EP1324820B1 - Method for using a program controlled stirrer - Google Patents

Abstract

The invention relates to a program controlled stirrer for producing pharmaceutical or cosmetic recipes, comprising a stirring unit which consists of a stirring tool which engages with a mixing receptacle. According to the invention, the stirring unit is coupled to a micro-processor which determines the length of stirring time and stirring speed at the stirring unit in a program-controlled manner. The micro-processor executes a data-processing program with the following steps: input of variable data; input of constant data; determination of the length of stirring time and stirring speed in order to produce the desired amount of the recipe by combining the variable and constant data; conversion of the determined length of stirring time and stirring speed into corresponding first current or voltage values; control of the stirring unit with said first current or voltage values. Preferably, the size of the receptacle is inputted as variable data, whereby the data-processing program calculates the number of necessary rotations of the stirring tool using the constant data stored in the data memory, then controls the stirring unit correspondingly.

Description

The present invention relates to a method for using a program-controlled stirrer for the production of pharmaceutical or cosmetic formulations or the like, with a speed-controlled electrical stirrer unit which comprises a stirrer tool which engages in a mixing vessel, the stirrer unit being coupled to a microprocessor which program-controlled stirrer time and stirring speed of the stirring unit.

For example, on medical prescription, pharmaceutical and cosmetic individual formulations of ointments, powder mixtures, gels and the like are produced. In the case of the individual production of such formulations, which is usually done in pharmacies, the components of the formulation are manually mixed with one another using the conventional method. For example, mortar and pestle or glass plate and spatula can be used. In addition to the risk of contamination of the substances to be produced by the manual procedure, there is also the problem that the conditions under which the individual substances are mixed cannot be reproduced and cannot be documented. If several recipes of the same type are produced, this can result in: considerable quality differences, which can have an impact on the effectiveness of the recipe.

From DE 196 41 972 C2 a device for stirring, mixing, crushing or the like is known. Such a device (which can also be referred to as an agitator) has a stirring unit and a lifting unit in order to determine in a partially automated manner with a stirring tool in a mixing container Mix substances so that the result is the desired recipe. With this device according to the prior art, it is possible to change the stirring speed, the stirring time, the number of strokes and the lifting speed manually within certain limits in order to optimally adapt them to special types of recipes. These parameters of the agitator must be adapted to the properties of the starting materials and the respective amounts of these substances if the result of the mixing process is to be satisfactory. The disadvantage of this known device is that the optimal parameters of various mixing processes are not available over a longer period of time and therefore have to be re-entered. Individual entries of the mixing time, the number of revolutions per minute of the mixing tool, the stroke speed and the number of strokes cannot easily be reproduced at a later point in time. Special formulations can therefore vary greatly in quality both in the manufacture in different pharmacies and in the repeated manufacture in one and the same pharmacy at different times. Quality uniformity (Good Manufacturing Practice - GMP) cannot be guaranteed for the same medical prescription.

DE 39 19 534 A1 shows a method and a device for preparing bone cement. According to this method, an automatic process control is provided, the mixing phase and / or the resting phase being selected taking into account the type of the respective bone cement and its amount used. However, the operation of the device described is relatively complex since the control parameters have to be entered manually. In addition, the documentation of the mixtures carried out is not guaranteed and the Repeatability for identical mixtures cannot be guaranteed either.

A method for controlling stirring processes is known from DE 31 26 552 A1. The optimum power consumption of the agitator is regulated based on the viscosity of a substance. In addition, the viscosity can be continuously determined during the stirring process. The repeatable, documentable and rapid production of mixtures using the parameters resulting from container sizes is not important.

Finally, DE 43 02 085 C1 specifies a method for metering and mixing tooth fillers consisting of several components and a device for carrying out the method.

It is therefore an object of the present invention to minimize quality differences in the production of individual recipe albums. Another task is to simplify the use of agitators so that cosmetic and pharmaceutical products can also be manufactured in the required quality by less qualified personnel. Furthermore, the invention is intended to enable an individual formulation to be produced with the same quality even at longer time intervals and to permit an increase in effectiveness when such formulations are produced several times.

• Einlesen von variablen Daten über Dateneingabemittel, die mindestens definieren:
  • die Menge und die Kategorie der herzustellenden Rezeptur in einem vorgegebenen Toleranzbereich definieren und
  • die Größe des Mischgefäßes;
• Einlesen von konstanten Daten aus einem Datenspeicher, der für vorbestimmte Kategorien von Rezepturen und Größen von Mischgefäßen Basiswerte für die Rührzeit und die Rührgeschwindigkeit enthält;
• Ermitteln der Rührzeit und Rührgeschwindigkeit zur Herstellung der gewünschten Menge der Rezeptur durch Verknüpfung der variablen und der konstanten Daten;
• Umwandeln der ermittelten Rührzeit und Rührgeschwindigkeit in korrespondierende erste Strom- bzw. Spannungswerte und Ansteuern der Rühreinheit mit diesen Steuerparametern;
• Abspeichern der während der Herstellung der Rezeptur angewendeten Steuerparameter, gemeinsam mit Identifizierungsdaten im Datenspeicher;
• Ausgabe der angewendeten Steuerparameter und/oder Identifizierungsdaten in elektronischer und/oder gedruckter Form über Datenausgdbemittel.

These and other tasks are accomplished by a process that includes the following steps:

• Reading of variable data via data input means that define at least:
  • define the quantity and the category of the recipe to be produced within a specified tolerance range and
  • the size of the mixing vessel;
• Reading in constant data from a data memory which contains basic values for the mixing time and the mixing speed for predetermined categories of recipes and sizes of mixing vessels;
• Determining the stirring time and stirring speed for producing the desired amount of the recipe by linking the variable and the constant data;
• Converting the determined stirring time and stirring speed into corresponding first current or voltage values and controlling the stirring unit with these control parameters;
• Storing the control parameters used during the preparation of the recipe, together with identification data in the data memory;
• Output of the applied control parameters and / or identification data in electronic and / or printed form via data output means.

The main advantage of the method according to the invention is that a GMP-compliant quality uniformity of the recipes to be produced can largely be guaranteed. It is ensured that similar recipes are produced with the same mixing conditions. In addition, errors in operating the agitator are largely excluded.

• Ermitteln der benötigten Hubzahl und Hubgeschwindigkeit zur Herstellung der gewünschten Qualität der Rezeptur durch Verknüpfung der variablen und der konstanten Daten;
• Umwandeln der ermittelten Hubzahl und Hubgeschwindigkeit in korrespondierende zweite Strom- bzw. Spannungswerte;
• Ansteuern der Hubeinheit mit diesen zweiten Strom- bzw. Spannungswerten.

An advantageous embodiment of the method according to the invention is that the program-controlled agitator further contains a lifting unit by means of which the relative position of the agitating tool in the mixing vessel can be changed during the agitation process, the method comprising the following steps:

• Determining the number of strokes and stroke speed required to produce the desired quality of the recipe by linking the variable and the constant data;
• Converting the determined number of strokes and stroke speed into corresponding second current or voltage values;
• Actuation of the lifting unit with these second current or voltage values.

The inclusion of the lifting unit in the control by the microprocessor further increases the quality uniformity required by the pharmaceutical law. It also makes it possible to adapt the method of stirring to the special starting materials and the desired end product. At this point it should be noted that the term "stirring" in this context also means the comminution of the starting materials, the mixing and blending of the starting materials and all other processing operations that can be carried out by the stirring tool in the mixing vessel.

By using the program-controlled stirring tool, ointments, gels and other pasty masses can be produced. In addition, powdery individual substances can be mixed together if this is necessary for the specified recipe. Various stirring tools can be used, the size and shape of which are adapted both to the mixing vessel and to the stirring task to be performed.

According to an expedient embodiment, variable data about the viscosity of the starting materials are also read in via the data input means. If necessary, further substance-describing data or default values for the stirring time, the stirring speed, the number of strokes and the lifting speed can be entered. When using default values, the program-controlled agitator compares these default values with minimum values stored in the data memory and applies these minimum values if the default values fall below the minimum values. A gross incorrect operation of the agitator is therefore excluded, which ensures a minimum quality of the respective recipe by using the minimum values. In a modified embodiment, it is also possible to compare the default values with stored maximum values, which are also stored in the data memory.

A particularly preferred embodiment of the method enables the control parameters used during the preparation of the recipe to be stored, ie either the stirring time, the stirring speed, the number of strokes and the lifting speed or the determined current or voltage values for controlling the stirring unit and / or the lifting unit. This data is linked to individualization data, so that the control parameters used in particular can be accessed at a later point in time if an identical recipe is to be produced again. Another advantage of this measure is that it saves a considerable amount of time, since the control parameters for the agitator only have to be entered once and can be called up quickly from the data memory for later recipes of the same type.

In a further developed embodiment of the method, an output unit is also provided, via which the control parameters used and, if necessary, also the identification data can be output. For example, the identification data can be printed on a label which is attached to the packaging unit of the recipe produced. This means that the identification data are available when the used packaging unit is re-requested for the same recipe. Of course, the data can also be output in electronic form. In other embodiments, the data could be encoded in a bar code so that all control parameters can be read in again with a scanner. This would also enable the uniformity of production in different pharmacies, since not only the identification data but also the complete control data can be encoded in the bar code.

If the program-controlled agitator is set up as a stand-alone device, a keyboard, a touch-sensitive screen or a similar data input means is provided in order to feed the variable data. In a modified embodiment, there is a data connection to a personal computer which is available for data input, data output and also for data storage. The data connection can take place, for example, via a serial interface. This is particularly advantageous since conventional computers can be used in this way, which are equipped with a special control program.

Fig. 1

ein Blockschaltbild eines programmgesteuerten Rührwerks;

Fig. 2

ein Ablaufdiagramm der Anzeigen des Rührwerks während eines Mischprozesses.

Further advantages, details and further developments result from the following description of a preferred embodiment, with reference to the drawing. Show it:

Fig. 1

a block diagram of a program-controlled agitator;

Fig. 2

a flowchart of the displays of the agitator during a mixing process.

1 shows a simplified block diagram of a preferred embodiment of a program-controlled agitator. The actual mixing device consists of a stirring unit 1 and a lifting unit 2. A stirring tool is driven via these two units, which interacts with a mixing vessel. The stirring tool is adapted to the size of the mixing vessel in order to achieve optimal stirring results. The stirring tool can preferably be replaced, for example if different sizes of mixing vessels are used. Stirring unit 1 and lifting unit 2 work together in such a way that the stirring tool is rotated in the mixing vessel and that the relative position between the stirring tool and the mixing vessel changes so that the stirring tool can mix well all areas within the mixing vessel. For this purpose, it is possible both to change the vertical position of the stirring tool and to achieve the vertical movement by moving the mixing vessel when the stirring tool is stationary.

The program-controlled agitator also has a microprocessor 5, which controls the stirring unit 1 and the lifting unit 2. For this purpose, the microprocessor 5 executes a data processing program, the individual method steps of which are explained in more detail below. The control data supplied by the microprocessor 5 for the stirring unit 1 and the lifting unit 2 are converted in a conventional manner into current or voltage values, for which purpose known circuit elements (not shown) are used. The microprocessor 5 can access a data memory 7 in order to load predetermined constant data and / or to store determined control data for a later mixing process. Furthermore, the microprocessor 5 interacts with data input means 8 and data output means 9. Variable data can be entered by the user via the data input 8. In particular, the user can specify the amount of the recipe to be produced (for example a suspension ointment), the desired stirring time and the desired number of revolutions of the stirring tool. Advantageously, there are input options for the size of the mixing vessel used, so that the optimum control values for the agitator can be determined from this information. The microprocessor 5 links the variable data entered via the data input means 8 with the constant data which are stored in the data memory 7. The variable data are compared with minimum values and with maximum values, which specify the possible limit values for the stirring speed, the stirring time, the lifting speed and the number of strokes.

It should be noted that the stirring process does not have to be carried out with constant control values over the entire time. Rather, it makes sense for certain substances to start with a slow stirring speed and then to continue with a higher speed of the stirring tool to achieve optimal mixing results. After a so-called rubbing process, the speed of the stirring tool can be increased in order to produce a uniform mixing as quickly as possible.

The microprocessor 5 can output the control parameters used via the data output means 9. The data output means 9 can comprise a display which shows both the current operating state and the control parameters to be used during the mixing process. In addition, a printer or an external data storage device can be assigned to the data output means 9 in order to store the control parameters in printed form, for example on the label of the recipe produced, or on external electronic data storage devices for later use.

2 shows a sequence of reproductions of a display unit of the data output means during a mixing process which is carried out by the program-controlled agitator. Based on this display sequence, the essential steps that the program-controlled agitator carries out are explained below, the control of these method steps being carried out by the data processing program that is executed on the microprocessor.

In the example shown, a suspension ointment with an amount of 50 ml is to be produced. In step 10, the display is shown when the data entry is complete. The agitator is first put into operation and the required data is entered by the user via the data input means in step 11. At least the amount of the suspension ointment to be produced is to be entered, with additional data optionally being able to be entered, for example the desired duration of the stirring process. On the basis of the data stored in the data memory, however, the data processing program is able to independently determine all further data from the amount of the recipe to be produced. In this case, stored default values for the stirring time, the stirring speed, the lifting speed and the number of strokes are used. The manufacturer of the program-controlled agitator can permanently read the default values into the data memory. However, there is also the possibility that the default values can be saved by the user in a programming mode if this appears expedient for certain applications. In addition, the recipe number and, if necessary, a batch name can be entered or specified by the data processing program. Such data are used as identification data, which enable the mixing process carried out to be clearly assigned to the control parameters used. All essential data are encoded in the batch name, for example the type of recipe (normal, emulsion, suspension, reaction mixture, powder or the like) and special specifications for the stirring process (e.g. with grinding process in the manufacture of suspensions).

When all the specification data has been entered and the missing data required for controlling the mixing process has been determined by the data processing program in step 12, the mixing process begins. In the example shown, the mixing process begins with a grinding process, which is also indicated in the batch designation by the "AR" indicator. Step 20 shows the display that appears during the rubbing process. The speed of rotation is also displayed, which is matched to the special type of product to be manufactured. In the present The case is 1,000 revolutions per minute (rpm). The number of revolutions and the number of strokes carried out as well as the remaining mixing time are also specified.

After completion of the grinding process, the "normal" mixing process begins and the display changes to the state shown in step 30. The current speed of rotation, the number of revolutions to be carried out, the number of strokes to be carried out by the agitator and the remaining time for the current mixing process are also displayed here. In parallel to the displays, the control parameters used are stored and / or output in step 31, for example encrypted in the identification data and printed on a label. After the mixing process is complete, the display returns to step 10 so that the user can also check the correct completion of the recipe in the display. Of course, it is also possible to generate a changed final display in which the user is informed in a summarized form of the successful completion of the mixing process.

In the case of modified embodiments, a final rapid homogenization process can take place after a first mixing section. In this way, the total time for the preparation of the recipe can be significantly reduced.

It is also useful to document the number of mixing operations performed and the resulting operating time of the agitator in the data memory and to have them available for maintenance operations. In this way, the user can be shown at the right time that maintenance of the agitator is now required, which increases the maintenance intervals lie in an optimal period of time, so that the service life of the agitator is increased and functional reliability is always guaranteed.

Since a corresponding agitator is preferably equipped with specially predetermined mixing vessels (so-called jars), a certain number of revolutions that the mixing tool has to carry out can be specified for each size of a mixing vessel. It is therefore sufficient if the user feeds the jar size via the data input means.

In modified embodiments, sensors are attached which automatically detect the jar size, so that this data entry is also automated without any direct action by the user.

Claims (10)

1. A method for utilizing a program-controlled agitator for producing pharmaceutical or cosmetic recipes or the like, with a speed-controlled electric agitating unit (1) containing an agitating tool that engages into a mixing vessel, wherein the agitating unit is connected to a microprocessor (5) that defines the agitating time and agitating speed of the agitating unit (1) in a program-controlled fashion, and wherein the method comprises the following steps:

   · reading in (11) variable data by means of data input means (8), wherein the variable data defines at least

   - the quantity and the category of the recipe to be produced within the predefined tolerance range, and

   - the size of the mixing vessel;

   · reading in (11) constant data from a data memory (7) that contains basic values for the agitating time and the agitating speed for predetermined categories of recipes and mixing vessel sizes;

   · determining (12) the agitating time and the agitating speed for producing the desired quantity of the recipe by linking the variable data with the constant data;

   · converting the determined agitating time and agitating speed into corresponding first current or voltage values and controlling the agitating unit with these control parameters;

   · storing the control parameters used during the production of the recipe in the data memory (7) together with identification data, and

   · outputting the control parameters used and/or the identification data in electronic and/or printed form with the aid of data output means (9).
2. The method according to Claim 1, wherein the program-controlled agitator also contains a lifting unit (2) for varying the relative position of the agitating tool in the mixing vessel during the agitating process, and wherein the method also comprises the following steps:

   · determining the optimal lifting frequency and lifting speed for producing the desired quality of the recipe by linking the variable data with the constant data;

   · converting the determined lifting frequency and lifting speed into corresponding second current or voltage values, and

   · controlling the lifting unit with these second current or voltage values.
3. The method according to Claim 1 or 2, wherein the method also comprises a step in which the number of required revolutions of the agitating tool is determined by utilizing the variable data and the constant data.
4. The method according to one of Claims 1 to 3, wherein the method also comprises a step in which the viscosity of the starting material is read in in the form of variable data.
5. The method according to one of Claims 2 to 4, wherein the method also comprises the following steps:

   · supplying default values for the agitating time, the agitating speed, the lifting frequency and the lifting speed in the form of additional variable data;

   · comparing these default values with predetermined minimum values that are also stored in the data memory, and

   · utilizing the minimum values for the agitating time, agitating speed, lifting frequency and lifting speed if the default values are smaller than the minimum values.
6. The method according to one of Claims 2 to 5, wherein the method also comprises a step in which the maximum agitating time, agitating speed, lifting frequency and lifting speed of the agitator are stored in the data memory (7) in dependence on the quantity and viscosity of various starting materials.
7. The method according to Claim 1, wherein the method also comprises the following steps:

   · encoding all control parameters and/or identification data in a barcode, and

   · outputting the encoded control parameters in the form of a printout on a label of the package containing the produced recipe.
8. The method according to Claim 1, wherein the method also comprises the following steps:

   · reading in a recipe identification in the form of variable data;

   · reading in the control parameters, the identification data of which corresponds to the recipe identification, from the data memory, and

   · utilizing the stored control parameters for controlling the agitating unit and the lifting unit

   such that the new recipe is produced with the same parameters as those used for producing the same recipe at an earlier time.
9. The method according to one of Claims 1 to 8, wherein the variable data is read in by means of a personal computer that is connected to the agitator via a data circuit, and wherein the control parameters are stored in a data memory (7) provided in this personal computer.
10. The method according to one of Claims 1 to 9, wherein the method also comprises a step in which the size of the mixing vessel and/or the quantity of the starting material is automatically determined with the aid of sensors.