Device and method for determining the weight of pharmaceutical products by means of an x-ray source

Abstract

The invention relates to a device ( 10; 10 a ) for determining the weight of pharmaceutical products ( 1 ), in particular of hard gelatin capsules ( 3; 3 a ) filled with a pharmaceutical ( 2 ), by means of an X-ray source (28), wherein the X-ray source ( 28 ) generates a radiation cone ( 27; 36, 37 ) which passes through at least one pharmaceutical product ( 1 ), and wherein a sensor element ( 30; 30 a ) detects the radiation of the irradiated pharmaceutical product ( 1 ) and supplies an evaluation device ( 32 ). According to the invention, a reference object ( 35; 35 a; 35 b ) is arranged in the beam path of the radiation cone ( 27; 36, 37 ), wherein the radiation of the X-rayed reference object ( 35; 35 a; 35 b ) is detected by means of the sensor element ( 30; 30 a; 30 b ) and is supplied to the evaluation device ( 32 ), and wherein the pharmaceutical product ( 1 ) and the reference object ( 35; 35 a; 35 b ) are positioned in relation to the radiation cone ( 27; 36, 37 ) in an arrangement in which they do not overlap each other in the radiation cone ( 27; 36, 37 ).

1 . A device ( 10 ;  10   a ) for determining the weight of pharmaceutical products ( 1 ), by means of an X-ray source ( 28 ), wherein the X-ray source ( 28 ) generates a radiation cone ( 27 ;  36 ,  37 ) which passes through at least one pharmaceutical product ( 1 ), and wherein a sensor element ( 30 ;  30   a ) detects radiation of the irradiated pharmaceutical product ( 1 ) and supplies an evaluation device ( 32 ), characterized in that a reference object ( 35 ;  35   a ;  35   b ) is arranged in a beam path of the radiation cone ( 27 ;  36 ,  37 ), wherein radiation of the X-rayed reference object ( 35 ;  35   a ;  35   b ) is detected by the sensor element ( 30 ;  30   a ;  30   b ) and is supplied to the evaluation device ( 32 ), and wherein the pharmaceutical product ( 1 ) and the reference object ( 35 ;  35   a ;  35   b ) are positioned in relation to the radiation cone ( 27 ;  36 ,  37 ) in an arrangement in which the pharmaceutical product and the reference object do not overlap each other in said radiation cone ( 27 ;  36 ,  37 ). 
     
     
         2 . The device according to  claim 1 , characterized in that the sensor element is an image recording sensor element ( 30 ;  30   a ;  30   b ). 
     
     
         3 . The device according to  claim 1 , characterized in that a material of the reference object ( 35 ;  35   a ;  35   b ) has a similar atomic composition as the pharmaceutical product ( 1 ). 
     
     
         4 . The device according to  claim 1 , characterized in that the reference object ( 35 ;  35   a ;  35   b ) is arranged in the same plane ( 39 ) as the pharmaceutical product ( 1 ). 
     
     
         5 . The device according to  claim 1 , characterized in that the reference object ( 35 ;  35   a ;  35   b ) has different thicknesses in a plane perpendicular to the radiation cone ( 27 ;  36 ,  37 ). 
     
     
         6 . The device according to  claim 5 , characterized in that the reference object ( 35   a ,  35   b ) is designed wedge-shaped or in steps. 
     
     
         7 . The device according to  claim 5 , characterized in that the reference object ( 35 ;  35   a ;  35   b ) produces a damping of x-radiation which is greater at one location and smaller at one location than the damping produced by the pharmaceutical product ( 1 ). 
     
     
         8 . The device according to  claim 5 , characterized in that a surface of the reference object ( 35 ;  35   a ;  35   b ) is perpendicularly aligned to the radiation cone ( 27 ;  36 ,  37 ). 
     
     
         9 . A method for determining the weight of pharmaceutical products ( 1 ) by means of a device ( 10 ;  10   a ) according to  claim 1 , characterized in that the pharmaceutical product ( 1 ) and the reference object ( 35 ;  35   a ;  35   b ) are simultaneously radiographed by means of the X-ray source ( 28 ), in that an image of an irradiated pharmaceutical product ( 1 ) and of the reference object ( 35 ;  35   a ;  35   b ) are supplied to the evaluation device ( 32 ) by at least one image recording sensor element ( 30 ;  30   a ), in that the evaluation device ( 32 ) examines the irradiated pharmaceutical product ( 1 ) pixel by pixel for a gray scale value thereof and associates the same gray scale value on the reference object ( 35 ;  35   a ;  35   b ) and thereby a thickness of said reference object ( 35 ;  35   a ;  35   b ) with the gray scale value of the respective pixel, in that an average thickness is subsequently determined across all of the pixels, in that thereafter in knowledge of a number and surface area of the pixels, a virtual volume of the pharmaceutical product ( 1 ) is calculated; and in that in a final step, the virtual volume of said pharmaceutical product ( 1 ) is multiplied by the thickness of said pharmaceutical product ( 1 ) to determine the weight of said pharmaceutical product ( 1 ). 
     
     
         10 . The method according to  claim 9 , characterized in that in the case of consecutive images, the gray scale values of the reference object ( 35 ;  35   a ;  35   b ) are compared with each other and in the event of a deviation, a correction factor is applied to the current gray scale value.