GB2449150A

GB2449150A - Dissolution test arrangement using air heated jacket

Info

Publication number: GB2449150A
Application number: GB0804218A
Authority: GB
Inventors: Franz Faehler
Original assignee: PHARMA TEST APPBAU GmbH
Current assignee: PHARMA TEST APPBAU GmbH
Priority date: 2007-03-06
Filing date: 2008-03-06
Publication date: 2008-11-12
Also published as: GB0804218D0; CH701157B1; DE102007011449A1; DE102007011449B4

Abstract

An arrangement to test the breakdown period and active ingredient release of a test substance comprises at least one heatable testing vessel 1 for the test solution, a mixer and an elevation and control unit. The testing vessel is surrounded by a cladding jacket 3 such that a gap 2 is formed between the jacket and the wall of the testing vessel. At least one heating means being a light-heat source 4, a glass heating element and Peltier element or a ceramic is attached below the testing vessel. In use, air is heated by the heating element and flows through the gap from an inlet 8 to an outlet 9 to heat the testing vessel. Preferably, the cladding jacket is attached to a base element 6 of a housing 16 which holds the light-heat source. Further, a disc 5 may be provided as a cover for the light-heat source wherein the disc is made of ceran or red-coloured glass which shields the visible light, or may be a metal disc.

Description

PMA 107 GB Arrangement for testing the breakdown period and the active

ingredient re-lease of test substances in liquids The invention is for an improved arrangement for testing of the breakdown period and active ingredient release of test substances in liquids such as those used in dissolution test devices.

The improvement is especially beneficial for the process of decomposition testing substances in solid, semi-solid or transdermal forms of application and the release of the active ingredients contained in the testing substances.

For the testing of the breakdown rate and the release of the active ingredient of test substances, the decomposition processes, in particular the rate decomposition and the technique used in the respective devices, are especially important.

Known devices for testing the decomposition rate or the release of the active ingredient have a testing vessel or a number of testing vessels with a test solution in which the test substance is placed. By means of a mixing element or a basket which holds the test substance and goes u and down and a rpm or hub speed stipulated for the decomposition process, a pre-set time and temperature established for the test solution, for instance, human body temperature, the decomposition process for the test substance is conducted. Periodically, samples are taken during this period to be able to determine the degree of decomposition of the test substance and the release of the active ingredient.

In conventional devices the testing vessel with the test solution is placed in a water-bath and the temperature of the water-bath is generally regulated by some type of known external water-pump heating device. The water is continuously circulated between the water-bath and the heating device until in this manner the stipulated temperature of the test solution is attained and then the level can be maintained.

Such heating systems generally require a long warm-up period and not only have to be cleaned of algae on a regular basis, but also must be refilled because of the evaporation of water.

From US patent 4,754,657 it is know that the heating of the test solution can be achieved with heating elements integrated in the chamber walls of the testing device.

US patent 3,109,913 shows a decomposition testing device in which the both the heating element and a thermostat are attached in the sleeve shaft of a mixer.

To eliminate the disadvantages associates with this, the European patent EP 0 746 750 Bi describes a device for testing the decomposition of substances in which the testing vessel has a mixing element with a sleeve shaft for which a heating element, in particular a heating cladding jacket is attached to the outside of the testing vessel and within the mixing element there is a temperature sensor for regulating the temperature with the corresponding signals for controlling the heating element.

The state of art engineering solutions for heating and maintaining constant temperatures of the testing solutions are, besides being relatively expensive, also subject to breakdown and expensive to maintain.

The task of the invention is therefore to provide an arrangement for testing the decomposition time and the release of active ingredients of test substances in fluids in a heating device that is improved and less prone to breakdowns.

The invention accomplishes the task by arranging the testing of the decomposition time and the release of the active ingredient of a test substance with at least one heatable test vessel for a test solution, a mixing element and an evaluation and control unit in which the test vessel is surrounded by a cladding jacket so that there is a gap between the wall of the cladding jacket and the wall of the test vessel, below the test vessel there is at least one light-heating source, a glass heating element, a Peltier element or a ceramic heater and for the air heated by the light-heating source, glass heating element, Peltier element or ceramic heater which flows through the gap there is an input and an output.

The invention combines the special advantage that an elegant, trouble-free and low-maintenance technical solution is provided which allows the visual inspection of the test vessel and therefore of the decomposition process of the test substance and is also inexpensive to produce. This allows a contact-free heating source for heating the test solution. In addition, it is associated with low energy costs. The heat sources used for heating the test vessel can also be exchanged without any problems.

Special forms of execution of the invention have a cladding jacket, preferably sealed and on a base element of a housing to hold the light-heat source.

A special form of execution of the invention foresees at least one temperature sen-sor in or on the test vessel connected with the evaluation and control unit.

Another execution of the invention foresees that a disk is placed between the test vessel and the light-heat source, preferably on the base element or as a cover on the light-heat source.

In another form of execution of the invention the disk which shields the visible light in the wavelength of 380 nm to 780 nm is made of glass-ceramics or red colored glass or the disk is metal.

In a special execution of the invention foresees attaching a vertical shaft below the test vessel with the upper end protruding through the disk and a sensor on this end which records the positioning of the test vessel and is attached to the evaluation and control unit.

Other forms of execution of the arrangement attached the light-heat source to the shaft by means of a holding element and the height can be adjusted.

The cladding jacket and the test vessel consist in another form of execution of transparent and light-resistant plastic, preferably made of acrylate glass, especially preferred is polymethylmethacrylate or a polycarbonate plastic, especially preferred from poly[oxycarbonyloxy-1,4-phenylen-( 1 -methylethyliden)-1,4-phenylen].

In other forms of execution the invention has 3 light-heat sources, whereby these are attached in an angle of almost 500 to vertical.

In other forms of execution the invention has 3 light-heat sources, which might be an infrared heater or halogen lamps, for instance.

The halogen lamps and the infrared heater preferably each have a strength of 20 watts to 75 watts, whereby the maximum emission of the infrared heater is at a wavelength in the range of 0.75 pm to 2.2 pm.

And finally, to attain an improved heating effect in the housing, a heat circulating device is planned.

The invention is to be explained in detail on the basis of drawings: Fig. I The side view of an invented arrangement; Fig. 2 The arrangement as per Fig. I in the cross-section C-C; Fig. 3 The side view of the arrangement as per Fig. I in the cross-section D-D; Fig. 4 An invented arrangement in perspective presentation; Fig. 5 The top view auf the arrangement; Fig. 6 The arrangement as per Fig. 5 in the cross- section A-A; Fig. 7 The perspective presentation of several invented arrangements held by a frame; Fig. 8 The top view of the presentation as per Fig. 7 Fig. 9 The side view the arrangement as per Fig. 8.

Figure 1 shows a side view of an invented arrangement and that with the cladding jacket 3 from the test vessel 1, for holding the test solution of the test substance and a mixing device protruding which is not shown here. The cladding jacket 3 is at-tached to the base element 6. Between the cladding jacket 3 and the base element 6 there is the light filter disk 5, positioned with the aid of the pins 19. Between the cladding jacket 3 and the light filter disk 5 a ring-shaped disk may be attached as needed. The electrical power supply connection 12 can be clearly seen.

Figure 2 shows the arrangement as per Fig. I in the cross-section C-C. This form of execution of the invention has 3 light-heat sources 4, which are attached to the shaft by means of a holding element 11. Instead of the light-heat sources 4 and the light filter disk 5 a glass-heating element, for instance, such as is available as Pow-ergias , can be used. The glass-heating element is best positioned on the base element 6 of the housing 16.

Figure 3 shows the side view the arrangement as per Fig. I in the cross-section D-D. The gap 3 formed by the space between the wall of the cladding jacket 2 and the wall of the test vessel 1 is where the heated air from the light-heat source 4 may rise, It has been proven that the distance between the wall of the cladding jacket 3 and the wall of the test vessel 1 is about 3 mm to 10 mm.

As light-heat source 4 in this form of execution 25 Watt halogen lamps are used which are attached to the shaft 10 shaped as a spindle or splined shaft 10 with the holding element 11 and can be adjusted in the height. To adjust the height of the light-heat source 4 a motor may be used. The cladding jacket 3 sits on the base element 6, whereby the light filter disk 5 is also attached to the two with washers.

The cladding jacket 3 and the light filter disk 5 are positioned by means of the pins 19. The light filter disk 5 serves to absorb light which is damaging for the test sub-stance during the test, It has been shown to be recommendable to use a light filter disk 5 consisting of glass-ceramics or a red-colored glass with a strengths 3 mm to 5 mm. The light fi!ter disk 5 can be attached as a cover of the light-heat sources 4, so that the disk 5, otherwise positioned on the base element 6, is no longer needed.

In other forms of execution of the invented arrangement infrared heat sources 4 can also be used as the light-heat source. In this case it is not necessary to use the light filter disk 5.

An additional forrri of execution foresees a metal disk which also has vents 8 instead of the tight filter disk 5.

At the top end of the shaft 10, through which the light filter disk 5 protrudes, the sen-sor 7 is attached which records the positioning of the test vessel 1 and is electrically connected to the evaluation and control unit by means of the connection 20. As sen-sor 7 a magnetic Elobau 122 (G092.800) proximity switch may be used. With the aid of the sensor 7 it is guaranteed that the light-heat source 4 is only activated when the test vessel I is in the position planned for the test.

As soon as the light-heat sources 4 are activated, air can enter through the openings 8, which is heated by means of the light-heat sources 4 and can rise up through the openings (not shown here) in the light filter disk 5 into the gap 2 formed by the space between the cladding jacket 3 and test vessel I and thereby heat the test vessel I with the test solution. The heated air can escape through an exit opening 9.

The exit openings 9 for the air may also be distributed round the upper edge of the cladding jacket 3. In such a case the angled edge 18 of the test vessel I sits directly on the cladding jacket 3.

To determine the specific temperature the wall of the test vessel 1 -not shown here -has at least one contact surface with one temperature measuring sensor each.

The heat conductor NTCs Epcos B57017-K (EI11.000) may, for instance, be used as the temperature measuring sensor; this is suitable for regulating temperatures in the range of 200 C to 45 C. The temperature of the test fluid may, however, also be determined by means of a temperature measurer attached to test vessel 1.

Figure 4 shows an invented arrangement in perspective presentation with the test vessel 1 positioned on the shaft 10, the cladding jacket 3 and the pins 19, with whose aid the cladding jacket 3 and the light filter disk 5 are positioned on the base element 6. The inlets 8 for the air to be heated are clearly visible.

The cladding jacket 3 and the test vessel 1 are made of a transparent and light-resistant polycarbonate plastic, in this execution a material known with the trade name Makrolon . An acrylic glass such as Plexiglas is also suitable.

Figure 5 shows a top view of the new arrangement with a number of inlets 8 for the air. The arrangement has 3 light-heat sources 4, which are attached to the shaft 10 by means of the holding element 11.

In Figure 6 the arrangement as per Fig. 5 is shown in the cross-section. Fig. 6 shows that the light-heat sources 4 are in an angle of 50 to the shaft 10, which is shaped as a spindle here and that they can be adjusted in the height.

Figures 7, 8 and 9 show a number of invented arrangements in perspective presen-tation and in a side view and a top view.

In the stand 17 with the housing 16 and the spacers 14 and the support plate 15 a total of 8 invented arrangements are planned. The light-heat sources 4 are in the housing 16-. not shown here. The test vessel 1 and the cladding jacket 3 can be securely positioned by means of the locking elements 13. To obtain a quicker heat-ing an air circulator may be mounted in the housing 16.

The expert realizes that a number of changes in the specifics, the materials and the constructive arrangement of the individual elements can be made to the invention as it is shown and described without leaving the realm of the invention as it is documented in the patent claims. It is clear that the invented arrangement can also use other light-heat sources 4 and also other technical solutions for adjusting the height of the light-heat sources 4 than those shown.

LIST OF REFERENCES IN ILLUSTRATIONS

1 Testing vessel 2 Gap 3 Cladding jacket 4 Light-heat source Light filter wafer 6 Base element 7 Sensor 8 Inlets 9 Outlets Shaft 11 Holder 12 Electrical supply connections 13 Locking element 14 Spacer Support plate 16 Housing 17 Stand 18 Edge 19 Pin Connection for evaluation and control unit

Claims

Arrangement to test the breakdown period and the active ingredient release of a test substance with at least one heatable testing vessel (1) for the test solution, a mixer and an evaluation and control unit, characterized by the testing vessel (1) being surrounded with a cladding jacket (3) in such a man- ner that between the wall of the cladding jackets (3) and the wall of the test-ing vessel (1) a gap (2) is formed, below the testing vessel (1) at least one light-heat source (4), a glass heating element, a Peltier element or a ceramic is attached and inlet (8) and outlets (9) are provided for the air to be heated by the light-heat source (4), of the glass-heating element, the Pettier element or the ceramic heater, flow through the gap (2).
2. Arrangement as per claim 1, characterized by the cladding jacket (3) at-tached to a base element (6) of a housing (16), which holds the light-heat source (4) and preferably with a gasket between the cladding jacket (3) and base element (6).
3. Arrangement as per claim 1, characterized by the glass-heating element below the testing vessel (1), preferably attached to the base element (6).
4. Arrangement as per claim 1, characterized by am testing vessel (1) or in-side of the testing vessel (1) at least one temperature sensor is attached to the evaluation and control unit.
5. Arrangement as per claim 1, characterized by between the testing vessel (1) and the light-heat source (4), preferably attached to the base element (6), or a disk (5) as a cover for the light-heat source (4).
6. Arrangement as per claim 5, characterized by the disk (5) a disk made of ceran or red-colored glass, which shields the visible light in the wavelength range from 380 nm to 780 nm, or is a metal disk.
7. Arrangement as per claims 1 to 6, characterized by a shaft (10) is attached vertically below the testing vessels (1) and its upper end protrudes up through the disk (5) and on this end there is a sensor (7), which records the position of the testing vessels (1) and is connected to the evaluation and control unit.
8. Arrangement as per claims 1, 2 or 4 to 6, characterized by the light-heat source (4) being attached to the shaft (10) by means of a holding element (11).
9. Arrangement as per claim 8, characterized by the light-heat source (4) be-ing attached to the shaft (10) in a manner that the height can be adjusted.
10. Arrangement as per claim 1 or 2, characterized by the cladding jacket (3) and the testing vessel (1) being made out of a transparent and light-resistant plastic preferably an acrylate glass, especially a polymethylmethacrylate or a polycarbonate plastic, especially of poly[oxycarbonyloxy-1,4-phenylen-(1 -methylethyliden)-1,4-phenylen].
11. Arrangement as per claims 1, 2, 5, 6, 8 or 9, characterized by it having 3 light heat sources (4).
12. Arrangement as per claims 1, 2 and 5, 6, 8, 9 or 10, characterized by the light-heat source (4) attached at a 500 angle to vertical.
13. Arrangement as per claims 1, 2, 4, 7, 8, 10 or 11, characterized by the light-heat source (4) being an infrared light or a halogen bulb.
14. Arrangement as per claims 1, 2, 5, 6, 8,9 or 11 to 13, characterized by the halogen-bulb and the infrared light having a power of 20 watts to 75 watts each and that the maximum emission of the infrared source has a wave-length in the range of 0.75 pm to 2.2 pm.
15. Arrangement as per claims I to 14, characterized by an air-circulation de-vice being foreseen in the housing (16).