AU427690B2 - Process for production spherical pellets - Google Patents

Description

30,04 8/71 This invention relates to a process for producing

pellets, and more particularly to a process for producing

spherical pellets of uniform sizes which comprises adding

a binder liquid to granules consisting of at least one of colloidal synthetic silicon dioxide, synthetic silicates of aluminum and magnesium, aluminum hydroxide gel, aluminum hydroxide magnesium hydroxide gel, aluminum hydroxide aluminum carbonate gel and synthetic magnesium aluminum hydroxide carbonate thereby to prepare wet nucleus granules, and spraying the wet nucleus granules in a discretely flowing state onto powders thereby to produce spherical pellets. Pellets have various advantages when used, and therefore the pellets have been widely utilized in every industrial fields. For example, pelletized drug can be more readily administrated orally than the powdery drug, as a medicament. Further, the drug can be more readily stabilized and more simply handled when the drug is in a pellet form. Furthermore, by applying a suitable coating to the pelletized drug when necessary, dissolution of the drug can be controlled or retarded, whereby a medically effective time can be pro- longed, or by applying an enteric coating to the pelletized drug, decomposition of the drug within the digestive tract by an action of an acidity of gastric juice or enzyme can be prevented. Still furthermore, by applying a moisture- prodf coating to the pelletized drug, a decomposition of the drug due to the absorption of moisture can be A 4276 preveted 1 30104871 preentdor'd disagreeable taste due to the nature of the drug can be eliminated. The pelletized drug- has so many advantages as mentioned above as a medicament that a large number of studies have been so far made on processes for producig pellets. Among others, a process for producing spherical pellets having excellent properties has been studied. in every industrial field. For example, there have been proposed a process for making spherical pellets by rolling wet granules with plasticity formed accord- ing to an extrusion-type wet granulating method, together with spheres in a pan (Japanese Patent Publication No. 27722/68); a process fLor making small spheres by rolling a drug of almost sj~herical crystals in a coating pan, wetting the drug with an adhesive solution and placing the, drug thereon (Japanese Patent Publicati on No. 4406/69); a process Zor making wet granules prepared by an extrusion-type wet granulator into spherical ones on a disc having a friction sur- face and revolving at a high speed (Japanese Patent Publication No. 563/66); a process for prod-,7cing spherical pellets by melting a drug together with a low melting point material, spraying the molten mixture from a suitable nozzle and conagealing the sprayed mixture in the cool air (Japanese Patent- Publication No. 17600/60); a process for obtaining spherical pellets by rolling powders -while. adding 'water droplets thereto dropwise or spraywise in one of various rolling-type granulators, or the like. However, these prior art processes have47 0

30,04,81/71 specific advaAtages, but in said processes for making wet granules into spherical pellets (Japanese Patent Publication Nos. 27722/68 and 563/66) it is an essential requirement for making the wet granules into spherical pellets, that the wet granules have a plasticity. To make the vet pellets plastic, it is

necessary to add a suitable plastic material thereto.' or adjust a water content of the wet granules to a narrow range capable of making the granules into spherical ones. In these prior art processes, there is an inevitable difficulty such as a restriction of a prescription or proper control of moisture for making the wet granules plastic, depending upon the properties and prescription of the powders ured. Further, in the process for making small spheres by spraying an adhesive solution onto crystalline drug to make wet the drug and placing the drug thereon (Japanese Patent Publication No. 4406/69) or process for obtaining spherical pellets by spraying liquid droplets on rolling powders in a rolling granulator, or the like, the crystalline drug wetted with water or the adhesive solution, etc., which serves as nuclei, or the powders to be pelletized, are aggregated with each other, and the secondary or tertiary aggregates 'si-e thereby formed. Therefore, it is dif- ficult to obtain spherical pellets having the desired- uniform sizes In high yield. In said prior art pro-.. cesse6, a highly complicated art and skill are necessary for spraying water or a binder solution such as an adhesive solution, etc. to make uniform the sizes of the spherical pellets. Furthermore, in

30,04 8/71 the process fbr making spherical pellets by melting a drug together with a low nkelting point material, spraying the mixtur'e through a suitable nozzle and congealing .the sprayed mixture in cool air (Japanese Patent Publication N~o. 17600/60), a special apparatus is necessary for making granules, and the materials to be pelletized by said process are limited. Therefore, said prior art process cannot be applied to the granulation or pcslletization of the drug in a wide range. As described above, there have been no processes which can satisfy the ready production of spherical pellets suitable for the medical use. The present inventors have made various studies on a process for producing spherical pellets having uniform sizes, which are suitable for medical use, and further on a process for obtaining pellets having uniform sizes in other shapes than the spherical* shape, and, as a result, have accomplished the present invention. That is to say, an object of the present invention is to provide a process for producing pellets having uniform shapes and sizes readily in high yield by adding a binder liquid to granules consisting of at least one of colloidal synthetic silicon dioxide, synthetic silicate of aluminum and magnesium, aluminum hydroxide gel, aluminum hydroxide -magnesium hydroxide gel, aluminum hydroxide -aluminum carbonate gel, and synthetic magnesium aluminum hydroxide carbonate thereby to form vet nucleus granules and spraying the thus obtained wet nucleus granules in a discretely K. 5 4276.90

3 0,04 8 7 flowing state onto powders thereby to deposit the powders

onto the granules layer by layer and make the granules grow.

According to the present invention, not only the spherical pellets but also pellets in other shapes can be

readily obtained.

The intensive study of application of the present

process to the medical field has revealed that said substances

are most suitable for the present process.

That is to say, as a result of the studies on the

properties necessary for the nucleus granules when pellets applicable to medical use are prepared, the present inventors

have found that it is necessary that the substances must

keep their shapes when the substances have a suitable water

content, and must have an ability to readily release a portion of water contained in the substance during the rolling, pick up the powder and grow, and further that the substances must

have a good flowability and suitable and uniform sizes.

Further, as a result of the studies on the production in an industrial scale, the present inventors have found that the granules made from said substances can meet these properties,

and when a binder liquid, such as water, alcohol, etc. is added to the granules, and the granules containing the binder liquid are used as the wet nucleus granules, pellets having uniform sizes can be readily produced in high yield.

The substances, which can be used as the nucleus

granules, can contain a large amount of water. That is, the present substances can contain, in a. powdery state, water in an amount almost equal to or at most a few times the weight

of the substances. The present substances can be readily

6 4276

3004 8/71 granulated and the resulting granules can keep a proper hardness, even dried, and cannot readily lose their original shapes even if a binder liquid is added thereto. The granules of the present substances have a good flowability enough to be sprinkled, even if the granules contain the binder liquid in an amount almost equal to the weight of the present sub- stances. According to the present process, at least one of colloidal synthetic silicon dioxide, for example, white carbon; synthetic silicates of aluminum and magnesium, for example, synthetic aluminum silicate, synthetic magnesium silicate, metamagnesium aluminosilicate, dimagnesium alumino- silicate; aluminum hydroxide gel; aluminum hydroxide mag- nesium hydroxide gel; aluminum hydroxide aluminum carbonate and synthetic magnesium aluminum hydroxide carbonate is granulated to nucleus granules by the ordinary extrusion- type granulating method, grinding-type granulating method or the spray granulating method for spraying undried slurry after the synthesis. Though the shapes of the nucleus granules are not particularly limited, the granules obtained by the spray-drying method are most suitable for the present process, particularly for the process for obtaining spherical pellets.

-30,048/71 According to the present invention, the

shape of the final product, pellets, depends upon the

shape of nucleus granules. For example, when spherical

pellets are desired, spherical or nearly spherical

nucleus granules or cylindrical or square rod nucleus

granules having a ratio of shorter dimension to longer

dimension of 1 1.5 or less are selected.

As a method for adding a binder liquid to

the nucleus granules of the present invention, it is

desirable to add.the binder liquid to the granules

without deforming the shapes of the nucleus granules.

For example, there are .available a method for spraying

the liquid onto the nucleus granules while rolling the

nucleus granules in a coating pan; a method which

comprises depositing a predetermined amount of the nucleus granules in a suitable vessel, spraying a

predetermined amount of a binder liquid onto the

granules, leaving the sprayed granules standing for

a substantial period of time, then screening the

granules through a wire sieve having opening sizes

about twice as large as the sizes of the nucleus

granules and blending the granules in a V-shape

blender for a short period of time,etc. According

to the these methods, the wet nucleus granules

capable of being readily sprinkled can be obtained.

As the binder liquid to be added to the

nucleus granules of the present invention, water is

principally used, but alcohol or a solution of alcohol

and water can be used. Further, a suitable binder,

stabilizer, surfactant, pH-adjusting agent, coloring 8 4 27_664

30,048/7, agent, taste-mhsking agent, flavor or chemicals can be added singly or in mixture to water, alcohol or a solution of alcohol and water, and the resulting solu- tion can be.used as the binder liquid. The maximum amount of the binder liquid to be addcd to the nucleus granules and contained therein to form wet nucleus granules can be determined by measuring an angle of repose of the wet nucleus granules containing the binder liquid. That is to say, the angle of repose becomes larger with an increase in the amount of the binder liquid added, and it is difficult to sprinkle the wet nucleus granules in a discretely fLowing state onto the powders when the angle of repose exceeds about 45 degrees. Therefore, the amount of the binder liquid which allows the angle of repose of the wet nucleus granules to take about 40 degrees is re- garded as the maximum amount of the liquid that can be added to and held by the nucleus granules. According to the present invention, the thus obtained wet nucleus granules are sprinkled in a discretely flowing state onto the powders. In sprinkl- Ing the wet nucleus granules, it is desirable to- sprile the granules so that the wet nucleus granules may no form a- layer when they are made to fall, as single-particles, in the discretely flowing state onto

the powders in the suitable pelletizer. According to the capacity and type of the pelletizer, a feeder, such as a vibration feeder or belt feeder, can be used. It is desirable to provide a wire screen having larger opening than the sizes of the nucleus granules at the

30,048/71 tip end of the feeder to effect uniform sprinkling of nucleus

granules and control the rate of flowing.

As an apparatus for keeping the powders in a flow- ing state, any apparatus, for example, a coating pan, a

dish-type pelletizer or drum-type blender, can be used, so long as the apparatus can keep the powders in a flowing

state, and any special apparatus is not required. A balance between the amount of the wet nucleus

granules to be sprinkled and the amount of the powders to

be picked up by the wet nucleus granules and granulated is

particularly important to obtain pellets having the desired

uniform sizes in high yield, and the amount of the powders must be enough to be picked up by the wet nucleus granules..

The powders to be picked up by the wet nucleus

granules and pelletized comprise powders of a drug or powders

of a adjuvant alone or in their mixture, or further contain a surfactant, glidant, binder, pH-adJusting agent, taste-

masking agent, flavor, coloring agent of medicament singly

or in their mixture. It is essential that at least a portion of the component consisting of the powder has a property to

dissolve in the binder liquid which is added onto contained

in the nucleus granules. Further, the glidant is also effective- to make much smoother the surface of the final pellets.

The sizes of the pellets produced according to the present method depend upon the physical properties, sizes

and water content of the nucleus granules, and-the--physical properties of the powders 4 27 6

30,04 8m to be pelletized. For example, spherical pellets

having any desired, uniform size selected from such a

wide range of about 0.1 to 5 =m can be produced by

proper selection and combination of these factors. Furthermore, when a large amount of pellets------

are to be produced according to the present process,

the po-ders to be picked up and the wet nucleus

granules are continuously or intermittently fed to a

rolling type granulator, simultaneously or alternately,

whereas the pellets having the desired size can be

continuously taken out of the granulator.

The pellets prepared from the nucleus-

granules according to the present invention have a

good flowability and good appearance,. and can be used,

as they are, as medicament pellets, or coating can be

readily applied to the pellets .to endow a water-proof

property, enteric property, taste adjustment, smell

adjustment or controlled dissolution of drug to the

pellets.

Now, the present invention will be explained

in detail, referring to examples, but the present

invention is not limited only to these examples.

Example 1 Nucleus granules: granules of colloidal

synthetic silicon dioxide Size of the nucleus granules: 40 50 meshs

liquid added to the nucleus granules: water Amount of the liquid added thereto: ml per 100 g of nucleus granules.

30,04 8 /7 Prescription of powders to be picked up: Sugar powders: 97 parts by weight Gum arabic powders: 2 parts by weight Colloidal synthetic silicon dioxide: 1 part by weight

Said nucleus granules were placed in a suitable vessel, and water was added thereto at the predetermined ratio. The granules were gently stirred and left standing for about 10 minutes. Then, the resulting granules were passed through a 20-mesh wire screen, and blended in a V-type blender for 30 seconds, whereby wet nucleus granules were obtained. On the other hand, 500 g of the powder mixture of the above-mentioned prescription was charged into a dish-type pelletizer (oil-hydraulic pelletizer, Type KS-6 made by Sowa Kinzoku Company, Ltd., Japan) and the pelletizer was rotated at about 40 rpm. Said wet nucleus granules were slowly sprinkled onto-the powders by a vibration feeder during the rotation of the pelletizer. After about 80 grams of the wet nucleus granules were sprinkled, the rolling was continued for a few minutes, and the pellets were dried at 50 0 C for about 18 hours, and classified by sieves. As shown in Table 1, spherical pellets having uniform sizes of 30 40 meshes were obtained in yield of about In place of colloidal synthetic silicon dioxide used in said prescription for the powders to be granulated, white carbon, synthetic aluminum silicate, 27 6

30,048/71 synthetic magnesium silicate, metamagnesium alumino-

silicate, dried aluminum hydroxide gel, and aluminum

hydroxide magnesium hydroxide gel were used

separately,, but similar results were obtained.

Example 2

Nucleus granules: White carbon (Carplex #80, a

trademark of a product made

by Shionogi Seiyaku Co., Ltd.,

Japan) Size of nucleus granules: 40 50 meshes .liquid added to nucleus granules: Water Amount of the liquid added thereto: 140 ml-per-lOO g

of the nucleus granules Prescription of powders to be picked up:

Calcium sulfate: 50 parts by weight Sugar powders: 46-parts by weight Gum arabic powders: 3 parts by weight Colloidal syn'chetic silicon dioxide: 1 part by weight

Wet nucleus granules were prepared in the same manner as in Example 1, and 500 g of the powder mixture of the above prescription was charged into the same apparatus used in Example 1. About 78 g of the wet nucleus granules were sprinkled and pelletized in the same manner as in Example 1. As a result, spherical pellets having sizes of 20 to 40 meshes as shown in Table 1 were obtained in yield of about 85

f13 4276

Example 3 30, 04 8/7 Nucleus granules: Dried aluminum hydroxide gel

(spray-dried product) Size of the nucleus granules: 40 50 meshes

Liquid added to the nucleus granules: Water

Amount of the liquid added thereto: 80 ml per 100 g

of the nucleus granules

Prescription of powders to be picked up:

Sugar powders: 97 parts by weight

Gum arabic powders: 2 parts by weight

Colloidal synthetic silicon dioxide: 1 part by weight

Wet nucleus granules were prepared in the same

manner as in Example 1, and 500 g of the powder mixture of

the above prescription was charged into the same apparatus

as used. in Example 1. About 105 g of the wet nucleus granules

were sprinkled and pelletized in the same manner as in Example

1. As a result, spherical pellets having uniform sizes of

40 meshes as shown in Table 1 were obtained in yield

of about

Example 4

Nucleus granules: Synthetic aluminum silicate

(spray-dried product) Size of the nucleus granules: 60 80 meshes Liquid added to the nucleus granules: Water Amount of the liquid added thereto: 60 ml per 100 g

of the nucleus granules

Prescription of powders to be picked up:

Same as in Example 1

14 427 6

30,04 871 Wet nucleus granules were prepared in the same manner as in Example 1, and 500 g of the same powder mixture as in Example 1 was granulated in the same manner as in Example 1. About 100 g of said wet nucleus granules were sprinkled and pelletized. As a result, spherical pellets having uniform sizes in a narrow range of 30 40 meshes, as shown in Table 1 were obtained in yield of about

Example Nucleus granules: Metamagnesium aluminosilicate (spray-dried product) Size of the nucleus granules: 40 50 meshes Liquid added to the nucleus granules: Water Amount of the liquid added thereto: 70 ml per 100 g of the nucleus granules Prescription of powders to be picked up: Same as in Example 1

Wet nucleus granules were prepared in the same manner as in Example 1, and 500 g of the powders to be picked up was charged into a coating pan having an inner diameter of about 40 cm and two baffles within the pan. While the pan was rotated at about 52 rpm, about 100 g of the wet nucleus granules were slowly sprinkled onto the powders by a vibration feeder and pelletized. As a result, spherical pellets having sizes of 20 40 meshes as.shown in Table 1 were obtained in yield of about 88%.

Example 6 Nucleus granules: Same as in Example Size of the nucleus granules: 50 60 meshes

30,048Sj7t Liquid added to the nucleus granules: 0.3% aqueous solution or Tartrazine Amount of the liquid added thereto: 70 nml per 100 g of the nucleus granules Prescription or powders to be picked up: Chloramphenicol powders: 35 parts by weight Sugar powders: 64 parts by weight White dextrin: 10 parts by weight Colloidal synthetic silicon dioxide- 1 part by weight Wet nucleus granules were prepared In the same manner as In Example 1, and about 100 g of the thus prepared nucleus granules were sprinkledl onto 500 g of the powder mixture of the above prescription and pelletized in the same manner as in Example 1. As a result, spherical pellets having uniform sizes of 20 410 meshes, as shown in Table 2 were' obtained In yield of about Further, when the pellets were almost prepared, about 1.5 g of magnesium stearate was sprinkjled in the same manner as above, whereby the flowability of the pellets was improved and the surface of pellets became smoother. Example 7 Nucleus granules and their sizes: Same as in Example 6 Liquid added to the nucleus granules: Aqueous Isopropyl alcohol solution containing 0.2% Brilliant blue Amount of the liquid added thereto: 180 g per 100 g

of the nucleus granules

3 0,04 8/7 Prescription of powders to be picked up:

Acetylsalcylic acid powders: 6.5 parts by weight

Hydroxypropylmethylcellulose

(through a 150-mesh screen): 20.0 parts by weight

Gum arabic powders: 40.0 parts by weight

Sugar powders: 32.5 parts by weight

Colloidal synthetic silicon dioxide: 1.0 part by weight

Wet nucleus granules were prepared in the same

manner as in Example 1 and about 225 g of the.thus prepared

wet nucleus granules were sprinkled onto 500 g of the powders

of the above prescription in the same manner as in Example

1, whereby spherical pellets having uniform sizes of 30

meshes as shown in Table 2 were obtained in yield of about

Example 8 Nucleus granules and their sizes: Same as in

Example 6

Liquid added to the nucleus granules: 3% polyvinyl

pyrrolidone isopropyl

alcohol solution

Amount of the liquid added thereto: 70 g per 100 g

of the nucleus granules

Prescription of powders to be picked up:

Ascorbic acid fine powders: 50 parts by weight

Polyvinylpyrrolidone

(through 150-mesh screen): 30 parts by weight

Sugar powders: 19 parts by weight

Colloidal synthetic silicon dioxide: 1 part by weight

y1 427690

30,04 8/71 Wet nucleus granules were prepared in the same manner as in Example 1, and about 150 g of the nucleus granules were sprinkled onto 500 g of the powder mixture of said prescription and pelletized. As a result, spherical pellets having uniform sizes of 30 50 meshes as shown in Table 2 were obtained In yield of about The pellets contained about 40% ascorbic acid.

Example 9 Nucleus granules: Synthetic hydrotalcite (Mg Al (OH) 6 2 16 (spray-dried product) 00 3 41H2 0) Size of the nucleus granules: ~40 50 meshes Liquid added to the nucleus granules; Water Amount of the ]Liquid added thereto: 75 mo per 100 g of the nucleus granules Prescription or powders to be picked up: Sugar powders: 39 parts by weight Calcium sulfate: 50 parts by weight Gum arabic powder: 10 parts by weight Colloidal synthetic silicon dioxide: 1 Part by weight Wet nucleus granules were prepared in the same manner as in Example, and 500 g of the powder mixture of the above prescription was charged into the same apparatus as in Example 1. About 1140 g of the wet nucleus granules were sprinkled upon the powder mliture and pelletized in the same manner as in Example 1. As a result, spherical pellets having uniform sizes of 20 410 meshes as shown In Table 3 were ob- tained in yield of about In place of the colloidal synthetic silicon dioxide-

27 690

30,04 8/i7 used in the above prescription of the powder mixture, white carbon, synthetic aluminum silicate, synthetic magnesium silicate, metamagnesium aluminosilicate, dried aluminum hydro- xide gel, and aluminum hydroxide-magnesium hydroxide gel were used, separately, but similar results were obtained.

Example Nucleus granules: Synthetic hydrotalcite (spray-dried product) Size of the nucleus granules: 40 50 meshes Liquid added to the nucleus granules: Water Amount of liquid added thereto: 75 ml per 100 g of the nucleus granules Prescription of powders to be picked up:

Chloramphenicol powders: 35 parts by weight Sugar powders: 54 parts by weight Gum arabic powders: 10 parts by weight Colloidal synthetic silicon dioxide: 1 part by weight

Wet nucleus granules were prepared in the same

manner as in Example 1, and 500 g of the powder mixture of

said prescription was charged into the same apparatus as in

Example 1. About 150 g of the wet nucleus granules were sprinkled in the same manner as in Example 1. As a result, spherical pellets having uniform sizes of 20 40 meshes as shown in Table 3 were obtained in yield of about

4276 90

30,048/71 Table 1

SExample

esh 1 2 3

12 0.2% 0.6% 0.2% 0 0 12 20 1.2 2.0 2.5 1.0 0.3 30 75.3 76.0 54.5 7.1 63.3 40 17.2 12.3 32.3 70.2 25.1 60 1.2 2.8 5.2 13.2 4.9 80 4.8 .9 6.3 }5.3 3.7

Table 2

Example 6 8 Mesh. 7

Particle size 20 2.1% 0 0.1% distribution 20 30 10.4 2.1 0.2 of pelletiz- 30 40 69.7 63.2 42.0 ed pellets 40 50 0.1 11.6 38.7 50 60 8.5 7.9 '8.2 15.1 11.5 8.2 15.1

30,04 8rn Table 3

Example 9 Mesh

Particle size 20 o.8% 1.2% distribution of 20 30 75.9 61.3 pelletized 30 410 13.8 214.2 pellets )40 60 2.5 3.1 80 2.6 41.3

41.4 5.9

Claims (11)

0,048171 THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:--

1. A process for producing pellets, which com- prises adding a binder liquid consisting of water or alcohol, or a solution of water and alcohol, to granules consisting

of at least one of colloidal synthetic silicon dioxide,

synthetic silicate of aluminum and magnesium, aluminum hydroxide gel, aluminum hydroxide magnesium hydroxide gel, aluminum hydroxide-aluminum carbonate gel and synthetic magnesium aluminum hydroxide carbonate thereby to prepare wet nucleus granules, and sprinkling the wet nucleus granules in a discretely flowing state onto powders thereby to produce pellets.

2. A process according to Claim 1, wherein the colloidal synthetic silicon dioxide is white carbon; the synthetic silicates of aluminum and magnesium are synthetic aluminum silicate, synthetic magnesium silicate, metamagnesium aluminosilicate, or dimagnesium aluminosilicate.

3. A process according to Claim 1, wherein the granules to which the binder liquid is added are prepared by spray-drying.

4. A process according to Claim 1, wherein the granules are spherical or nearly spherical granules or

cylindrical or square rod-like granules having a ratio of shorter dimension to longer dimension of 1 1.

5 or less. 22 427690

30,04 8/71 A process according to Claim 1, wherein the binder liquid contains a binder, stabilizer, surfactant, pH-adjusting agent, coloring agent, taste-masking agent, flavor or medicament alone or in mixture.

6. A process according to Claim 1, wherein the binder liquid is added to the nucleus granules in an amount until the wet nucleus granules take an angle of repose of degrees.

7. A process according to Claim 1, wherein the powders comprises powders of a medicament powders or adjuvants only or in mixture.

8. A process according to Claim 7, wherein the powders contain a surfactant, glidant, binder, pH-adjusting agent, taste-masking agent, flavor or coloring agent alone or in mixture.

9. A process according to Claim 1, wherein the granules are selected from synthetic aluminum hydroxide gel, aluminum hydroxide magnesium hydroxide and aluminum hydroxide aluminum carbonate .gel.

A process according to Claim 1, wherein the granules are magnesium aluminum hydroxide carbonate.

11. A process according to Claim 1 substantially as hereinbefore described. 4 276

30,04 8/71 DATED THIS 15TH DAY OF JUNE, 1971.

SUMITOMO CHEMICAL COMPANY, LIMITED. By its Patent Attorneys.

CLEMENT HACK CO. Fellows Institute of Patent Attorneys of Australia.