Title of Invention	A METHOD AND DEVICE FOR MEASURING THREE PARAMETERS REGARDING PHARMACEUTICAL POWDERS FLUIDITY IN ONE OPERATION
Abstract	The packing arrangement of a powder/granules bed depends on the nature and extent of friction among the particles/granules. The bulk volume of a powder depends on packing arrangement of particles, and the packing arrangement in turn depends on inter-particular or inter-granular friction or in other words, bulk volume VB of a given powder depends on the inter-particular friction. The nature and extent of friction among particles/granules is quantified by coefficient of friction (~) viz. tangent of the angle of repose (8) Therefore VB a VB a tan 8 VB = Ktan 8 for a given conical heap of a powder / granules. Tan 8 = H/R, where H is the height of the cone and R is the radius of the cone. and VB = 1/3 h R2H The nature of relationship between the coefficient of friction and the bulk volume of the conical powder heap whose base is assumed to be constant (R) is constant while H varies. Ref. Table 1. Where in the radius of conical heap is fixed as 2 cm.

Title of Invention

A METHOD AND DEVICE FOR MEASURING THREE PARAMETERS REGARDING PHARMACEUTICAL POWDERS FLUIDITY IN ONE OPERATION

Abstract

The packing arrangement of a powder/granules bed depends on the nature and extent of friction among the particles/granules. The bulk volume of a powder depends on packing arrangement of particles, and the packing arrangement in turn depends on inter-particular or inter-granular friction or in other words, bulk volume VB of a given powder depends on the inter-particular friction. The nature and extent of friction among particles/granules is quantified by coefficient of friction (~) viz. tangent of the angle of repose (8) Therefore VB a VB a tan 8 VB = Ktan 8 for a given conical heap of a powder / granules. Tan 8 = H/R, where H is the height of the cone and R is the radius of the cone. and VB = 1/3 h R2H The nature of relationship between the coefficient of friction and the bulk volume of the conical powder heap whose base is assumed to be constant (R) is constant while H varies. Ref. Table 1. Where in the radius of conical heap is fixed as 2 cm.

Full Text	Fluidity of powders plays a vital role in oral shod dosage foams via tablets, and capsules apart from other occasions like sterile powders etc. Generally fluidity is defamed by angle of rosés for any powder or powder mix. There are four methods both static and dynamic categories put together. 1. Fixed height cone 2. Fixed base cone 3. Tilting table 4. Rotating cylinder Bui none of these methods can give the following measurements through a single operation. 1. Coefficient of friction of a given hopper mix 2. Fluidity of the hopper mix/bulk powder 3. Bulk volume of hopper mix Hence a simple apparatus is thought of) designed, fabricated and engineered in order to measure all the three parameters in a single operation. This is supposed to be an integral apparatus named tentatively as "Vimsaurogaph". Using Vimsaurograph the flow properly of a given drug powder/granules can be understood by the deuce visual observation of color zone on the dial as read by the needle. The angle of repose can be directly read from the prepared table bateau coefficient of friction to corresponding angle of repose (9) for different heights of the powder cones being formed on the base. The reckon tables together with the day reading of the instrument would enable the operator to make quick assumption and adjustments during the manufacturing process of dosage forms like tablets, capsules. Thus the apparatus "Vimsaurograph" is a simple device based on fixed cone base method directly converting the height of the powder cone into the coefficient of friction, apparent bulk volume and fluidity m a squiggle operation, which can be integrated to the desired prototype dimensions. Field of Invention This invention relates to a measuring instilment and the process for obtaining alb the three parameters relating to Pharmaceutical powders, fluidity in one operation. Prior Art: Fluidity of powders is highly essential in both tablet and capsule dosage forms, ^art from the other occasions in pharmaceutical industries. Hitherto, fluidity is defined indirectly by angle of repose for a powder. The angle of repose can be measured by four (static or dynamic) methods, which are in current practice. They are (1) Fixed height cone (2) Fixed base cone (3) Tilting table (4) Rotating cylinder. But none of them are either satisfectory or accurate. ISI (Indian Standards histitute) does not contain a monograph, or a me^od for determining fluidity of bulk powders throu^ angle of repose. ASTM (American Standards of Tests and Materials) has given a method of flow rate of metal powder using flow meter fiamel, but not for pharmaceutical powders. None of the above methods can give the following measurements through a single operation. Viz; 1. To find the coefficient of friction of a given hopper mix/bulk powder. 2. To indicate the fluidity of the hopper mix1)ulk powder. 3. To find die poured/apparent bulk volume of hopper maul powder. In order to measure the above three parameters throe a smugly operation, a simple device is designed, engineered and fabricated which is an integral apparatus. The desk of the apparatus is based on the principle, "Fixed base cone method". This device is developed by modification of fixed base cone métier, which can directly convert the height of powder cone into coefficient of friction of poured/apparent bulk volume m simple operation. Summary of Invention The primary objective of this invention is to design a device for measuring three parameters referred above 1,2,3 regarding phannaceutical powders, which is unique. The second objective of this mention is to design a unique device, in the above said parameters Hire the conversion of dial reading directly. A device for measuring three parameters(. Co.-efficient of friction of a given hopper mix-bulk powder 2. Fluidity of the hopper mix/bulk powder . 3. Poured/apparent bulk volume of hopper mix/bulk powder) regarding pharmaceuticEd powders in one operation, which comprises a main frame, a fixed base, a rack and pinion arrangement and a dial, the where in the device work in tandem and can measure :^1 the three aforesaid parameters regarding pharmaceutical powders in « eir^^u - The third objective of the invention ■» lu uesign a device, which is Sturdy, efficient, economical and ease in operational feasibility. Further objectives of the invention will be apparent in the ensuing description. Now the invention will be described with reference to drawings wherein. Fig I Shows elevation of the side views and front view of the device according to invention. Fig 2, Shows 3 Dimensional, side view of the device according to invention. Fig 3. Shows another embodiment of the invention in side view. Fig 4. Shows elevation and plan of the device. Fig 5. Shows the different views of the Rack and Pinion-Fig 6. Shows the elevation of the front dial used in the device. Fig 7. Shows relationship between (i)Coefficient of frictioti and poured/app^ent bulk volume, {ii)Height and apparent bulk volume, and (iii)Height and coefficient of friction, with respect to the constant base of the device. The packing arrangement of a powder/granule bed largely depends on the nature and extent of friction among the particles / granules. The bulk volume of a powder depends on packing arrangement of panicles; and the packing arrangement in turn depends on inter particular or inter-granular friction, in other words, bulk volume (VB) of a given powder depends on the inter particular friction (jt). The nature and extent of friction among particles / granules is quantified by coefficient of fiiction (\t). Viz. Tangent of the angle of repose (8). Therefore, VB a M i.e. VB a tan 9 VB=Ktane Wherein VB ~ is Poured /apparent bulk volume and 6 - angle of repose For a given conical heap of a powder/granules, Tane = H/R, Where H is the height of the cone and R is the radius of the cone. AndVB = inR^H Tlie nature of rdationship between the coefficient of fiiction and the bulk volume of a conical powder heap whose base is assumed to be constant (R is constant while H varies) is shown from the values in table 1 wiiere the radius of conical heap is assumed to be 2 cm. Table I. Coefficient of friction and poured/apparent bulk volume with vai>"ing Height of conical heaps and with a constant b^e rjuJius 2 cm. Height of Conical heap, cm Coefficient of friction, ji Poured/apparent built volume iVj)_cc 0 0 0 0.5 0.25 2,1 I.O 0.50 4,2 1.5 0.75 6.3 2,0 1.00 8.4 2.5 1.25 10.5 3.0 1.50 12.6 3.5 1.75 14.7 4.0 2.00 16.8 As mentioned earlier, the angle of repose can be measured by either fixed hei^t cone method or fixed radius method. In the design of the present apparatus the principle of fixed radius method is adopted, where R, the radius of the conical heap of the powder, being constant. In this case, R being constant, tan O a H, die height of the conical heap of the powder. Tan e = Ki H Where Kz is the proportionality constant equal to VR, which depends on the radius of the fixed base adopted. Also VB a H, the height of the conical heap of the powder Where K3 is the proportionality constant equal to and depends on the radius of the fixed base adopted. The relationships between the heights of the diff^ent conical heaps with constant base of radius 2 cm and the corresponding poured/apparenr bulk volumes and coefficients of friction and shown in fig I. The device for measuring three parameters regarding phamiaceutical powders is shown in the fig 1. The main constituents of the device are as follows: ♦ Main frame of the apparatus ♦ A fixed base ♦ A Rack & Pinion arrangement ♦ A dial, in the device is arranged in such a way that the main constituents work in turn thereby the device can ineasure three parameters regarding pharmaceuticai powders in a single operation. Main features of the device : The main frame consists of a rectangular platform (A) with a stand fixed at one end to hold a movable hood (B) (as shown in the fig.2). One end of the movable hand (B) is attached to the stand with the help of hinge and the other end is fit with a set of Rack and Pinion and a dial. Rack & Pinion arrangement is denoted by (C). Fixed Base (Notion D): Based on the calculations mentioned in table I, in the design of the device fixed base of 2 cm radius is arranged on platform A as shown in Fig. 2. Rack and Pinion Set In order to measure the heights of conical heaps of dififerent powders / granules formed on the fixed base for deteraiination of coefficient of fiiction and poured/apparent bulk volume (VB), a vertically movable rack and pinion set with the tip of the rack exactly in alignment with the center of the fixed base E was arranged. A movable needle was attached to the knob of the pinion to record the movements of the rack on the dial This set is attached to the movable hood (B) of the main frame of tlie apparatus. The rack moves up through a maximum distance of 4 cm irom the base. The dial The variations in the heights of different cones, when formed on the base with different powders can be measured vrith the help of the Rack and Pinion set, A dial of 15cm diameter is designed and calibrated to convert these variations in the heists of the cones directly into coefficient of friction (ja) and poured/apparent bulk volume (VB) as per the calculations shown in table i. Two circles are drawn on the dial. The outer circle is divided into equal parts to measure the coefficient of the friction from 0 to 2. The irmer circle is divided into equal parts to measure the bulk volume from 0 to 16.8 cubic centimeters. Besides the above, the fluidity ranges based on the angle of repose values table 2 are marked on tbe dial with different colours as shown in the fig.3. The dial is fit to the movable hood (B) over the rack and pinion set such that the needle, on the knob of the pinion, moves over the dial to read the variations in the heights of the cone in terms of the coefficients of fiiction on the outer circle and poured/apparent bulk volume on the inner circle as well as the fluidity ranges on tiie outer circle by colour indicators. The design is so made that the position of the needle on the dial can be adjusted without disturbing the position of the Rack during the course of experimentation. Table 2 Angle of repose CoefTicient of Type of flow Zone (Degrees) friction 25-30 0.47-0.58 Good Yellow 30-40 0.58-0.84 j Acceptable Orange >40 >0.84 1 Very poor Red Method of operation The method of determination of the coefficient of fticrion (fi), poured/apparent bulk volume (VB) and the fluidity range of a given powder / granules is described in a step wise manner as follows. Step I: Ensure the normal position of the movable hood (B) and then check the level of the base using an external level indicator. Step 2 ; Once the base is leveled, the movable hood (B) (fitted with dial over the Rack & Pinion) is lifted up, to rest on the back of the hinge and a transparent PVC sheet is used to wrap the base to form a hoUow cylinder over the base. Step 3 : Pour the powder / granules, whose coefficient of fiiction (fx). poured/apparent bulk volume (VB) and fluidity range are to be measured, into the fixed base to fill the hollow cylindrical space formed by the wrapper. Step 4 : Remove the wrapper slowly without disturbing the powder bed so that the excess powder / granules slide down the base to fonn a cone. Step 5 : Once the cone is formed on the base (E), bring back the movable hood (B) to the normal position slowly, while adjusting the position of the Rack such that its tip just touches the apex of the cone. Step 6 : Adjust the dial reading to "Zero" without disturbing the position of the Rack. Step 7 : Remove the powder / granules torn the base carefiilly to weight for the determination of untapped bulk densify, from the bulk volume (VB) to be obtained fi"Om the dial reading. Step 8 : Lower down the rack till its tip touches the center of the base. Step 9 : Note down the dial reading to give VB and fluidity range of the powder/granules. Step 10 : Repeat the experiment for 3-4 times to get the concurrent readings. Comparative values of the coefficients of fiiction & angle of repose of different pharmaceutical granules of Light Magiwsium Carbonate (LMC), Aspirin (ASPN) and Paracetamol (PCML), determined by fixed height funnel method and by this device are given in table 3, also the bulk volume determined by measuring cylinder method and by this device. Using this device the flow property of a given drug powder/granules can be understood by the direct visual observation of colour zone on the dial, read by the needle. However, in order to know the angle of repose, a conversion table (table 4) from coefficient of friction (\i) to corresponding angle of repose (0) for different heights of the powder cones being formed on the base is prepared as a ready reckoner. The reckoner tables 2 and 4 together with the dial reading would enable the operator to do quick assumptions / adjustments during the manufacturing process of dosage forms like tablets, capsules. We claim : 1. A device for measuring three parameters(. Co.-efficient of friction of a given hopper mix-bulk powder 2. Fluidity of the hopper mix/bulk powder . 3. Poured/apparent bulk volume of hopper mix/bulk powder) regarding pharmaceutical powders in one operation, w4iich comprises a main frame, a fixed base, a rack and pinion arrangement and a dial, the where in the device work in tandem and can measure all the three aforesaid parameters regarding pharmaceutical powders in a single operation. 2. A device for measuring all the three parameters regarding pharmaceutical powders as in claim 1 and a ready reckoned for the three parameter as in claim I in a single operation, wherein the main frame consists of the rectangular platform with a stand fixed at one end to hold a movable hood, one end of the movable hard is attached to the stand with hinge and the other end is fitted with a set of rack and pinion and a dial. 3. A device as in claim 1 wherein rack and pinion set is such that in order to measure the heights of conical heaps of different powders/granules formed on the fixed base for determination of coefficient of friction and poured/apparent bulk volume, a vertically movable rack and pinion set with the tip of the rack exactly in alignment with the center of the fixed base is arranged, a movable needle was attached to the knob of the pinion to record the movements of the rack on the dial, this set is attached to the movable hood of the main frame of the apparatus. 4. A device for measuring three parameters for a given pharmaceutical powder as in Claim wherein the dial which is calibrated to convert the variations in the heights of the cones, directly into coefficient of fiction from 0-2. 5. A device for measuring three parameters regarding pharmaceutical powders as described in complete specification and as illustrated through drawings. Dated this 24* day SeptemberI998. (M.Vimala Devi) ABSTRACT The packing arrangement of a powder/granules bed depends on the nature and extent of friction among the particles/granules. The bulk volume of a powder depends on packing arrangement of particles, and the packing arrangement in turn depends on inter-particular or inter-granular friction or in other words, bulk volume VB of a given powder depends on the inter-particular friction. The nature and extent of friction among particles/granules is quantified by coefficient of friction (fi) VIZ, tangent of the angle of repose (8) Tan H/R, where H is the height of the cone and R is the radius of the cone, and VB = 1/3 H R^H The nature of relationship between the coefficient of friction and the bulk volume of the conical powder heap whose base is assumed to be constant (R) is constant while H varies. Ref Table 1. Where in the radius of conical heap is fixed as 2 cm.

Full Text

Fluidity of powders plays a vital role in oral shod dosage foams via tablets, and capsules apart from other occasions like sterile powders etc. Generally fluidity is defamed by angle of rosés for any powder or powder mix. There are four methods both static and dynamic categories put together.
1. Fixed height cone
2. Fixed base cone
3. Tilting table
4. Rotating cylinder
Bui none of these methods can give the following measurements through a single operation.
1. Coefficient of friction of a given hopper mix
2. Fluidity of the hopper mix/bulk powder
3. Bulk volume of hopper mix
Hence a simple apparatus is thought of) designed, fabricated and engineered in order to measure all the three parameters in a single operation. This is supposed to be an integral apparatus named tentatively as "Vimsaurogaph".
Using Vimsaurograph the flow properly of a given drug powder/granules can be understood by the deuce visual observation of color zone on the dial as read by the needle. The angle of repose can be directly read from the prepared table bateau coefficient of friction to corresponding angle of repose (9) for different heights of the powder cones being formed on the base.
The reckon tables together with the day reading of the instrument would enable the operator to make quick assumption and adjustments during the manufacturing process of dosage forms like tablets, capsules. Thus the apparatus "Vimsaurograph" is a simple device based on fixed cone base method directly converting the height of the powder cone into the coefficient of friction, apparent bulk volume and fluidity m a squiggle operation, which can be integrated to the desired prototype dimensions.

Field of Invention
This invention relates to a measuring instilment and the process for obtaining alb the three parameters relating to Pharmaceutical powders, fluidity in one operation.
Prior Art:
Fluidity of powders is highly essential in both tablet and capsule dosage forms, ^art from the other occasions in pharmaceutical industries. Hitherto, fluidity is defined indirectly by angle of repose for a powder. The angle of repose can be measured by four (static or dynamic) methods, which are in current practice. They are (1) Fixed height cone (2) Fixed base cone (3) Tilting table (4) Rotating cylinder. But none of them are either satisfectory or accurate. ISI (Indian Standards histitute) does not contain a monograph, or a me^od for determining fluidity of bulk powders throu^ angle of repose. ASTM (American Standards of Tests and Materials) has given a method of flow rate of metal powder using flow meter fiamel, but not for pharmaceutical powders.
None of the above methods can give the following measurements through a single operation. Viz;
1. To find the coefficient of friction of a given hopper mix/bulk powder.
2. To indicate the fluidity of the hopper mix1)ulk powder.
3. To find die poured/apparent bulk volume of hopper maul powder.
In order to measure the above three parameters throe a smugly operation, a simple device is designed, engineered and fabricated which is an integral apparatus. The desk of the apparatus is based on the principle, "Fixed base cone method". This device is developed by modification of fixed base cone métier, which can directly convert the height of powder cone into coefficient of friction of poured/apparent bulk volume m simple operation.
Summary of Invention
The primary objective of this invention is to design a device for measuring three parameters referred above 1,2,3 regarding phannaceutical powders, which is unique.
The second objective of this mention is to design a unique device, in the above said parameters Hire the conversion of dial reading directly.

A device for measuring three parameters(. Co.-efficient of friction of a given hopper
mix-bulk powder 2. Fluidity of the hopper mix/bulk powder . 3. Poured/apparent bulk
volume of hopper mix/bulk powder) regarding pharmaceuticEd powders in one operation,
which comprises a main frame, a fixed base, a rack and pinion arrangement and a dial,
the where in the device work in tandem and can measure :^1 the three aforesaid
parameters regarding pharmaceutical powders in « eir^^u -

The third objective of the invention ■» lu uesign a device, which is Sturdy, efficient, economical and ease in operational feasibility.
Further objectives of the invention will be apparent in the ensuing description.
Now the invention will be described with reference to drawings wherein.
Fig I Shows elevation of the side views and front view of the device according to invention. Fig 2, Shows 3 Dimensional, side view of the device according to invention. Fig 3. Shows another embodiment of the invention in side view. Fig 4. Shows elevation and plan of the device. Fig 5. Shows the different views of the Rack and Pinion-Fig 6. Shows the elevation of the front dial used in the device. Fig 7. Shows relationship between (i)Coefficient of frictioti and poured/app^ent bulk
volume, {ii)Height and apparent bulk volume, and (iii)Height and coefficient of
friction, with respect to the constant base of the device.
The packing arrangement of a powder/granule bed largely depends on the nature and extent of friction among the particles / granules. The bulk volume of a powder depends on packing arrangement of panicles; and the packing arrangement in turn depends on inter particular or inter-granular friction, in other words, bulk volume (VB) of a given powder depends on the inter particular friction (jt).
The nature and extent of friction among particles / granules is quantified by coefficient of fiiction (\t). Viz. Tangent of the angle of repose (8).
Therefore, VB a M
i.e. VB a tan 9 VB=Ktane Wherein VB ~ is Poured /apparent bulk volume and 6 - angle of repose For a given conical heap of a powder/granules, Tane = H/R,
Where H is the height of the cone and R is the radius of the cone. AndVB = inR^H

Tlie nature of rdationship between the coefficient of fiiction and the bulk volume of a conical powder heap whose base is assumed to be constant (R is constant while H varies) is shown from the values in table 1 wiiere the radius of conical heap is assumed to be 2 cm.
Table I. Coefficient of friction and poured/apparent bulk volume with vai>"ing Height of conical heaps and with a constant b^e rjuJius 2 cm.

Height of Conical heap, cm Coefficient of friction, ji Poured/apparent built volume
iVj)_cc
0 0 0
0.5 0.25 2,1
I.O 0.50 4,2
1.5 0.75 6.3
2,0 1.00 8.4
2.5 1.25 10.5
3.0 1.50 12.6
3.5 1.75 14.7
4.0 2.00 16.8
As mentioned earlier, the angle of repose can be measured by either fixed hei^t cone method or fixed radius method.
In the design of the present apparatus the principle of fixed radius method is adopted, where R, the radius of the conical heap of the powder, being constant.
In this case, R being constant, tan O a H, die height of the conical heap of the powder.
Tan e = Ki H
Where Kz is the proportionality constant equal to VR, which depends on the radius of the fixed base adopted.
Also VB a H, the height of the conical heap of the powder
Where K3 is the proportionality constant equal to and depends on the radius of the fixed base adopted.

The relationships between the heights of the diff^ent conical heaps with constant base of radius 2 cm and the corresponding poured/apparenr bulk volumes and coefficients of friction and shown in fig I.
The device for measuring three parameters regarding phamiaceutical powders is shown in the fig 1. The main constituents of the device are as follows:
♦ Main frame of the apparatus
♦ A fixed base
♦ A Rack & Pinion arrangement
♦ A dial, in the device is arranged in such a way that the main constituents work in turn thereby the device can ineasure three parameters regarding pharmaceuticai powders in a single operation.
Main features of the device :
The main frame consists of a rectangular platform (A) with a stand fixed at one end to hold a movable hood (B) (as shown in the fig.2). One end of the movable hand (B) is attached to the stand with the help of hinge and the other end is fit with a set of Rack and Pinion and a dial. Rack & Pinion arrangement is denoted by (C).
Fixed Base (Notion D):
Based on the calculations mentioned in table I, in the design of the device fixed base of 2 cm radius is arranged on platform A as shown in Fig. 2.
Rack and Pinion Set
In order to measure the heights of conical heaps of dififerent powders / granules formed on the fixed base for deteraiination of coefficient of fiiction and poured/apparent bulk volume (VB), a vertically movable rack and pinion set with the tip of the rack exactly in alignment with the center of the fixed base E was arranged. A movable needle was attached to the knob of the pinion to record the movements of the rack on the dial This set is attached to the movable hood (B) of the main frame of tlie apparatus. The rack moves up through a maximum distance of 4 cm irom the base.

The dial
The variations in the heights of different cones, when formed on the base with different powders can be measured vrith the help of the Rack and Pinion set, A dial of 15cm diameter is designed and calibrated to convert these variations in the heists of the cones directly into coefficient of friction (ja) and poured/apparent bulk volume (VB) as per the calculations shown in table i. Two circles are drawn on the dial. The outer circle is divided into equal parts to measure the coefficient of the friction from 0 to 2. The irmer circle is divided into equal parts to measure the bulk volume from 0 to 16.8 cubic centimeters. Besides the above, the fluidity ranges based on the angle of repose values table 2 are marked on tbe dial with different colours as shown in the fig.3. The dial is fit to the movable hood (B) over the rack and pinion set such that the needle, on the knob of the pinion, moves over the dial to read the variations in the heights of the cone in terms of the coefficients of fiiction on the outer circle and poured/apparent bulk volume on the inner circle as well as the fluidity ranges on tiie outer circle by colour indicators. The design is so made that the position of the needle on the dial can be adjusted without disturbing the position of the Rack during the course of experimentation.

Table 2
Angle of repose CoefTicient of Type of flow Zone
(Degrees) friction
25-30 0.47-0.58 Good Yellow
30-40 0.58-0.84 j Acceptable Orange
>40 >0.84 1 Very poor Red
Method of operation
The method of determination of the coefficient of fticrion (fi), poured/apparent bulk volume (VB) and the fluidity range of a given powder / granules is described in a step wise manner as follows.
Step I: Ensure the normal position of the movable hood (B) and then check the level of the base using an external level indicator.

Step 2 ; Once the base is leveled, the movable hood (B) (fitted with dial over the Rack & Pinion) is lifted up, to rest on the back of the hinge and a transparent PVC sheet is used to wrap the base to form a hoUow cylinder over the base.
Step 3 : Pour the powder / granules, whose coefficient of fiiction (fx). poured/apparent bulk volume (VB) and fluidity range are to be measured, into the fixed base to fill the hollow cylindrical space formed by the wrapper.
Step 4 : Remove the wrapper slowly without disturbing the powder bed so that the excess powder / granules slide down the base to fonn a cone.
Step 5 : Once the cone is formed on the base (E), bring back the movable hood (B) to the normal position slowly, while adjusting the position of the Rack such that its tip just touches the apex of the cone.
Step 6 : Adjust the dial reading to "Zero" without disturbing the position of the Rack.
Step 7 : Remove the powder / granules torn the base carefiilly to weight for the determination of untapped bulk densify, from the bulk volume (VB) to be obtained fi"Om the dial reading.
Step 8 : Lower down the rack till its tip touches the center of the base.
Step 9 : Note down the dial reading to give VB and fluidity range of the powder/granules.
Step 10 : Repeat the experiment for 3-4 times to get the concurrent readings.
Comparative values of the coefficients of fiiction & angle of repose of different pharmaceutical granules of Light Magiwsium Carbonate (LMC), Aspirin (ASPN) and Paracetamol (PCML), determined by fixed height funnel method and by this device are given in table 3, also the bulk volume determined by measuring cylinder method and by this device.

Using this device the flow property of a given drug powder/granules can be understood by the direct visual observation of colour zone on the dial, read by the needle. However, in order to know the angle of repose, a conversion table (table 4) from coefficient of friction (\i) to corresponding angle of repose (0) for different heights of the powder cones being formed on the base is prepared as a ready reckoner.
The reckoner tables 2 and 4 together with the dial reading would enable the operator to do quick assumptions / adjustments during the manufacturing process of dosage forms like tablets, capsules.

We claim :
1. A device for measuring three parameters(. Co.-efficient of friction of a given hopper mix-bulk powder 2. Fluidity of the hopper mix/bulk powder . 3. Poured/apparent bulk volume of hopper mix/bulk powder) regarding pharmaceutical powders in one operation, w4iich comprises a main frame, a fixed base, a rack and pinion arrangement and a dial, the where in the device work in tandem and can measure all the three aforesaid parameters regarding pharmaceutical powders in a single operation.
2. A device for measuring all the three parameters regarding pharmaceutical powders as in claim 1 and a ready reckoned for the three parameter as in claim I in a single operation, wherein the main frame consists of the rectangular platform with a stand fixed at one end to hold a movable hood, one end of the movable hard is attached to the stand with hinge and the other end is fitted with a set of rack and pinion and a dial.
3. A device as in claim 1 wherein rack and pinion set is such that in order to measure the heights of conical heaps of different powders/granules formed on the fixed base for determination of coefficient of friction and poured/apparent bulk volume, a vertically movable rack and pinion set with the tip of the rack exactly in alignment with the center of the fixed base is arranged, a movable needle was attached to the knob of the pinion to record the movements of the rack on the dial, this set is attached to the movable hood of the main frame of the apparatus.
4. A device for measuring three parameters for a given pharmaceutical powder as in Claim wherein the dial which is calibrated to convert the variations in the heights of the cones, directly into coefficient of fiction from 0-2.
5. A device for measuring three parameters regarding pharmaceutical powders as described in complete specification and as illustrated through drawings.
Dated this 24* day SeptemberI998. (M.Vimala Devi)

ABSTRACT
The packing arrangement of a powder/granules bed depends on the nature and extent of friction among the particles/granules. The bulk volume of a powder depends on packing arrangement of particles, and the packing arrangement in turn depends on inter-particular or inter-granular friction or in other words, bulk volume VB of a given powder depends on the inter-particular friction.
The nature and extent of friction among particles/granules is quantified by coefficient of friction (fi) VIZ, tangent of the angle of repose (8)

Tan H/R, where H is the height of the cone and R is the radius of the cone, and VB = 1/3 H R^H
The nature of relationship between the coefficient of friction and the bulk volume of the conical powder heap whose base is assumed to be constant (R) is constant while H varies. Ref Table 1.
Where in the radius of conical heap is fixed as 2 cm.

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Patent Number

217201

Indian Patent Application Number

2147/MAS/1998

PG Journal Number

21/2008

Publication Date

23-May-2008

Grant Date

26-Mar-2008

Date of Filing

24-Sep-1998

Name of Patentee

PROF. M. VIMALA DEVI

Applicant Address

DEPT. OF. PHARMACEUTICAL SCIENCES, ANDHRA UNIVERSITY, VISAKHAPATNAM - 530 003,

Inventors:

#	Inventor's Name	Inventor's Address
1	M. VIMALA DEVI	DEPT. OF. PHARMACEUTICAL SCIENCES, ANDHRA UNIVERSITY, VISAKHAPATNAM - 530 003,
2	DR. S. SRINIVASA RAO	DEPT. OF. PHARMACEUTICAL SCIENCES, ANDHRA UNIVERSITY, VISAKHAPATNAM - 530 003,

PCT International Classification Number

G01N 011/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA