Flexible bag for medical solutions and associated manufacturing method

Abstract

Flexible bag for medical solutions and associated manufacturing method, wherein the bag (100) comprises a main body (1) of thermoplastic polymer (1.1), said main body (1) having a perimeter contour such that an airtight inner enclosure (2) is generated. The inner faces of the main body (1) comprise a plurality of longitudinal protrusions The flexible bag (100) also comprises removable closure means (3) arranged as a clamp on the main body (1) which divide the enclosure (2) into at least two inner chambers (4.1, 4.2) by pressing the main body (1) on a pressing area that extends from a first edge of the perimeter contour to a second edge of the perimeter contour. The main body (1) also comprises a heat-treated dividing zone comprising the pressing area. The heat treatment of the dividing zone is such that the protrusions are removed from the inner faces of the main body (1) in said dividing zone without the inner faces of the main body (1) being bonded to each other in the dividing zone.

Description

[0001] DESCRIPTION

[0002] Flexible bag for medical solutions and associated manufacturing method

[0003] TECHNICAL FIELD

[0004] The present invention relates to bags for medical solutions, in particular to flexible bags comprising auxiliary closure means for dividing the inner enclosure of the bag into different inner chambers.

[0005] PRIOR ART

[0006] Flexible bags for containing medical solutions, such as parenteral solutions, are known.

[0007] Parenteral nutrition provides the patient with the basic nutrients they need, such as sugars, salts, amino acids, vitamins, etc. These nutrients are usually contained in flexible bags in a liquid state so that they can be administered intravenously to the patient. These flexible bags are single-use and are commonly used in hospitals. Often, the hospital's own pharmacy service prepares these bags with the required nutrients, i.e. the nutrients often have to be customised for each patient.

[0008] External factors, e.g. X-rays and O2, and / or internal factors, e.g. CO2 and H2 O of the contents of the bags, determine the type of bags required. In this respect, flexible bags made of thermoplastic polymers are well known.

[0009] Sometimes it is necessary to prepare a customised recipe by mixing different nutrients to achieve the ideal composition to be administered, but the mixing of the different nutrients should be done as close as possible in time to administration to the patient so that the mixture does not lose its properties.

[0010] Flexible bags of this type can also be used for containing other medical solutions, such as medicine solutions in a liquid state.Flexible bags comprising auxiliary closure means which are placed on the bag to divide the inner enclosure forming two independent chambers are known. In this sense, document EP0313851A2 describes a flexible plastic bag comprising two independent inner chambers, said chambers being formed by separating the inner enclosure of the bag with closure means that trap a section of the bag.

[0011] GB2096569A also describes a flexible bag for parenteral nutrition, comprising a main body having a bonded perimeter contour with a bead such that an airtight inner enclosure is generated. The bag also comprises removable closure means arranged as a clamp on the main body dividing the enclosure into two inner chambers by pressing the main body on a pressing area that extends from a first edge of the perimeter contour to a second edge of the perimeter contour. The main body comprises four enlarged beadless semi-spherical welded areas adjacent to the perimeter contour bead, arranged in pairs, to ensure that the ends of the closure means can rest on them.

[0012] DISCLOSURE OF THE INVENTION

[0013] An object of the invention is to provide a flexible bag for medical solutions, as defined in claims 1 to 7.

[0014] The flexible bag for medical solutions of the invention comprises a main body of thermoplastic polymer, said main body having a perimeter contour such that an airtight inner enclosure is generated, the inner faces of the main body comprising a plurality of stretch marks separated by longitudinal protrusions. The flexible bag also comprises removable closure means arranged as a clamp on the main body which divide the enclosure into at least two inner chambers by pressing the main body on a pressing area that extends from a first edge of the perimeter contour to a second edge of the perimeter contour.

[0015] The main body comprises a heat-treated dividing zone that comprises the pressing area. The heat treatment of the dividing zone is such that the protrusions are removed from the inner faces of the main body in said dividing zone without the inner faces of the main body being bonded to each other in the dividing zone.Another object of the invention is to provide a method for manufacturing such a flexible bag, as defined in claims 8 to 15.

[0016] In the method of manufacturing the flexible bag for medical solutions of the invention, a heat treatment is carried out on an area of the main body, which will correspond to the dividing zone, by applying heat for a certain time period while pressing on the main body.

[0017] With the flexible bag and the method of the invention it is ensured that the interior of the enclosure of the flexible bag can be divided into more than one chamber, if necessary, with the closure means, ensuring that the separation between the different chambers is airtight, and therefore, the generated inner chambers are also airtight from each other.

[0018] These and other advantages and features of the invention will become apparent in view of the figures and the detailed description of the invention.

[0019] DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 shows a front view of the flexible bag according to a first embodiment of the invention.

[0021] Figure 2 shows a front view of the flexible bag of figure 1 , without the closure means.

[0022] Figure 3A shows a front view of the flexible bag of figure 1, without the closure means, and showing a detail of one embodiment of the interior of the enclosure of the bag.

[0023] Figure 3B shows a front view of the flexible bag of figure 1, without the closure means, and showing a detail of another embodiment of the interior of the enclosure of the bag.

[0024] Figure 4 shows the closure means of the flexible bag of figure 1.

[0025] Figure 5 shows schematically a previous step of the heat treatment of the dividing zone of the flexible bag of figure 1, according to an embodiment of the method of the invention.DETAILED DISCLOSURE OF THE INVENTION

[0026] The flexible bag 100 for medical solutions of the invention is a medical device, preferably sterile, of single-use intended for the preparation, preservation and / or administration of medical solutions, such as parenteral solutions for parenteral nutrition or medicine solutions, for example for chemotherapy. In the context of the invention medical solutions are understood as liquid mixtures in which the minor component (the solute) is distributed within the major component (the solvent).

[0027] Figure 1 shows a first embodiment of the flexible bag 100 of the invention, said bag 100 comprising a main body 1 of thermoplastic polymer, said main body 100 having a perimeter contour so as to generate an airtight inner enclosure 2. The flexible bag 100 also comprises removable closure means 3 arranged as a clamp on the main body 1 which divide the enclosure 2 into at least two inner chambers 4.1 and 4.2 by pressing the main body 1 on a pressing area 5’ that extends from a first edge of the perimeter contour to a second edge of the perimeter contour. The second edge is usually the opposite to the first edge.

[0028] The inner faces of the main body 1 comprise a plurality of stretch marks separated by longitudinal protrusions 10, as can be seen in the detail of the interior of the enclosure 2 shown in figure 3A, arranged parallel to the longitudinal direction Y, i.e. to the direction of evacuation of the contents of the bag 100, in order to facilitate the evacuation of the content of the bag 100, especially when the bag is almost empty. Said protrusions 10 also prevent the interior of the enclosure 2 being so sticky when the bag 100 is empty. In an embodiment of the invention, the width and depth of the stretch marks is equal or greater than 0.5 millimetres, and the width of the protrusions 10 is also equal or greater than 0.5 millimetres.

[0029] The main body 1 comprises a heat-treated dividing zone 5 that comprises the pressing area 5’. The protrusions 10 are removed from the inner faces of the main body 1 in the dividing zone 5 due to the heat treatment of said diving zone 5, but the inner faces of the main body 1 being not bonded to each other in the dividing zone 5, as will be detailed further below, i.e. in the dividing zone 5 the inner faces of the main body 1 are not welded. Namely, in the dividing zone 5 the stretch marks and the protrusions 10 disappeared and a flat and smooth zone is achieved. The closure means 3 are arranged on the dividing zone 5, being rested on an portion of said dividing zone 5, defining the pressing area 5’. The bag 100 may comprise visual marks to help the user to identify the location of the dividing zone 5, so that there is no doubt as towhere the closure means 3 should be arranged.

[0030] In the preferred embodiment of the invention, the closure means 3 are arranged perpendicular to the stretch marks and longitudinal protrusions 10 of the inner faces of the main body 1, so that thanks to the treated area of the dividing zone 5, the closure means 3 are ensured to be rested in a smooth area, an hermetic separation between the different chambers 4.1 and 4.2 being ensured when the closure means 3 are arranged over the dividing zone 5. In other words, thanks to the heat treatment carried out in the dividing zone 5, which will be detailed further below, it is possible to eliminate from the dividing zone 5 the protrusions 10, the stretch marks and also any similar irregularities that may contain the sheets 1.1 of the main body 1 and that can generate an unwanted passage of air and / or fluid between the inner chambers 4.1 and 4.2 when the closure means 3 are arranged on the dividing zone 5, thus ensuring the watertight and airtight separation of the chambers 4.1 and 4.2 due to the closure means 3 rest on a flat dividing zone 5.

[0031] The flexible bag 100 of the invention can be used as a bag 100 with a single inner enclosure 2 to contain a single parenteral solution or a single medicine solution, or as a multi-chamber bag 100, i.e. as a bag 100 whose inner enclosure 2 is divided by the closure means 3 to obtain more than one chamber, so that the same bag 100 can contain different medical solutions without mixing them, at least until they are administered to the patient. In the context of the invention, the content of each inner chamber will be referred to as a contained solution. In the case of using the bag 100 for parenteral nutrition, the contained solution will be the corresponding parenteral solution each parenteral solution comprising the necessary nutrients. In the case of using the bag 100 for containing and administering medicines, each contained solution will be the corresponding medicine solution. If the enclosure 2 is not divided by the closure means 3, in the context of the invention it is understood that the bag 100 comprises a single chamber.

[0032] Thanks to the dividing zone 5 of the flexible bag 100 of the invention, it is ensured that the separation between the different chambers is watertight, and therefore, the internal chambers 4.1 and 4.2 generated are also watertight against each other, ensuring that the medical solutions contained in each chamber are not unintentionally mixed before being administered to the patient.It is often necessary to prepare personalised prescriptions for each patient. This type of prescription requires mixing different nutrients or different medicines to achieve the ideal composition to be administered, but the mixing must be done as close as possible in time to administering to the patient so that the mixture does not lose its properties. In this sense, the different internal chambers 4.1 and 4.2 make it possible to contain different medical solutions in the same bag 100 and keep them separated from each other. Before dispensing the contents of the bag 100 to the patient, the healthcare technician disassembles the closure means 3 in such a way as to enable the contents of each chamber 4.1 and 4.2 to be mixed in the common enclosure 2, for example by shaking the bag 100, thus generating the personalised prescription. After mixing of the different medical solutions, the content of the bag 100 is ready for being administrated to the patient.

[0033] In this sense, the closure means 3 allow the inner enclosure 2 to be divided in order to generate the inner chambers 4.1 and 4.2 in a safe and fast way and, in the same way, to remove the inner chambers 4.1 and 4.2 in order to allow the mixing of the different nutrients.

[0034] The closure means 3 are fitted, and also removed, from the outside of the bag 100, i.e. the inner chambers 4.1 and 4.2 are generated by acting from the outside of the bag 100 and are also removed by acting from the outside of the bag 100, in a simple, fast and efficient manner.

[0035] The closure means 3 according to the invention comprise a first rod 3.1 comprising a longitudinal housing 3.2, as shown in figure 4, and a second rod 3.3 cooperating with the first rod 3.1, as shown in figure 1. Said second rod 3.3 is configured to be housed in the housing 3.2 in a locked position, such that when the closure means 3 are arranged over the dividing zone 5 of the main body 1 in the locked position, the dividing zone 5 is trapped between the first rod 3.1 and the second rod 3.3, forming a fold in the main body 1 which divides the enclosure 2. As the dividing zone 5 is a heat-treated zone, as will be detailed further below, the division of the enclosure 2 generated with the closure means 3 is watertight and airtight, as the generated fold is a watertight and airtight fold, as will be detailed further below.

[0036] The width of the dividing zone 5 of the main body 1 is greater than or equal to the length of the surface of the housing 3.2 according to a cross section, i.e. it is greater than or equal to the perimeter of the housing 3.2 according to said cross section. This ensures that in the locked position the generated fold is only formed by the dividing zone 5, i.e. it is only the dividing zone5 that is trapped between the first rod 3.1 and the second rod 3.3, and not another zone or section of the main body 1.

[0037] In the preferred embodiment of the invention, the first rod 3.1 comprises a U-shaped body, the housing 3.2 comprising in this case also a U-shape, as shown in figure 4, and the second rod 3.3 comprises a cylindrical body suitable for being housed in the housing 3.2. The second rod 3.3 is preferably flexible, for example of silicone, and the first rod 3.1 is preferably rigid, for example of rigid plastic or metal, which facilitates the insertion of the second rod 3.3 into the housing 3.2 of the first rod 3.1.

[0038] To further facilitate the insertion and removal of the closure means 3, the second rod 3.3 is longer than the first rod 3.1, as shown in Figure 1. In the non-limiting example shown in Figure 1 , to remove the closure means 3, it would be sufficient to pull one end of the second rod 3.3 protruding from the first rod 3.1 when the closure means 3 is in the locked position.

[0039] In another embodiment of the invention, not shown in the figures, where only the closure means 3 vary, the first rod 3.1 and the second rod 3.3 form a single piece, the second rod 3.3 being hinged at one end of the first rod 3.1. In this embodiment, the first rod 3.1 comprises a body comprising the housing 3.2 and the second rod 3.2 comprises a body comprising a protrusion which fits into the housing 3.2. In this case, in order to maintain the closure means 3 in the locked position both the first rod 3.1 and the second rod 3.2 may comprise complementary means which cooperate with each other to keep the second rod 3.3 housed in the first rod 3.1. Such complementary means are preferably arranged at the free end of the corresponding rod 3.1 and 3.3.

[0040] The dividing zone 5 according to the invention extends from one edge of the perimeter contour of the main body 1 to the opposite edge, the first rod 3.1 being at least as long as the dividing zone 5, but preferably longer, as shown in the non-limiting example in figure 1, both the first rod 3.1 and the second rod 3.3 protruding from the perimeter contour of the main body 1.

[0041] The dividing zone 5 is preferably arranged according to a transverse direction X of the main body 1 , said transverse direction X being perpendicular to a longitudinal direction Y of the bag 100 which coincides with the direction of evacuation of the contents of the flexible bag 100. Optionally, the dividing zone 5 could also be arranged parallel to the longitudinal direction Y.In the preferred embodiment of the invention the main body 1 is formed by a tubular sheet 1.1, i.e. a sheet where only the upper and lower edges are unbonded, obtained for example in an extrusion process. Optionally, the main body 1 could also be formed by two overlapping sheets 1.1. In either case, each sheet 1.1 is made of a multilayer material, comprising an inner layer of ethyl vinyl acetate (commonly known as EVA) so that the inner faces of the main body 1 forming the enclosure 2 and in contact with the medical solutions contained in the bag 100, are made of ethyl vinyl acetate (EVA). Said EVA material is a polymer suitable for regulating the biochemical reactions that take place inside the bag 100 of the invention, generating a controlled atmosphere that contributes to the preservation of the medical solutions contained in the bag 100.

[0042] In the preferred embodiment of the invention the outer layer of the multilayer material of the main body 1 is also made of ethyl vinyl acetate but to which an ultraviolet light filter has been added to prevent external factors, such as light (UV rays) and oxygen, from degrading the content of the bag 100 of the invention. In case of parenteral solutions, UV rays and oxygen for example are the main factors affecting the stability and degradation of the nutrients of the parenteral solutions.

[0043] The multilayer material of the main body 1 of the invention also comprises an intermediate layer of EVOH (ethylene vinyl alcohol), which is a thermoplastic copolymer with excellent barrier properties against gas, oxygen, hydrocarbons and organic solvents. An adhesive layer is placed between the different layers of the multilayer material of the main body 1 to hold the different layers together.

[0044] Optionally, the bag 100 of the invention can also comprise at both ends of the dividing zone 5 a reinforced bonded area 6 extending to the perimeter contour, as shown in the detail of the inside of the enclosure 2 shown in figure 3B. Said reinforced bonded areas 6 are beadless welded areas carried out preferably by a high frequency or radio frequency welding. These areas 6 reinforce the dividing zone 5 in an area close to the perimeter contour and prevent cracks from being formed near the dividing zone 5 when the closure means 3 are in the locked position and the chambers 4.1 and 4.2 are filled with the corresponding solution. Said reinforced bonded areas 6 can be considered visual marks.

[0045] In a non-limiting example, each area 6 is in the shape of a trapezoid, with the shorter side of the parallel sides of the trapezoid coinciding with the end of the dividing zone 5, so that eachtrapezoid extends from the end of the corresponding dividing zone 5 towards the perimeter edge of the bag 100, as shown in the detail of figure 3B.

[0046] As can be seen in figure 1, each chamber 4.1 and 4.2 comprises at least one conduit 7 protruding from the main body 1, so that each chamber 4.1 and 4.2 can communicate with the outside through said conduit 7. Said conduits 7 are arranged in a hermetic manner. The chambers 4.1 and 4.2 can be filled with the corresponding medical solution, for example a parenteral solution or a medicine solution, through a respective conduit 7. When the closure means 3 are disassembled and the different medical solutions have been mixed, the resulting solution or formulation can be administered to the patient through one of the conduits 7.

[0047] Optionally, each chamber 4.1 and 4.2 may comprise two conduits 7, one for refilling and one for adding additional nutrients or medicines, and even one of the chambers 4.1 or 4.2 may comprise three conduits 7, in addition to those already mentioned, another one for extracting or administering the solution.

[0048] Optionally, in an embodiment not shown in the drawings, the bag 100 of the invention may also comprise a handle 9, preferably arranged on the upper perimeter edge, to facilitate handling of the bag 100.

[0049] In the method of the invention a heat treatment is carried out on a zone of the main body 1 , which will correspond to the dividing zone 5, by applying heat for a predetermined time while pressing on said main body 1, in such a way that the protrusions 10 are removed from the internal faces of the main body 1 in said dividing zone 5 without the inner faces of the main body 1 being bonded to each other in the dividing zone 5, i.e. without being welded, so that achieving a smooth surface in the inner face of the dividing zone 5, and also in the outer face of the dividing zone 5, ensuring the watertight and airtight separation of the chambers 4.1 and 4.2 when the closure means 3 are arranged on the dividing zone 5, defining the pressing area 5’. The width of the dividing zone 5 is larger than the width of the pressing area 5’, as can be seen in figures 3A and 3B, to ensure that the closure means 3 rest in a smooth area without protrusions 10.

[0050] In a non-limiting example of the invention the pressure is exerted on the main body 1 with the inner faces in direct contact. In another non-limiting example, the pressure is exerted without the inner faces of the main body 1 being in direct contact. In another non-limiting example, andin the embodiment where the main body 1 is formed by two overlapping sheets 1.1, the pressure can be exerted on each sheet 1.1 independently, before said sheets 1.1 are joined to form the main body 1 , or jointly, in the same way as if it were a tubular sheet 1.1, the two sheets 1.1 overlapping even though they are not yet permanently joined.

[0051] In the non-limiting example where the inner faces of the main body 1 are in contact during the heat treatment of the dividing zone 5, this is carried out by applying a temperature in the range between 75°C and 100°C for a time in the range between 0.5 seconds and 2 seconds. Although in this operation the inner faces of the main body 1 do not melt and therefore do not bond to each other, it is advisable to carry out a blowing operation to facilitate the separation of these inner faces.

[0052] In the non-limiting example where the inner faces of the main body 1 are not in direct contact during the heat treatment of the dividing zone 5, in a stage prior to said heat treatment a thermally insulating sheet 8 is inserted between the inner faces of the main body 1 , as shown in the scheme of figure 5 wherein for a better understanding of the invention the non-limiting example has been represented wherein the main body 1 is formed by the two overlapping sheets 1.1, the upper overlapping sheet 1.1 not being represented in order to improve the understanding of the invention. After heat treatment, the insulating sheet 8 is removed. Said sheet 8 at least covers the dividing zone 5, but preferably the sheet 8 covers the entire main body 1, and even protrudes from the main body 1. In the scheme of figure 5 the sheet 8 is halfway through, i.e. the sheet 8 has to be pushed in further, until a flap 8.1 of the sheet 8 protrudes from the main body 1. After the heat treatment the insulating sheet 8 is removed. The sheet 8 is preferably made of polyamide, and more preferably of nylon.

[0053] In this example the heat treatment of the dividing zone 5 is carried out by applying a temperature in the range between 100°C and 140°C for a time in the range between 1 second and 5 seconds, preferably in the range between 1.4 and 2.5 seconds.

[0054] According to the method of the invention, after generating the dividing zone 5, i.e. after heat treatment of the dividing zone 5 is carried out, the unbonded edges of the main body 1 are hermetically sealed by a bonding process, forming the perimeter contour, with or without a weld bead, surrounding the inner enclosure 2. The bonding process is carried out preferably by a high frequency or radio frequency welding process in which the corresponding inner faces of the main body 1 are bonded to each other. If the main body 1 is formed by the tubular sheet1.1, the top and bottom edges, i.e. the unbonded edges, are bonded and therefore, sealed, and if the main body 1 is formed by the overlapping sheets 1.1, the top, bottom and lateral edges are bonded and therefore, sealed. In the context of the invention, bonding means that parts of the sheet or sheets 1.1 are permanently welded, i.e joined, for example by melting to generate a permanent seam when solidified. At this stage, the edges of the main body 1, preferably the upper edge and the lower edge, are prepared for the airtight placement of the conduits 7 connecting the chambers 4.1 and 4.2 with the outside, as well as the handle 9 or another necessary element.

[0055] Optionally, after heat treating the dividing zone 5, a reinforcement operation is carried out whereby a reinforced bonded area 6 is generated at each end of the dividing zone 5, said reinforced bonded area 6 being a beadless welded area. As already mentioned, each reinforced bonded area 6 extends from the corresponding end of the dividing zone 5 to an edge of the perimeter contour. These areas 6 reinforce the dividing zone 5 by preventing cracks in the bag 100 when the closure means 3 are in the locked position and the chambers 4.1 and 4.2 are filled with the corresponding medical solutions, preventing undesired leakage of the medical solutions and / or degradation of the medical solutions by contact with external agents.

[0056] Although the reinforcing operation can be carried out after the heat treatment of the dividing zone 5 as an additional operation, the heat treatment of the dividing zone 5 and the reinforcing operation could also be carried out simultaneously, so that in the same stage, and preferably on the same tooling, both operations could be carried out, thus reducing the cycle time of the method of the invention. However, in the preferred example of the invention, the reinforcement operation is carried out together with the hermetically sealing operation of the unbonded edges of the perimeter contour of the main body 1 , thus also reducing the cycle time.

[0057] After creating the perimeter contour surrounding the inner enclosure 2 in the bag 100 of the invention, the closure means 3 are positioned in such a way that the closure means 3 are arranged over the dividing zone 5, the inner enclosure 2 being divided, in a removable and airtight manner, into at least two inner chambers 4.1 and 4.2, as shown in figure 1. After creating the inner chambers 4.1 and 4.2, the inner chambers 4.1 and 4.2 are filled with the corresponding medical solutions so that they retain their properties prior to use. Prior to administering the content of the bag 100 to the patient, the closure means 3 are disassembled so that the content of both chambers 4.1 and 4.2 are mixed just prior to administration. Theclosure means 3 of the invention are as easily disassembled as they have been assembled or positioned, dismantling the inner chambers 4.1 and 4.2 immediately and efficiently.

[0058] In the example of figure 1 the bag 100 of the invention has been divided into two inner chambers 4.1 and 4.2. Optionally, in an example not shown in the drawings, the bag 100 of the invention may also be prepared so that when the closure means 3 are arranged in the locked position, the enclosure 2 is divided into three or more inner chambers. In this regard, the bag 100 may comprise a sealed bonded wall, not shown in the drawings, wherein part of the main body 1 is permanently attached at said sealed bonded wall, said wall extending from the dividing zone 5 to an edge of the perimeter contour, preferably the top or bottom edges, so that if the dividing zone 5 is arranged in the transverse direction X of the main body 1, the sealed wall is arranged in the longitudinal direction Y, i.e. in the direction of evacuation of the content of the bag 100, or vice versa, so that when the closure means 3 are fitted, the enclosure 2 is automatically divided into three chambers. If the main body 1 had more than one sealed bonded wall, the enclosure 2 could be divided into more than three chambers.

Claims

CLAIMS1. Flexible bag for medical solutions, comprising a main body (1) made of thermoplastic polymer, the main body (1) having a perimeter contour such as to create an airtight inner enclosure (2), the bag (100) comprising removable closure means (3) arranged as a clamp on the main body (1) dividing the enclosure (2) into at least two inner chambers (4.1, 4.2) by pressing the main body (1) on a pressing area (5’) that extends from a first edge of the perimeter contour to a second edge of the perimeter contour, characterised in that the inner faces of the main body (1) comprise a plurality of stretch marks separated by longitudinal protrusions (10), the main body (1) comprising a heat-treated dividing zone (5) that comprises the pressing area (5’), the heat treatment of the dividing zone (5) being such that the protrusions (10) are removed from the inner faces of the main body (1) in said dividing zone (5) without the inner faces of the main body (1) being bonded to each other in the dividing zone (5).

2. Flexible bag according to claim 1, wherein the inner faces of the main body (1) are made of ethyl vinyl acetate.

3. Flexible bag according to claim 2, wherein the main body (1) comprises two overlapping sheets (1.1) or one tubular sheet (1.1), each sheet (1.1) being formed by a multilayer material comprising an inner layer of ethyl vinyl acetate.

4. Flexible bag according to any of the preceding claims, wherein at both ends of the dividing zone (5) there is a reinforced bonded area (6) extending to the perimeter contour.

5. Flexible bag according to any of the preceding claims, wherein the closure means (3) comprise a first rod (3.1) comprising a longitudinal housing (3.2), and a second rod (3.3) cooperating with the first rod (3.1), said second rod (3.3) being configured to be housed in said housing (3.2) in a locked position, such that when the closure means (3) are arranged over the dividing zone (5) of the main body (1) in the locked position, said dividing zone (5) is trapped between the first rod (3.1) and the second rod (3.3), forming a hermetic fold in the main body (1) which divides the enclosure (2), and wherein the width of the dividing zone (5) is greater than or equal to the length of the surface of the housing (3.2) according to a cross section.

6. Flexible bag according to claim 5, wherein the first rod (3.1) and the second rod (3.3) form a single piece, the second rod (3.3) being hinged with respect to the first rod (3.1).

7. Flexible bag according to any of the preceding claims, comprising at least one conduit (7) for each inner chamber (4.1, 4.2) protruding from the main body (1), so that each inner chamber (4.1, 4.2) can communicate with the outside through said conduit (7).

8. Method of manufacturing a flexible bag for medical solutions according to any of the preceding claims, characterised in that the heat treatment of the dividing zone (5) is carried out by applying heat for a predetermined time period while pressing on the main body (1).

9. Method according to claim 8, wherein the heat treatment is carried out by applying a temperature in the range of 75°C to 100°C for a time period in the range of 0.5 seconds to 2 seconds.

10. Method according to claim 8 or 9, wherein after the heat treatment the inner faces of the main body (1) are separated in the dividing zone (5) by blowing.

11. Method according to claim 8, wherein in a stage prior to the heat treatment, a thermally insulating foil (8), preferably of polyamide and more preferably of nylon, is inserted inside the main body (1), the insulating foil (8) being removed after the heat treatment.

12. Method according to claim 11, wherein the heat treatment is carried out by applying a temperature in the range of 100°C to 140°C for a time period in the range of 1 second to 5 seconds.

13. Method according to any of claims 8 to 12, wherein, after generating the dividing zone (5), the unbonded edges of the main body (1) are hermetically sealed, forming the perimeter contour surrounding the inner enclosure (2).

14. Method according to claim 13, wherein in a reinforcement operation a reinforced bonded area (6) is generated at each end of the dividing zone (5), each area (6) extending from a corresponding end of the dividing zone (5) to the perimeter contour, wherein said reinforcement operation can be carried out simultaneously with the operation of hermetically sealing the edges of the main body (1).

15. Method according to any of claims 8 to 14, wherein after generating the inner enclosure(2), the closure means (3) are placed over the dividing zone (5), the enclosure (2) being divided, in a removable manner, into at least two inner chambers (4.1, 4.2).

Images