A drug dissolution tester and calibration method thereof

Abstract

The present invention belongs to the field of drug testing instruments, and relates to a drug dissolution tester and a calibration method thereof. The drug dissolution tester comprises a frame, a water bath, a dissolution cup, a stirring paddle and a driving mechanism. The dissolution cup is detachably mounted in a cup hole of the water bath. A calibration cover is placed on the cup mouth of the dissolution cup in a coaxial positioning manner. The surface layer of the calibration cover is a pressure-sensitive imaging layer. A calibration hole adapted to the paddle shaft of the stirring paddle is coaxially arranged in the center of the calibration cover. When the inverted paddle shaft is coaxial with the dissolution cup, the paddle shaft passes through the calibration hole and then extends into the dissolution cup. When the inverted paddle shaft is not coaxial with the dissolution cup, the paddle shaft cannot pass through the calibration hole, and the pressure-sensitive imaging layer of the calibration cover senses the paddle shaft and develops on the calibration cover to indicate the eccentric position of the paddle shaft. A fine-tuning mechanism is installed on the top plate of the water bath, which is used to fine-tune the position of the dissolution cup in the cup hole according to the development. The present invention can quickly calibrate the coaxiality of the paddle shaft and the dissolution cup.

Description

Technical Field

[0001] The invention belongs to the technical field of drug detection, and particularly relates to a drug dissolution tester and a calibration method thereof. Background Art

[0002] The drug dissolution tester is suitable for the dissolution test of oral solid preparations. It can simulate the gastrointestinal environment and digestion process of the human body. It is an in vitro test device for detecting the intrinsic quality of drug preparations and is widely used in drug research, production and inspection. According to the different ways of stirring the drug, the drug dissolution tester is roughly divided into two types: rotating basket and rotating paddle.

[0003] Among them, for the dissolution tester with stirring paddle, according to the relevant requirements of the national pharmaceutical machinery industry standard for the test method of drug dissolution tester (JB / T 20076-2013): when the stirring paddle rotates, the deviation between the paddle shaft and the vertical axis of the dissolution cup at any point should not be greater than 2.0 mm, that is, the coaxiality deviation between the paddle shaft and the dissolution cup needs to be controlled. The industry standard also publishes the coaxiality measurement method: using a dial indicator to measure the deviation between the paddle shaft and the vertical axis of the dissolution cup when the stirring paddle rotates, the deviation value is accurately measured. However, it does not publish a method for quickly calibrating the coaxiality deviation between the paddle shaft and the dissolution cup.

[0004] To solve the above problems, the existing dissolution tester is disclosed in the drawings of patent CN215678341U, or Figure 1 As shown in FIG. 1 , multiple cams are installed around the dissolution cup, and the cams are rotated to squeeze the dissolution cup, thereby changing the position of the dissolution cup to calibrate the coaxiality between the dissolution cup and the paddle axis. However, this method cannot achieve rapid calibration because the rotation angle of each cam needs to be coordinated multiple times to make the dissolution cup exactly in the calibration position. Summary of the invention

[0005] In view of the existing difficulties, the present invention provides a drug dissolution tester to solve the problem that the coaxiality deviation between the paddle shaft and the dissolution cup cannot be quickly calibrated.

[0006] A drug dissolution tester, comprising a frame, a water bath, a dissolution cup, a stirring paddle and a driving mechanism, wherein the dissolution cup is detachably mounted in a cup hole of the water bath, the stirring paddle is driven by the driving mechanism on the frame to rotate in the dissolution cup, a calibration cover is coaxially positioned on the cup mouth of the dissolution cup, a calibration hole adapted to the paddle shaft of the stirring paddle is coaxially arranged at the center of the calibration cover, and when the paddle shaft is coaxial with the dissolution cup, the paddle shaft passes through the calibration hole and then extends into the dissolution cup;

[0007] The surface layer of the calibration cover is a pressure-sensitive imaging layer. When the paddle shaft is not coaxial with the dissolution cup, it cannot pass through the calibration hole. After the pressure-sensitive imaging layer senses the paddle shaft, it is developed on the calibration cover to indicate the eccentric position of the paddle shaft.

[0008] A fine-adjustment mechanism is installed on the top plate of the water bath box, which is used to fine-adjust the position of the dissolution cup in the cup hole according to the development.

[0009] Preferably, the fine-tuning mechanism comprises at least two groups of cam assemblies, and the cam assemblies are distributed at intervals on a virtual circle coaxial with the cup hole;

[0010] The area of ​​the development is divided into two equal parts by the center line, the cam assembly is moved to the calibration position, at least two groups of cam assemblies are located on the opposite side of the development and are arranged on opposite sides of the center line, and the cam of the cam assembly is rotated to push the dissolution cup toward the development side, so that the calibration hole is coaxial with the paddle shaft.

[0011] As an optional solution for the fine-tuning mechanism, a circle of mounting holes is arrayed along the outer circumference of the cup hole on the top plate of the water bath, and the cam assembly is installed in the mounting holes corresponding to the calibration position, thereby changing the position on the virtual circumference of the cam assembly. The cam assembly in this solution includes a rotating shaft and a cam keyed to the rotating shaft, and the rotating shaft and the mounting hole are connected by a damping connection to increase the friction between them and prevent the rotating shaft from rotating freely relative to the mounting hole.

[0012] As another optional solution of the fine-tuning mechanism, the water bath is provided with a gear ring 1 and a gear ring 2 coaxial with the cup hole, and the gear ring 2 is located outside the gear ring 1;

[0013] The cam assembly comprises a gear, a rotating shaft and a cam, wherein the gear is meshed between the first gear ring and the second gear ring at the same time, and the gear and the cam are staggeredly mounted on the rotating shaft up and down;

[0014] The rotating shaft moves up and down to change the height of the cam. In the process of the gear being transferred to the calibration position by the rotating gear ring 1 or gear ring 2, the cam is not in the same plane as the edge of the dissolution cup and does not contact the edge of the cup.

[0015] Furthermore, there is no restraining force between the rotating shaft and the gear in the R-axis direction.

[0016] Preferably, the cup edge of the dissolution cup protrudes out of the cup hole, and the cam abuts against the outer side wall of the cup edge during calibration;

[0017] A positioning ring groove for positioning the calibration cover is arranged inside the cup mouth of the dissolution cup.

[0018] Furthermore, the top surface of the gear is fixedly mounted with an end face gear block 1 for locking the cam, and the bottom surface of the cam is fixedly mounted with an end face gear block 2;

[0019] After the calibration is completed, the rotating shaft continues to be moved downward so that the second end face tooth block engages with the first end face tooth block, and the cam continues to abut against the edge of the cup.

[0020] Preferably, an annular mounting groove for mounting a rotating shaft is provided on the top plate of the water bath, and a damping connection is formed between the rotating shaft and the mounting groove for maintaining the rotating shaft at different heights, and / or: a ball spring pin is installed in the mounting groove of the top plate in a horizontal direction, a concave ring matching the ball of the ball spring pin is provided on the rotating shaft, and the ball is embedded in the concave ring to limit the height of the rotating shaft.

[0021] The installation grooves are respectively installed with a first ball spring pin for keeping the rotating shaft at a first height and a second ball spring pin for keeping the rotating shaft at a second height. The first ball spring pin is located above the second ball spring pin.

[0022] Another object of the present invention is a calibration method of a drug dissolution tester, corresponding to the first optional scheme of the fine-tuning mechanism, comprising the following steps:

[0023] The dissolution cup is placed in the cup hole of the water bath, and there is a clearance fit between the dissolution cup and the cup hole;

[0024] Placing a calibration cover on the mouth of the dissolution vessel, wherein the calibration cover is coaxial with the dissolution vessel;

[0025] Insert the stirring paddle upside down into the socket on the top cover of the frame, push the stirring paddle downward, and observe whether the paddle shaft can smoothly pass through the calibration hole of the calibration cover;

[0026] If the paddle shaft can pass through the calibration hole, the stirring paddle is coaxial with the dissolution vessel; if the paddle shaft cannot pass through the calibration hole, a display appears on the calibration cover to indicate the deviation position of the dissolution vessel; the display is divided into two parts by the center line;

[0027] Moving the cam assembly into the mounting hole of the calibration position so that at least two groups of cam assemblies are located on opposite sides of the developing image and arranged on opposite sides of the center line;

[0028] The cam of the cam assembly is rotated to push the dissolution cup toward the developing side so that the calibrated hole is coaxial with the paddle shaft.

[0029] Another object of the present invention is to provide a calibration method for a drug dissolution tester, corresponding to the second optional scheme of the fine-tuning mechanism, comprising the following steps:

[0030] The dissolution cup is placed in the cup hole of the water bath, and there is a clearance fit between the dissolution cup and the cup hole;

[0031] Placing a calibration cover on the mouth of the dissolution vessel, wherein the calibration cover is coaxial with the dissolution vessel;

[0032] Insert the stirring paddle upside down into the socket on the top cover of the frame, push the stirring paddle downward, and observe whether the paddle shaft can smoothly pass through the calibration hole of the calibration cover;

[0033] If the paddle shaft can pass through the calibration hole, the stirring paddle is coaxial with the dissolution vessel; if the paddle shaft cannot pass through the calibration hole, a display appears on the calibration cover to indicate the deviation position of the dissolution vessel; the display is divided into two parts by the center line;

[0034] In an initial state, the cam is located at a first height higher than the edge of the dissolution cup; the gear ring 1 or the gear ring 2 is rotated to move at least two groups of cam assemblies to the opposite side of the development and arranged on opposite sides of the center line;

[0035] Pushing the cam downward to a second height so that the cam can contact the cup edge when rotating;

[0036] The cam is rotated to push the dissolution cup toward the developing side so that the calibrated hole is coaxial with the paddle shaft.

[0037] The beneficial effects of the present invention are:

[0038] The present invention places a calibration cover with a calibration hole on the cup mouth of the dissolution cup, converts the coaxiality detection of the dissolution cup and the paddle shaft into the coaxiality detection of the calibration hole and the paddle shaft, and arranges a pressure-sensitive imaging layer on the surface of the calibration cover to clearly and intuitively display the eccentric position of the dissolution cup and the paddle shaft, provides a direction guide for the adjustment action of the fine-tuning mechanism, and facilitates improving the calibration efficiency of the dissolution cup.

[0039] The fine adjustment mechanism of the present invention divides the development into two parts by using the center line, and adjusts the position of the cam assembly to the opposite sides of the center line, so that the dissolution cup can be calibrated with only two cam assemblies, and the calibration speed is fast and the accuracy is high.

[0040] A cam assembly of the present invention utilizes the coordinated cooperation between two gear rings, gears, a rotating shaft, a cam and a dissolution cup to quickly transfer the cam to a calibration position; and by changing the height of the cam, the cam and the dissolution cup do not interfere with each other during the rotation of the gear, and the cam is quickly switched between an initial state, a calibration state and a locking state, the operation is easy, and the calibration result is stable and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0042] Figure 1 It is a top view schematic diagram of the layout structure of the prior art using a cam to calibrate the dissolution cup;

[0043] Figure 2 is a side structural schematic diagram of an embodiment of the present application;

[0044] Figure 3 This is a schematic diagram of the top view of the structure of the first fine-tuning mechanism of the present application before calibration of the dissolution cup;

[0045] Figure 4 This is a schematic diagram of the top view of the structure after the dissolution cup is calibrated by the first fine-tuning mechanism of the present application;

[0046] Figure 5 It is a schematic diagram of the top view of the structure of the second fine-tuning mechanism of the present application during the calibration process of the dissolution cup, in which the two groups of cam assemblies in the figure move to the calibration position;

[0047] Figure 6 is with Figure 5 A schematic cross-sectional view of the corresponding fine-tuning mechanism and the dissolution cup;

[0048] Figure 7 It is a schematic diagram of the top view of the structure of the second fine-tuning mechanism of the present application during the calibration process of the dissolution cup, in which a rotating cam is prepared;

[0049] Figure 8 This is a schematic diagram of the top view of the structure after the second fine-tuning mechanism of the present application is calibrated on the dissolution cup, in which the cam is rotated and abuts against the edge of the cup;

[0050] Fig. 9 is with Figure 8 A schematic cross-sectional view of the corresponding fine-tuning mechanism and the dissolution cup;

[0051] Fig.10 It is a schematic diagram showing the structure in which the cam is locked on the top of the water bath;

[0052] Fig.11 It is a partial schematic diagram of the matching structure when the ball spring pin 2 limits the rotating shaft to the second height;

[0053] Fig.12 It is a schematic diagram of the structure of the end face gear block 2 when viewed from above.

[0054] Reference numerals:

[0055] 1. Frame; 11. Shell; 12. Socket;

[0056] 2. Water bath; 21. Top plate; 211. Cup hole; 212. Mounting hole; 213. Mounting slot; 214. Ball spring pin 1; 215. Ball spring pin 2; 2151. Ball;

[0057] 3. Dissolution cup; 31. Cup edge; 32. Positioning ring groove;

[0058] 4. stirring paddle; 41. paddle shaft;

[0059] 5. calibration cover; 51. calibration hole; 52. development;

[0060] 6. Cam assembly; 61. Rotating shaft; 611. Concave ring; 62. Cam; 63. Gear; 64. End face gear block 1; 65. End face gear block 2; 66. Conical teeth;

[0061] 7. Ring gear 1;

[0062] 8. Ring gear 2;

[0063] 9. Center line. DETAILED DESCRIPTION

[0064] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0065] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs.

[0066] like Figures 1 to 12 As shown, in order to solve the problem of insufficient calibration accuracy and poor controllability of the coaxiality between the dissolution cup and the paddle shaft during the calibration process, the present application provides a drug dissolution tester, including a frame 1, a water bath 2, a dissolution cup 3, a stirring paddle 4 and a driving mechanism. Please refer to Figure 2 , the water bath 2 is mounted on the frame 1, and is used to heat the dissolution cup 3 at a constant temperature. A movable shell 11 is provided on the frame 1 above the water bath 2, and a socket 12 for positioning the stirring paddle 4 is provided in the shell 11. A driving mechanism (not shown) connected to the stirring paddle 4 is also installed in the shell 11, and is used to drive the stirring paddle 4 to rotate. As an optional method, the shell 11 can be set as a hinged flip-cover structure, and the dissolution cup 3 can be taken / put in the water bath after the shell 11 is flipped up; in addition, the shell 11 can also be set as a lifting structure, and the dissolution cup 3 can be taken / put in the water bath after the shell 11 is raised.

[0067] The dissolution cup 3 is detachably installed in the cup hole 211 of the water bath 2. There is a clearance fit between the dissolution cup 3 and the cup hole 211. Although the clearance is small, it may still cause a deviation in the coaxiality between the dissolution cup 3 and the paddle shaft.

[0068] Please refer to Figure 2A calibration cover 5 is coaxially positioned on the mouth of the dissolution cup 3, and a calibration hole 51 adapted to the paddle shaft 41 of the stirring paddle 4 is coaxially arranged at the center of the calibration cover 5. When the paddle shaft 41 is coaxial with the dissolution cup 3, the paddle shaft 41 just passes through the calibration hole 51 and extends into the dissolution cup 3; when the paddle shaft 41 is not coaxial with the dissolution cup 3, the paddle shaft cannot pass through the calibration hole 51.

[0069] Specifically, please refer to Figure 2 and Figure 6 A positioning annular groove 32 coaxial with the dissolution cup 3 is provided on the inner side of the cup mouth of the dissolution cup 3. Before calibration, the calibration cover 5 is placed in the positioning annular groove 32, which ensures the coaxiality of the two and prevents the calibration cover from displacement. Preferably, the calibration cover 5 and the positioning annular groove 32 are tightly fitted to ensure the coaxiality between them.

[0070] The surface of the calibration cover 5 is covered with a pressure-sensitive imaging layer made of a pressure-sensitive imaging material, such as Figure 3 and Figure 5 As shown, when the paddle shaft 41 cannot pass through the calibration hole 51, the paddle shaft applies pressure to the calibration cover 5 near the edge of the calibration hole 51. After the pressure-sensitive imaging layer senses the pressure of the paddle shaft, a development 52 is formed at the pressure position on the calibration cover 5 to indicate the eccentric position of the paddle shaft. An industrial camera can be installed on the frame 1 to capture the development image and transmit it to the display screen for magnified display, so that the image and position of the development 52 can be clearly observed; the position of the development 52 can also be observed manually.

[0071] A fine adjustment mechanism is installed on the top plate 21 of the water bath 2 for finely adjusting the position of the dissolution cup 3 in the cup hole 211 according to the development 52, so as to calibrate the coaxiality between the dissolution cup and the paddle shaft.

[0072] In order to facilitate the fine-tuning mechanism to calibrate the dissolution cup 3, a center line 9 can be drawn by the computer software to divide the developed image 52 into two parts. At this time, it is well known that the computer and the display screen are connected in communication. Figure 3 and Figure 5 As shown, the center line 9 connects the widest part of the developed image and the center of the calibration hole 51 , and extends to the side away from the developed image 52 .

[0073] The fine-tuning mechanism includes multiple groups of cam assemblies 6, and the present application takes two groups as an example for explanation. The cam assemblies 6 are spaced apart on a virtual circle coaxial with the cup hole 211. First, the cam assemblies 6 are moved to the calibration position, that is, the two groups of cam assemblies 6 are located on the opposite sides of the developing device 52 and are arranged on the opposite sides of the center line 9, and then the cam 62 of the cam assembly 6 is rotated to push the dissolution cup 3 toward one side of the developing device 52, so that the calibration hole 51 is coaxial with the paddle shaft. Fig. 9As shown, the cup edge 31 of the dissolution cup 3 of the present application protrudes outward from the cup hole 211 , and during calibration, the cam 62 is rotated to abut against the outer side wall of the cup edge 31 and slightly push the cup edge 31 .

[0074] Because the position of the developing image 52 indicates the target moving direction of the dissolution cup 3, the position of the cam assembly 6 is first determined so that the cam assembly 6 can squeeze the dissolution cup 3 from different directions diagonally opposite to the developing image 52, thereby limiting the moving direction of the dissolution cup 3 and preventing the dissolution cup 3 from deviating from the set calibration direction.

[0075] The present application does not impose precise restrictions on the calibration position of the cam assembly 6. The two groups of cam assemblies 6 can be completely symmetrical or asymmetrical with the center line as the center, but they both need to be distributed on different sides of the center line. Preferably, the angle a between the line from the axis of the cam assembly 6 to the starting point of the center line and the center line is 20-45°, and they are symmetrically arranged. If the angle is too small, the limiting effect of the two groups of cam assemblies 6 on the dissolution cup 3 is weakened; if the angle is too large, it increases the difficulty of adjusting the rotation angle of the cam 62, and it is difficult to coordinate two cams 62 that are far apart at the same time and accurately determine their rotation angles.

[0076] As an optional solution for the fine-tuning mechanism, the fine-tuning mechanism is calibrated manually. For details, please refer to Figure 3 A circle of mounting holes 212 is arranged on the top plate 21 of the water bath 2 along the outer periphery of the cup hole 211. Before calibration, the cam assembly 6 is first installed in the corresponding mounting holes 212, so that the cam assembly 6 enters the calibration position.

[0077] The cam assembly 6 in this solution includes a rotating shaft 61 and a cam 62 connected to the rotating shaft 61 by a key. The rotating shaft 61 and the mounting hole 212 are connected by a damping connection to increase the friction between them. When the cam 62 abuts against the cup edge 31 of the dissolution cup 3, the cup edge 31 also applies a reverse pressure to the cam 62, and the damping force can resist the reverse pressure and other external vibration interference, preventing the cam 62 and the rotating shaft 61 from freely rotating relative to the mounting hole 212 to loosen the dissolution cup 3, thereby improving the stability of the calibration result.

[0078] The calibration method of the above-mentioned drug dissolution tester comprises the following steps:

[0079] Place the dissolution cup 3 in the cup hole 211 of the water bath 2, with a clearance fit between the dissolution cup 3 and the cup hole 211;

[0080] Place the calibration cover 5 on the positioning ring groove 32 of the mouth of the dissolution cup 3, so that the calibration cover 5 and the dissolution cup 3 are coaxial;

[0081] Insert the stirring paddle 4 upside down into the insertion hole 12 on the top cover of the frame 1, with the end of the stirring paddle 4 without blades facing downward, push the stirring paddle 4 downward, and observe whether the paddle shaft can smoothly pass through the calibration hole 51 of the calibration cover 5;

[0082] If the paddle shaft can pass through the calibration hole 51, the stirring paddle 4 is coaxial with the dissolution cup 3; if the paddle shaft cannot pass through the calibration hole 51, a development 52 appears on the calibration cover 5, indicating the deviation position between the dissolution cup 3 and the paddle shaft, and the dissolution cup 3 needs to be calibrated with reference to the position of the development 52;

[0083] Start calibration of vessel 3:

[0084] Please refer to Figure 3 and Figure 4 , in order to facilitate calibration, the development 52 is first divided into two parts by the center line;

[0085] Move the cam assembly 6 into the mounting hole 212 at the calibration position, so that at least two groups of cam assemblies 6 are located on opposite sides of the developing surface 52 and arranged on opposite sides of the center line;

[0086] The cam 62 of the cam assembly 6 is rotated to push the dissolution cup 3 in the direction of the developing portion 52 so that the calibration hole 51 is coaxial with the paddle shaft.

[0087] As another optional solution for the fine-tuning mechanism, the water bath 2 is provided with a gear ring 1 7 and a gear ring 2 8 coaxial with the cup hole 211, and the gear ring 2 8 is located on the outside of the gear ring 1 7. One of the gear ring 1 7 and the gear ring 2 8 is fixedly installed, and the other is rotatably installed. Preferably, the gear ring 1 7 is fixedly installed to prevent it from rotating and touching the dissolution cup 3. The gear ring 1 7 is an outer gear ring, and the gear ring 2 8 is an inner gear ring. The dead weight of the gear ring 2 and the friction between it and the top plate keep it reliably on the top plate, unless it is subjected to a sufficiently large external twisting force; or a magnet sheet of different polarity is installed between the gear ring 2 8 and the top plate, and the magnet sheet of the gear ring 2 8 adsorbs the magnet sheet of the top plate under normal conditions, thereby locking the gear ring 2 in the rotation direction.

[0088] Please refer to Figure 6 , Fig. 9 and Fig.10 The cam assembly 6 includes a gear 63, a rotating shaft 61 and a cam 62, and the gear 63 is meshed between the ring gear 1 7 and the ring gear 2 8. The gears 63 and the cams 62 are installed alternately on the rotating shaft 61, and the present application takes the cam 62 located above the gear 63 as an example for explanation. When it is necessary to move the cam 62 to the calibration position, the ring gear 2 8 is rotated, and the ring gear 2 8 drives the gear 63 to move around the ring gear 1 7 until the gear 63 is moved into the calibration position.

[0089] The top plate 21 of the water bath 2 is provided with an annular mounting groove 213 for mounting the rotating shaft 61, and the rotating shaft 61 can move up and down relative to the mounting groove 213. The cam 62 and the rotating shaft 61 are connected by a transmission type, for example, the cam 62 can be fixedly mounted on the rotating shaft 61, or a key connection is adopted. The present application does not limit the specific fixed connection method. When the rotating shaft 61 moves up and down, the height of the cam 62 is changed. When the gear 63 is transferred to the calibration position by the rotating gear ring 28, the cam 62 is located at a first height, such as Figure 6 As shown, at this time, the cam 62 and the cup edge 31 of the dissolution cup 3 are not in the same height plane, so the cam 62 will not contact the cup edge 31 when rotating, and will not accidentally hit the dissolution cup 3.

[0090] During calibration, the cam 62 is pushed down to a second height, such as Fig. 9 As shown, at this time, at least a portion of the height of the cam 62 overlaps with the cup edge 31 , so the cam 62 can contact the cup edge 31 when rotating, and then push the cup edge 31 .

[0091] There is no restraint force between the rotating shaft 61 and the gear 63 in the R-axis direction of the present application, that is, the contact section between the rotating shaft 61 and the gear 63 is an optical axis, so the gear 63 can rotate freely relative to the rotating shaft 61. However, there is a restraint force between the rotating shaft 61 and the cam 62 in the R-axis direction, so when the cam 62 is rotated, the rotating shaft 61 rotates synchronously with the cam 62, while the gear 63 no longer rotates and is held in the calibration position by two gear rings, thereby improving the reliability of the calibration process.

[0092] After the calibration is completed, in order to make the cam 62 stably against the cup edge 31 and prevent the cam 62 from rotating due to the reverse pressure of the cup edge 31 and external vibration, the present application fixes the end face tooth block 1 64 for locking the cam 62 on the top surface of the gear 63, and fixes the end face tooth block 2 65 adapted to the end face tooth block 1 64 on the bottom surface of the cam 62. The end surfaces where the end face tooth block 1 64 and the end face tooth block 2 65 contact are densely covered with a plurality of strip-shaped tooth edges, and the strip-shaped tooth edges are radially distributed with the center of the end face tooth block 1 64 or the end face tooth block 2 65. Or as Fig.12 As shown, the end faces of the end face tooth block 1 64 and the end face tooth block 2 65 that are in contact are densely covered with conical teeth 66 , and the conical teeth 66 can enable the end face tooth block 1 64 and the end face tooth block 2 65 to mesh together reliably.

[0093] Please refer to Fig.10 After the calibration is completed, continue to push the cam 62 downward to the third height so that the end face tooth block 65 engages with the end face tooth block 64. At this time, the cam 62 is locked in the R-axis rotation direction, so the cam 62 can continue to reliably abut the cup edge 31, and will not be squeezed by the cup edge 31 and forced to rotate, nor will it rotate due to external vibration.

[0094] In other specific implementations, rough friction plates may be installed on the bottom surface of the cam 62 and the top surface of the gear 63, and the two friction plates engage with each other, thereby locking the cam 62 in the rotation direction.

[0095] There is a damping connection between the rotating shaft 61 and the mounting groove 213, and the damping force is used to keep the rotating shaft 61 at different heights, thereby keeping the cam 62 at different heights. Specifically, the inner wall of the mounting groove 213 is a rough surface, and the part of the rotating shaft 61 that contacts the mounting groove 213 is also a rough surface; or the part of the rotating shaft 61 that contacts the mounting groove 213 is covered with a layer of high damping material, and the material of the high damping material is rubber. Of course, other damping materials known in the art can also be used, and this application does not limit this. It can be understood that the external force applied to the gear ring 2 during calibration is greater than the damping force, so the damping force is not enough to prevent the rotating shaft 61 from moving along the gear ring 1 within the virtual circumference.

[0096] In a specific embodiment, as an alternative or supplementary solution to the above solution, a ball spring pin is installed in the installation groove 213 of the top plate 21 along the horizontal direction, and a concave ring 611 adapted to the ball 2151 of the ball spring pin is provided on the rotating shaft 61, such as Figure 6 , Figure 9-11 As shown, the ball 2151 is embedded in the concave ring 611 to limit the height of the rotating shaft 61. Figure 6 and Fig. 9 As shown, a ball spring pin 1 214 for keeping the rotating shaft 61 at a first height and a ball spring pin 215 for keeping the rotating shaft 61 at a second height are respectively installed in the installation groove 213, and the ball spring pin 1 214 is located above the ball spring pin 215. When the cam 62 is located at the first height, the ball spring pin 1 214 is embedded in the concave ring 611 of the rotating shaft 61, and when the cam 62 is pushed to the second height, the ball spring pin 215 is embedded in the concave ring 611 of the rotating shaft 61. Preferably, the longitudinal section of the concave ring 611 on the rotating shaft is an arc, and the top and bottom transitions of the concave ring 611 are both provided with rounded corners, so that the ball can be smoothly embedded in or out of the concave ring 611. The bottom of the rotating shaft 61 is also provided with rounded corners accordingly.

[0097] The calibration method of the above-mentioned drug dissolution tester comprises the following steps:

[0098] Place the dissolution cup 3 in the cup hole 211 of the water bath 2, with a clearance fit between the dissolution cup 3 and the cup hole 211;

[0099] Place the calibration cover 5 on the mouth of the dissolution cup 3, and the calibration cover 5 is coaxial with the dissolution cup 3;

[0100] Insert the stirring paddle 4 upside down into the insertion hole 12 on the top cover of the frame 1, push the stirring paddle 4 downward, and observe whether the paddle shaft can smoothly pass through the calibration hole 51 of the calibration cover 5;

[0101] If the paddle shaft can pass through the calibration hole 51, the stirring paddle 4 is coaxial with the dissolution cup 3; if the paddle shaft cannot pass through the calibration hole 51, the image 52 appearing on the calibration cover 5 indicates the deviation position between the dissolution cup 3 and the paddle shaft, and the dissolution cup 3 is ready to be calibrated;

[0102] Start calibration of vessel 3:

[0103] Please refer to Figure 5 , the center line divides the development 52 into two parts;

[0104] Please refer to 6. In the initial state, the cam 62 is located at the first height. The ball spring pin 1 and the concave ring cooperate to limit the rotating shaft to the first height. At this time, the cam 62 is higher than the cup edge 31 of the dissolution cup 3. The gear ring 2 8 is rotated to move at least two groups of cam assemblies 6 to the opposite side of the developing device 52 and are arranged on opposite sides of the center line, for example Figure 5 As shown, one cam assembly 6 is located on the upper left side of the developing device 52, and the other cam assembly 6 is located on the lower left side of the developing device 52;

[0105] Please refer to Figures 7 to 9 , push the cam 62 downward to the second height, the ball spring pin 2 and the concave ring cooperate to keep the rotating shaft at the second height, rotate the cam 62, and make the cam 62 push the dissolution cup 3 in the direction of the developer 52, that is, to the right, until the calibration hole 51 is coaxial with the paddle shaft. Since the two cams 62 push the dissolution cup 3 from the upper left and lower left sides of the developer 52 respectively, and there is no workable cam 62 on the right side of the developer 52, it is more convenient to adjust the two cams 62 on the left side, and there is no need to consider the coordination between the cam 62 on the right and the two cams 62 on the left side, which is more convenient to operate;

[0106] Please refer to Fig.10 , continue to push the cam downward to make the ball spring pin 2 disengage from the concave ring until the end face tooth block 1 64 abuts against the end face tooth block 2 65 and they bite each other, locking the cam at the current angle and continuously abutting against the edge of the cup;

[0107] After the calibration is completed, the calibration cover 5 is removed and preparation for the dissolution test of the drug begins.

[0108] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention is described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A drug dissolution tester, comprising a frame, a water bath, a dissolution cup, a stirring paddle and a driving mechanism, wherein the dissolution cup is detachably mounted in a cup hole of the water bath, and the stirring paddle is driven by the driving mechanism on the frame to rotate and stir the drug in the dissolution cup, characterized in that: A calibration cover is coaxially placed on the mouth of the dissolution cup, the surface layer of the calibration cover is a pressure-sensitive imaging layer, and a calibration hole adapted to the paddle shaft of the stirring paddle is coaxially arranged at the center of the calibration cover; When the inverted paddle shaft is coaxial with the dissolution cup, the paddle shaft passes through the calibration hole and then extends into the dissolution cup; When the inverted paddle shaft is not coaxial with the dissolution vessel, the paddle shaft cannot pass through the calibration hole, and the pressure-sensitive imaging layer of the calibration cover senses the paddle shaft and develops on the calibration cover to indicate the eccentric position of the paddle shaft; A fine-adjustment mechanism is installed on the top plate of the water bath box, for fine-adjusting the position of the dissolution cup in the cup hole according to the development; The fine-tuning mechanism comprises at least two groups of cam assemblies, and the cam assemblies are distributed at intervals on a virtual circle coaxial with the cup hole; The developing surface is divided into two parts by a center line, and the cam assembly is moved to a calibration position so that at least two groups of cam assemblies are located on opposite sides of the developing surface and arranged on opposite sides of the center line, and the cams of the cam assembly are rotated to push the dissolution cup toward the developing surface, so that the calibration hole is coaxial with the paddle shaft.

2. The drug dissolution tester according to claim 1, characterized in that: A circle of mounting holes is arrayed along the outer circumference of the cup hole on the top plate of the water bath, and the cam assembly is installed in the mounting holes corresponding to the calibration position, thereby changing the position of the cam assembly on the virtual circle.

3. The drug dissolution tester according to claim 1, characterized in that: The water bath is provided with a gear ring 1 and a gear ring 2 which are coaxial with the cup hole, and the gear ring 2 is located outside the gear ring 1; The cam assembly comprises a gear, a rotating shaft and a cam, the gear is meshed between the first gear ring and the second gear ring, and the gear and the cam are installed on the rotating shaft at intervals; The cam can move up and down following the rotating shaft. In the process that the gear is transferred to the calibration position by the rotating gear ring 1 or gear ring 2, the cam is not in the same plane as the edge of the dissolution cup and thus does not contact the edge of the cup.

4. The drug dissolution tester according to claim 3, characterized in that: There is no restraining force between the rotating shaft and the gear in the R-axis direction; The cup edge of the dissolution cup protrudes out of the cup hole, and the cam abuts against the outer side wall of the cup edge during calibration; A positioning ring groove for positioning the calibration cover is arranged inside the cup mouth of the dissolution cup.

5. The drug dissolution tester according to claim 3, characterized in that: The top surface of the gear is fixedly mounted with an end face tooth block 1 for locking the cam, and the bottom surface of the cam is fixedly mounted with an end face tooth block 2; After the calibration is completed, the rotating shaft continues to be moved downward until the second end face tooth block engages with the first end face tooth block, so that the cam continuously abuts against the edge of the cup.

6. The drug dissolution tester according to claim 3, characterized in that: An annular mounting groove for mounting the rotating shaft is provided on the top plate of the water bath, and a damping connection is formed between the rotating shaft and the mounting groove to keep the rotating shaft at different heights; And / or: a ball spring pin is installed in the installation groove of the top plate in the horizontal direction, a concave ring adapted to the ball of the ball spring pin is provided on the rotating shaft, and the ball is embedded in the concave ring to limit the height direction of the rotating shaft.

7. The drug dissolution tester according to claim 6, characterized in that: A ball spring pin 1 for keeping the rotating shaft at a first height and a ball spring pin 2 for keeping the rotating shaft at a second height are respectively installed in the installation groove, and the ball spring pin 1 is located above the ball spring pin 2.

8. A calibration method for a drug dissolution tester according to claim 2, characterized in that: The following steps are involved: The dissolution cup is placed in the cup hole of the water bath, and there is a clearance fit between the dissolution cup and the cup hole; Placing a calibration cover on the mouth of the dissolution vessel, wherein the calibration cover is coaxial with the dissolution vessel; Insert the stirring paddle upside down into the socket on the top cover of the frame, push the stirring paddle downward, and observe whether the paddle shaft can smoothly pass through the calibration hole of the calibration cover; If the paddle shaft can pass through the calibrated hole, the paddle is coaxial with the dissolution vessel; If the paddle shaft cannot pass through the calibration hole, a display appears on the calibration cover to indicate the offset position of the dissolution vessel; the display is divided into two parts by the center line; Moving the cam assembly into the mounting hole of the calibration position so that at least two groups of cam assemblies are located on opposite sides of the developing image and arranged on opposite sides of the center line; The cam of the cam assembly is rotated to push the dissolution cup toward the developing side so that the calibrated hole is coaxial with the paddle shaft.

9. A calibration method for a drug dissolution tester according to claim 3, characterized in that: The following steps are involved: The dissolution cup is placed in the cup hole of the water bath, and there is a clearance fit between the dissolution cup and the cup hole; Placing a calibration cover on the mouth of the dissolution vessel, wherein the calibration cover is coaxial with the dissolution vessel; Insert the stirring paddle upside down into the socket on the top cover of the frame, push the stirring paddle downward, and observe whether the paddle shaft can smoothly pass through the calibration hole of the calibration cover; If the paddle shaft can pass through the calibrated hole, the paddle is coaxial with the dissolution vessel; If the paddle shaft cannot pass through the calibration hole, a display appears on the calibration cover to indicate the offset position of the dissolution vessel; the display is divided into two parts by the center line; In an initial state, the cam is located at a first height higher than the edge of the dissolution cup; the gear ring 1 or the gear ring 2 is rotated to move at least two groups of cam assemblies to the opposite side of the development and arranged on opposite sides of the center line; Pushing the cam downward to a second height so that the cam can contact the cup edge when rotating; The cam is rotated to push the dissolution cup toward the developing side so that the calibrated hole is coaxial with the paddle shaft.

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