Liquid degassing device

Abstract

A liquid degassing device comprises an infusion pump (1), a degassing lung (2), an on-line dissolved oxygen sensor (3), a tee joint (4), a first two-way valve (5), a second two-way valve (6) and a controller (7), the infusion pump (1) is connected with the degassing lung (2), the degassing lung (2) is connected with the on-line dissolved oxygen sensor (3), the tee joint (4) is connected with the on-line dissolved oxygen sensor (3), the first two-way valve (5) and the second two-way valve (6), and the controller (7) is connected with the controller (7). The liquid degassing device disclosed by the utility model has the advantages of qualified degassing, accurate distribution, easiness in cleaning, high automation degree and the like.

Description

Technical Field

[0001] The invention relates to a liquid degassing device, belongs to the fields of medicine and food, and in particular to a degassing, preheating and distributing device for a dissolution medium used in a dissolution test. Background Art

[0002] Dissolution rate refers to the rate and extent of dissolution of active drug ingredients from tablets, capsules, or granules under specified conditions. It is a key indicator for evaluating the quality of oral solid dosage forms and an in vitro evaluation method that simulates the disintegration and dissolution of oral solid dosage forms in the gastrointestinal tract. A dissolution apparatus provides a microcomputer-controlled, mechatronic test device for dissolution testing. It primarily consists of a motor, a constant temperature water bath, a basket, a stirring paddle, a dissolution cup, and a cup lid.

[0003] In the dissolution test, an accurate volume of dissolution medium (such as pure water, simulated gastric fluid, buffer solutions of different pH values, etc.) is placed in the dissolution cup and the dissolution apparatus is turned on. When the temperature of the dissolution medium in the dissolution cup reaches the test set temperature, the drug is added and then stirred. At a specified time point, a certain volume of drug solution is extracted from the dissolution cup for testing to evaluate the dissolution rate and extent of the drug.

[0004] Pharmacopoeias require that the dissolution medium must be degassed, that the measured volume must not deviate from the specified volume by more than ±1%, that the temperature must not deviate from the target temperature by more than ±0.5°C, and that the dissolution medium should be within ±0.05 of the target pH. Dissolution apparatus calibration procedures require that the dissolved oxygen content in the dissolution medium not exceed 2.8 mg / L.

[0005] There are two types of degassing machines for dissolution media: closed heating vacuum degassing and online degassing. However, both degassing machines only execute the set program and cannot guarantee the final degassing effect. For heating vacuum degassing machines, such as heating to 80 degrees for 30 minutes and vacuum degassing for 1 hour, for online degassing machines, the degassing effect is improved by cascading multiple degassing lungs so that the expected degassing effect can basically be achieved. As for whether the set dissolved oxygen standard can be achieved, there is no guarantee and it can only be determined by experience. Due to the variety of dissolution media, some even add a certain proportion of organic phase or surfactant, the initial dissolved oxygen content of different solvents is different, and the degassing difficulty also varies. The above treatment method cannot be guaranteed to be applicable to all dissolution media. If it needs to be determined, a special dissolved oxygen meter is also needed for measurement. If it does not meet the standard, degassing needs to be carried out again, which is extremely cumbersome. Summary of the Invention

[0006] In view of the above-mentioned defects of the existing treatment methods, the purpose of the present invention is to provide a liquid degassing device that can circulate and degas the dissolution medium until it meets the set dissolved oxygen standard, and then perform distribution, thereby ensuring that the distributed dissolution medium is a dissolution medium that meets the standard and the distribution amount is accurate.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A liquid degassing device comprises an infusion pump (1), a degassing lung (2), an online dissolved oxygen sensor (3), a three-way valve (4), a first two-way valve (5), a second two-way valve (6) and a controller (7), wherein the infusion pump (1) is connected to the degassing lung (2), the degassing lung (2) is connected to the online dissolved oxygen sensor (3), the three-way valve (4) is connected to the online dissolved oxygen sensor (3), the first two-way valve (5) and the second two-way valve (6), and the controller (7) performs cyclic degassing, distribution, calibration, cleaning and emptying operations according to a user-set program.

[0009] Preferably, the liquid degassing device further comprises a plurality of additional degassing lungs, and the degassing effect is improved by cascading the degassing lungs.

[0010] Preferably, the liquid degassing device further comprises a weighing balance (8) and a weighing container (9), wherein the weighing balance (8) and the weighing container (9) are located after the second two-way valve (6) and perform weight measurement on the distributed medium.

[0011] Preferably, the liquid degassing device further comprises a flow meter (10), which is located between the online dissolved oxygen sensor (3) and the tee (4), and measures the flow rate in the intermediate stage of dispensing (stable without bubble influence), and calculates the density of the liquid in combination with the weight measurement during the same time, and calculates the target weight representing the target volume, so that the accurate volume of dissolution medium is dispensed.

[0012] Preferably, the liquid degassing device further comprises a heating body (11), which is located between the online dissolved oxygen sensor (3) and the flow meter (10) and preheats the dissolution medium during distribution to accelerate the equilibrium of the dissolution apparatus.

[0013] Preferably, the infusion pump (1) is a peristaltic pump that can perform forward and reverse rotations to clean the system in both forward and reverse directions, thereby improving the cleaning effect.

[0014] Preferably, the liquid degassing device can also perform an automatic calibration procedure for the online dissolved oxygen sensor (3), by pumping in a zero calibration liquid, performing a zero calibration, then replacing the purified water, cleaning the system, and performing a full scale calibration after properly emptying it.

[0015] Preferably, the liquid degassing device adjusts the speed of the infusion pump (1) through a proportional-integral-differential (PID) weight closed-loop algorithm to make the distribution more accurate.

[0016] Preferably, the heating body (11) adjusts the heating power through a fuzzy PID algorithm so that the output liquid reaches the target set temperature.

[0017] The three-way valve (4), the first two-way valve (5) and the second two-way valve (6) can be replaced by a three-way valve. Beneficial effects

[0018] (1) Online circulating degassing to ensure that the dissolution medium after degassing meets the set standards.

[0019] (2) Accurate dispensing: By combining the flow rate and weight in the intermediate stage of dispensing, which is least affected by bubbles, the liquid density is automatically calculated. Quantitative dispensing is performed by weight plus density correction combined with PID, with an accuracy of ±0.4 mL. For the minimum dissolution medium of 250 mL, the error is only ±0.16%, which far exceeds the dissolution medium volume error requirements (±1%) required by the United States Pharmacopoeia and the Chinese Pharmacopoeia.

[0020] (3) Preheating the dissolution medium saves the equilibration time of the dissolution apparatus. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of Example 1 of the liquid degassing device of the present invention

[0022] In the figure: 1. Infusion pump, 2. Degassing lung, 3. Online dissolved oxygen sensor, 4. Three-way valve, 5. First two-way valve, 6. Second two-way valve, 7. Controller, 8. Weighing balance, 9. Weighing container, 10. Flow meter, 11. Heating element, 12. Liquid inlet, 13. Liquid return port, 14. Vacuum pump, 15. Distribution port. DETAILED DESCRIPTION

[0023] The preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Example

[0024] like Figure 1 As shown, a liquid degassing device includes an infusion pump, a degassing lung, an online dissolved oxygen sensor, a three-way valve, a first two-way valve, a second two-way valve, a controller, a weighing balance, a weighing container, a flow meter, and a heating body.

[0025] The working procedure of the liquid degassing device is as follows:

[0026] Circulation degassing: the first two-way valve (5) is opened, the second two-way valve (6) is closed, the vacuum is drawn to the set threshold and maintained, the infusion pump (1) runs in the forward direction, the dissolution medium is drawn out through the degassing lung and circulated back to the container containing the dissolution medium, the reading value of the online dissolved oxygen sensor (3) is read from time to time, and when the reading value reaches the target set standard, the infusion pump (1) stops working and releases the vacuum.

[0027] Distribution: The controller (7) controls the weighing scale (8) to return to zero, the first two-way valve (5) is closed, the second two-way valve (6) is opened, and the infusion pump (1) runs forward. At the same time, the controller (7) controls the heating power of the heating body (11) through the PID algorithm. When the weighing scale (8) measures to 1 / 3 of the target weight (based on an approximate density of 1), the timing is started and the current weight is recorded. When the weighing scale (8) measures to 2 / 3 of the target weight (based on an approximate density of 1), the timing is stopped and the current weight is recorded. During this period, the real-time flow rate is recorded. The density of the liquid is calculated by the weight difference and the average flow rate, thereby calculating the accurate target weight. The controller (7) controls the speed of the infusion pump (1) through the PID weight closed-loop algorithm until the target distribution weight is reached.

[0028] Calibration: prompt the user to place the zero point standard solution, close the first two-way valve (5), open the second two-way valve (6), and run the infusion pump (1) in the forward direction to fill the online dissolved oxygen sensor (3) with the zero point standard solution. The controller (7) controls the online dissolved oxygen sensor (3) to perform zero point calibration. Stop the infusion pump (1), prompt the user to place purified water, run the infusion pump (1) in the forward direction to fully clean the online dissolved oxygen sensor (3). Run the infusion pump (1) in the reverse direction to drain the online dissolved oxygen sensor (3). The controller (7) controls the online dissolved oxygen sensor (3) to perform full scale calibration.

[0029] Cleaning: First, the first two-way valve (5) is closed, the second two-way valve (6) is opened, and the infusion pump (1) is run in the forward direction to clean the distribution pipeline. Secondly, the first two-way valve (5) is opened, the second two-way valve (6) is closed, and the infusion pump (1) is run in the forward direction to clean the return liquid pipeline. Finally, the infusion pump (1) is run in the reverse direction to perform reverse cleaning. This is repeated to perform cyclic cleaning.

[0030] Emptying: First, the first two-way valve (5) is closed, the second two-way valve (6) is opened, and the infusion pump (1) runs in the forward direction to empty the distribution pipeline. Secondly, the first two-way valve (5) is opened, the second two-way valve (6) is closed, and the infusion pump (1) runs in the forward direction to empty the return pipeline. Finally, the infusion pump (1) runs in the reverse direction to perform reverse emptying.

Claims

1. A liquid degassing device, characterized in that: The invention comprises an infusion pump (1), a degassed lung (2), an online dissolved oxygen sensor (3), a three-way valve (4), a first two-way valve (5), a second two-way valve (6) and a controller (7), wherein the infusion pump (1) is connected to the degassed lung (2), the degassed lung (2) is connected to the online dissolved oxygen sensor (3), and the three-way valve (4) is connected to the online dissolved oxygen sensor (3), the first two-way valve (5) and the second two-way valve (6).

2. A liquid degassing device according to claim 1, characterized in that: The liquid degassing device further comprises a plurality of degassing lungs, and the degassing effect is improved by cascading the degassing lungs.

3. A liquid degassing device according to claim 1 or 2, characterized in that: The liquid degassing device further comprises a weighing balance (8) and a weighing container (9), which are located after the second two-way valve (6) and perform weight measurement on the distributed medium.

4. A liquid degassing device according to claim 3, characterized in that: The liquid degassing device further comprises a flow meter (10), which is located between the online dissolved oxygen sensor (3) and the tee (4). The flow meter can measure the flow rate in the intermediate stage of distribution, and calculate the density of the liquid in combination with the weight measurement at the same time, and calculate the target weight representing the target volume, so that the accurate volume of dissolution medium can be distributed.

5. A liquid degassing device according to any one of claims 1 to 4, characterized in that: The liquid degassing device further comprises a heating body (11), which is located between the online dissolved oxygen sensor (3) and the flow meter (10) and preheats the dissolution medium during distribution to accelerate the equilibrium of the dissolution apparatus.

6. A liquid degassing device according to any one of claims 1 to 5, characterized in that: The three-way valve (4), the first two-way valve (5) and the second three-way valve (6) are replaced by a three-way valve.

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