be folded in the longitudinal direction to form a plurality of pleats, each with an outer surface and an inner folded surface.

[0034] Each strip may be engaged to the outer surface of each pleat.

[0035] The drug-delivering balloon catheter may include a protective sheath that covers the balloon module, extending at least the full length of the strips.

[0036] The sheath may be made from one or more of the following materials: polyether block amide (PEBAX), thermoplastic polyurethane (TPU), PTFE, and FEP.

[0037] The sheath may extend to the proximal end of the catheter tube and connect to a sheath-actuator or catheter handle, which is actuatable to retract the sheath.

[0038] The catheter tube may include a guidewire lumen and a guidewire within the lumen.

[0039] The guideline may include radio-opaque marker bands positioned axially to align with the proximal and distal ends of the working region.BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The invention is further described by way of examples, with reference to the accompanying drawings in which:Figure 1 is an isometric view of a drug-delivering balloon catheter in accordance with a first embodiment of the invention,Figure 2 is a view in the longitudinal section of the first embodiment of Figure 1,Figure 3 is an insert providing a detailed view of the region highlighted in Figure 2,Figure 4 is an isometric view from below of a strip that is engaged to a balloon component of the balloon catheter,Figure 5 is an isometric view of a drug-delivering balloon catheter in accordance with a second embodiment of the invention,Figure 6 is a partial isometric view of Figure 5,Figure 7 is a cross-sectional view of the balloon catheter from Figures 5 and 6, taken along the circumferential dotted line labelled 7 in Figure 6,Figure 8 is a cross-sectional view of the balloon catheter from Figures 5 and 6, taken along the circumferential dotted line labelled 8 in Figure 6;Figure 9 schematically illustrates a drug-delivering catheter in accordance with another aspect of the invention.Figures 10 to 12 schematically depict alternative internal configurations of the drug-delivering catheter shown in Figure 9;Figures 13 and 15 are isometric views of a drug-delivering balloon catheter embodiment featuring individually separate drug-delivery nozzle outlets;Figure 14 is an isometric view of a drug-delivering catheter with a plurality of outwardly biased arms;Figures 16 and 19 are a sectional view through an individually separate nozzle, and Figure 17 illustrates this nozzle engaged with a perforation formed through a balloon component of a drug-delivering balloon catheter;Figure 18 illustrates an alternative, with a nozzle internally engaged with a perforation formed through a balloon component of a drug-delivering balloon catheter;Figure 20 is a sectional view of a contiguous array of nozzles formed as a strip; Figures 21 and 22 are sectional views of nozzles in which an underlying frangible membrane, as part of a balloon component of a drug-delivering balloon catheter, has been ruptured;Figure 23 schematically and isometrically illustrates a nozzle with blades adapted to penetrate the underlying frangible membrane;Figure 24 is a sectional view of the nozzle of Figure 23;Figures 25 and 26 are isometric views of a drug-delivering catheter with an outwardly biasing section comprising a plurality of biasing arms, shown in the deployed and collapsed state, respectively; andFigures 27, 27A and 28 are isometric views of a drug-delivery catheter featuring a dedicated drug-delivery line in fluid communication with a nozzle, and an inflation balloon supplied via a separate inflation lumen.DESCRIPTION OF PREFERRED EMBODIMENT

[0041] Referring to Figures 1 and 2 and a first embodiment, the drug-delivering balloon catheter 10.1 includes a catheter tube 12 having an inflation lumen 14 with an exit port 16.

[0042] The catheter tube has a standard configuration that allows for trackability over a guidewire 62 (see Figure 13) and inflation of a balloon component 18. This configuration may be either coaxial or multi-lumen (see Figures 10 to 14, which will be described below), with the inflation lumen being one of the multiple lumens. It also includes a Luer fitting 64 (see Figure 9) at the proximal end for connection to a syringe for inflation and guidewire insertion, as is customary.

[0043] On the catheter tube 12, the balloon catheter 10 includes a balloon component 18, which has a flexible envelope 20 that engages the catheter tube at a proximal and a distal neck (22, 24) to surround the exit port 16 and define an inflatable volume 26. The inflatable volume 26 is inflatable by an inflow of an inflation fluid through the exit port.

[0044] The flexible envelope is made of one or more of the following: a thermoplastic polyurethane (TPU), a thermoplastic elastomer (TPE), polyether block amide (PEBAX), polyethene terephthalate (PET) and Nylon 12 (PA12).

[0045] When the balloon is inflated, the balloon component 18 forms a cylindrical working region 28 (Fig. 1) between the proximal and distal cones (30.1, 30.2).

[0046] In this first embodiment, the balloon catheter 10 1 includes a plurality of strips designated 32.1, 32.2..., 32. N, each having an inner side 33 and an outer side 35 (see Figure 4). The inner side of each strip is bonded to the exterior surface of the envelope 20 in longitudinal extension within the working region 28 of the balloon component.

[0047] In an embodiment not illustrated, the strips can be connected to form a frame.

[0048] Each strip 32 includes a continuous series of nozzles, identified as 34.1 to 34.5. In this configuration, each nozzle — integrated within the strip — features a flow channel 36 that extends from an inlet 38 to an outlet 41, forming a passage through the strip. These structural characteristics are also found in other nozzle embodiments, such as the individually discrete nozzle design shown in Figure 16.

[0049] Each strip 32 is positioned on the balloon component 18 such that the flow channel 36 of each nozzle 34 aligns with a corresponding perforation 40, enabling fluid communication between the inflatable volume 26 and the exterior of the balloon catheter.

[0050] Each nozzle 34 maybe designed with an outlet extension that forms a micro-needle 42, resulting in a protruding structure. The height of these microneedles can be adjusted based on the specific drug intended for delivery via the balloon catheter 10 and / or the anatomical features of the target delivery site.

[0051] Furthermore, each strip includes a series of ramps 46.1 to 46.6, with recesses 48.1 to 48.5 formed between adjacent ramps (see Figure 5). Within recess 48, the nozzles 34, with their respective microneedles 42, are positioned.

[0052] An adhesive ring or seal 44 is provided on the inner side of the strip, around each inlet 38. This ring provides a means for bonding the strip to the envelope and ensuring a pressure seal between the outlet and the balloon, preventing liquid from leaking past the inlet. The sealing ring may consist of an adhesive bond, thermal bond, or mechanical seal between the balloon substrate and the strip substrate.

[0053] In an alternative configuration, illustrated in Figures 13 and 15, the drug¬ delivering balloon catheter 10.3 does not include strips. Instead, the device features one (Figure 15) or more (Figure 13) perforations (40.1, 40.2, 40.3), with each perforation equipped with a separate, discrete nozzle 34 (see Fig. 4), as described below. Each perforation and its associated nozzle may be connected to an individual inflation lumen, thereby enabling the delivery of different fluids, with each fluid containing a distinct medication.

[0054] The nozzle 34 may be sealingly engaged with a corresponding perforation, either projecting outward as shown in Figure 17 or inward as depicted in Figure 18.

[0055] The balloon component 18 features a plurality of perforations. Figure 3 illustrates only one of these perforations, designated 40. The perforations can be pre-formed to penetrate the flexible envelope 20, or they can be latentperforations, configured to rupture (as illustrated in Figures 21 and 22) and open when a pressure within the inflatable volume 26 reaches a threshold.

[0056] Whether incorporated as part of a strip or as a standalone component, the nozzle 34 may have a configuration as depicted in Figures 23 and 24. This particular nozzle features an ovoid body 60 and includes, within its flow channel 36, a pair of bladed spikes (64.1, 64.2) that extend downward from the roof of the channel toward the flexible membrane 20 of the balloon component 18, to which the nozzle is sealingly attached. Upon inflation of the balloon component, the expanding membrane is forced into contact with the spikes, causing a tear or rupture in the membrane. This rupture initiates in the longitudinal direction of the balloon catheter, allowing fluid to pass through the nozzle and reach the target site.

[0057] In another embodiment of the drug-delivering balloon catheter 10.2, illustrated in Figures 5 and 6, the flexible envelope 20 of the balloon component 18 is folded into a plurality of longitudinally extending pleats, 50.1 to 50.5 (see Figures 7, which best illustrate this feature), each formed with an inner folded portion 52 and an outer portion 54.

[0058] In this example, the strips 32 are attached to the outer surface. With this arrangement, when the balloon component is folded for insertion, the sharp tips of the micro-needles 42 point outward, away from the envelope 20. This orientation helps prevent damage to the balloon component, which is made from a thin-walled polymer material.

[0059] In either of these two embodiments, the balloon catheter may include a protective sheath 56 (shown covering the cross sections of Figures 7 and 8 but not illustrated in Figure 6 for ease of illustration) that covers the balloon component 18, extending along at least the full length of the strips 32. This sheath prevents the needles from snagging as the balloon module is advanced to the target site. Once the balloon module reaches the target site, the sheath can be withdrawn by any suitable means, allowing the balloon to be inflated.

[0060] The ramps 46 on the strips 32 create a clearance height that protects the tips of the needles from potential damage by the sheath during retraction.

[0061] When the balloon component 18 is appropriately positioned, often indicated by radio-opaque marker bands (shown in Figure 28, designated 68) placed within the balloon and on the outer surface of a guidewire lumen (shown in Figure 27, designated 70), it is inflated with fluid through the inflation lumen 14.

[0062] As previously noted, the drug-delivering balloon catheter is not restricted to using nozzles 34 equipped with micro-needles. Nozzles without needles can deliver drug-containing inflation fluid directly to the target anatomy. This invention allows for precise drug delivery to specific anatomical sites, such as a diseased blood vessel adjacent to the catheter, by generating a high-pressure fluid jet through the nozzle configuration described below.

[0063] In other embodiments of the invention, the device may omit the balloon module and consist solely of a catheter. In these embodiments, the invention provides a drug-delivering catheter 10.4 comprising: a catheter tube 12 with aninflation passage 14, at least one aperture 40 (analogous to the perforations in the balloon catheter embodiments) in the catheter wall that allows fluid communication between the inflation passage and the catheter's exterior, and a nozzle 34 sealingly engaged with the aperture.

[0064] Figures 10 to 12 illustrate various internal configurations of the catheter tube 12. In Figure 10, the catheter tube features both an inflation passage and a guidewire lumen 57. Figure 11 shows catheter tube 12, which additionally features a pair of diametrically opposed steering wire lumens (58.1 and 58.2). A simplified configuration is shown in Figure 12, where catheter tube has a single passage that serves as both the inflation passage and the guidewire lumen.

[0065] The nozzle 34, which sealingly engages either a perforation 40 in the balloon (as shown in the balloon catheter variant in Figure 15) or an aperture 40 in the catheter tube (in the non-balloon variant), includes a body 60 that defines a flow channel 36 between the inlet 38 and the outlet 41. The flow channel is engineered with a smooth, uniform internal surface and a length-to- diameter ratio optimized to minimize turbulence and promote laminar flow of fluid from the inflation passage to the outlet. Secure sealing between the nozzle and the aperture or perforation is achieved using adhesive rings, thermal bonding, or mechanical interlocks to prevent leakage and ensure precise alignment. This configuration, and the resulting laminar flow, enables the fluid to be ejected at a velocity sufficient to penetrate the target anatomy, such as a blood vessel, capillary, or similar structure.

[0066] An alternative to the individually discrete nozzle 34 of Figure 19 is the contiguous nozzle illustrated in Figure 20. This nozzle consists of two or more nozzle components joined together by a bridge. This contiguous nozzle may extend to comprise the strips 32 described earlier.

[0067] Figure 14 illustrates a drug-delivering catheter 10.5, in which the catheter tube 12.4 bifurcates near the distal end into a plurality of outwardly biased arms (OBAs)-— in this example, three-— designated 62.1, 62.2, and 62.3. Each arm includes a corresponding aperture (40.1, 40.2, 40.3). This OBA configuration provides the advantage that, upon reaching the target site, the arms can be radially expanded by inflation fluid delivered through respective inflation lumens (14.1, 14.2, 14.3). This radial deployment brings each arm into contact with the surrounding tissue, enabling the controlled delivery of therapeutic fluid — containing identical or different drugs — through the respective apertures and associated nozzles (not shown in this figure).

[0068] Figures 25 and 26 depict an alternative embodiment of the drug¬ delivering catheter 10.5. The key distinction in this design is that the OBAs do not originate and terminate at the distal end. Instead, the OBAs form an intermediate section of the catheter shaft itself, which transitions from a collapsed state (as shown in Figure 26) to a radially expanded state (as shown in Figure 25). This mid-shaft expansion enables targeted drug delivery at a location proximal to the catheter tip, while maintaining the same mechanism of inflation and fluid delivery as in the previous embodiment.

[0069] The drug-delivery catheter depicted in Figures 1 and 25 may include one or more balloon modules (not shown) positioned radially inward of theperforations. The catheter tube may comprise an inflation passage in fluid communication with the interior of the balloon module, and a separate drug pressurisation lumen in fluid communication with the apertures, allowing for delivery of a therapeutic agent. Inflation fluid introduced through the inflation passage expands the balloon module, thereby pressing the OBAs, their apertures — and their associated nozzles — into contact with the target anatomy.

[0070] Another embodiment is shown in Figures 27, 27A, and 28, illustrating a drug-delivering balloon catheter 10.6. In this embodiment, the catheter tube 12 includes a dedicated inflation lumen 14, a guidewire lumen 57, and a drug delivery and pressurisation lumen 70. The balloon component 18 can be independently inflated via the inflation lumen, separately from drug delivery, which occurs through the drug delivery lumen to the perforation 40 and its associated nozzle 34. The nozzle may optionally include a microneedle.

[0071] A key advantage of this design is the ability to independently control the inflation pressure of the balloon, allowing it to be optimised for improved nozzle or microneedle performance. This inflation pressure can be distinct from the pressure used for drug delivery, whether via microneedle or needle-free jet injection. Such separation can reduce the amount of drug required — an important consideration given the high cost of many medications— -and minimise excessive radial force on surrounding anatomy by allowing the balloon to be inflated at a lower pressure.

[0072] Because the balloon is positioned radially inward from the nozzle, its expansion during inflation pushes the nozzle outward into contact with the target anatomy, improving drug delivery efficiency. This embodiment mayinclude multiple nozzles (not shown) and can be equipped with multiple drug delivery lumens spaced circumferentially around the catheter tube.

[0073] Positioning of the catheter can be aided by radiopaque marker bands 68. The catheter tube may be formed as a coaxial structure, as illustrated in Figure 28, or as a multi-lumen extrusion, as shown in Figure 27.

Claims

CLAIMS1. A drug-delivering catheter comprising a catheter tube including a first passage, at least one aperture formed in the catheter tube that provides fluid communication between the first passage and the exterior of the catheter, and a nozzle sealingly engaged with the at least one aperture, the nozzle having a body that defines a flow channel with an inlet and an outlet, the flow channel being configured to promote laminar flow of a fluid from the first passage to the outlet.

2. A drug-delivering catheter according to claim 1 wherein the first passage comprises at least one of an inflation passage and a drug delivery passage.

3. A drug-delivering catheter according to claim 1 wherein the catheter tube comprises a plurality of outwardly biased arms, each arm having a portion of the first passage extending therethrough and including at least one aperture providing fluid communication between the first passage and the exterior of the catheter.

4. A drug-delivering catheter according to claim 4 which comprises a balloon module which is disposed radially inward of the outwardly biased arms, the catheter tube further comprising a second passage in fluid communication with the interior of the balloon module, wherein inflation of the balloon module viathe second passage causes the outwardly biased arms and their associated apertures to move into contact with the target anatomy.

5. The drug-delivering catheter according to anyone claims 1 to 4 comprising a plurality of apertures with a plurality of nozzles, each nozzle engaged with a respective aperture.

6. A drug-delivering catheter according to claim 5 wherein the plurality of nozzles is contiguous and formed as part of a strip, with the strip sealingly engaged with the catheter tube and positioned such that each aperture aligns with the flow channel of a corresponding nozzle.

7. A drug-delivering balloon catheter including a catheter tube having an inflation passage with an exit port, a balloon component including a flexible envelope, the envelope engaging the catheter tube at a proximal and a distal neck, the envelope surrounding the exit port to define an inflatable volume, the inflatable volume being inflatable by an inflow of inflation fluid through the exit port, at least one perforation formed in the flexible envelope, and a nozzle sealingly engaged with the at least one perforation, the nozzle having a body that defines a flow channel with an inlet and an outlet, the flow channel being configured to promote laminar flow of a fluid from the inflatable volume to the outlet.

8. A drug-delivering catheter according to claim 7 wherein the perforation is a pre-formed aperture which penetrates the envelope, or a latent perforation configured to open when the pressure within the inflatable volume reaches a threshold.

9. The drug-delivering balloon catheter according to claim 7 or 8 comprising a plurality of perforations with a plurality of nozzles, each nozzle engaged with a respective perforation.

10. A drug-delivering catheter according to claim 9 wherein the plurality of nozzles is contiguous and formed as part of a strip, with the strip sealingly engaged with the envelope and positioned such that each perforation aligns with the flow channel of a corresponding nozzle.

11. A drug-delivering catheter according to claim 10 wherein the strip comprises an inner side and an outer side, with the outer side configured to contact the vessel wall when the balloon component is inflated within a vessel and the inner side engages the envelope to extend longitudinally within a working region of the balloon component.

12. A drug-delivering catheter according to claim 11 wherein the outer surface of the strip comprises a plurality of raised portions, with recessed portions positioned between adjacent raised portions.

13. A drug-delivering catheter according to claim 12 wherein each nozzle comprises a needle extending from the outlet of the nozzle, forming a projection, and with each nozzle positioned within a recessed portion aligned with a corresponding flow channel.

14. A drug-delivering catheter according to claim 13 wherein the height of the needle is selected based on the target drug delivery site and the depth of tissue to be pierced.

15. A drug-delivering catheter according to anyone of claims 10 to 14 comprising a plurality of strips.

16. A drug-delivering catheter according to claim 15 wherein the strips are uniformly radially spaced around the working region of the balloon component.

17. A drug-delivering catheter according to claim 15 or 16 wherein the flexible envelope is folded in the longitudinal direction to form a plurality of pleats, each with an outer surface and an inner folded surface.

18. A drug-delivering catheter according to claim 17 wherein each strip is engaged to the outer surface of each pleat.

19. A drug-delivering catheter according to claim 18 comprising a protective sheath that covers the balloon module and extends at least the full length of the strips, the sheath being configured for retraction.

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