Cholesterol lowering drink mix compositions

Psyllium husk-containing drink mix compositions comprising psyllium husk, an anion exchange resin, and edible, water soluble salts. The edible, water soluble salts are present at a level sufficient to reduce the gellation rate of the psyllium husk and anion exchange resin-containing composition when dispersed in an aqueous solution.

BACKGROUND OF THE INVENTION 
The present invention relates to drink mix compositions useful for reducing 
serum cholesterol levels comprising psyllium husk, an anion exchange 
resin, and edible, water soluble salts. The salt provides the benefit of 
reducing the gellation rate of the drink mix compositions when dispersed 
in an aqueous solution. Preferred salts are neutral in flavor such that 
the drink mix composition is perceived by the consumer as being 
"unflavored". 
High blood cholesterol levels are associated with life threatening 
cardiovascular diseases. Cholestyramine and colestipol are drugs used in 
treating hypercholesterolemia. These drugs are known as basic anion 
exchange resins. They help to lower blood cholesterol levels apparently by 
binding to bile acids in the intestine. It is believed that this in turn 
causes an increase in hepatic metabolism of cholesterol to replenish the 
bile acids lost to complexation with the anion exchange resins. 
Cholestyramine is usually dosed at four grams, one to six times daily. At 
the present time cholestyramine is commercially available as Questran.RTM. 
and Questran.RTM. Light (manufactured by the Bristol-Myers Company) in a 
four gram unit dose powder packet or in bulk powder, and as Cholybar.RTM. 
(manufactured by Parke Davis) wherein one chewable bar contains four grams 
of cholestyramine. [Physicians Desk Reference, 46th Edition, pages 710-712 
and 1705-1706 (1992).] 
Colestipol is usually administered at five to thirty grams daily given once 
or in divided doses. Colestipol is commercially available under the 
tradename Colestid.RTM. (colestipol hydrochloride granules, manufactured 
by The Upjohn Company). It is sold in a five gram unit dose powder packet 
or in bulk powder. [Physicians Desk Reference, 46th Edition, pages 
2328-2329 (1992)]. 
Recent research has demonstrated that psyllium seed husk fiber is also 
effective in reducing human serum cholesterol levels. In addition, 
psyllium seed husk fiber has been found to be effective in controlling 
blood glucose levels in diabetics and in providing laxation and 
normalization of bowel function. Products containing psyllium seed husk 
are known (for example, Metamucil.RTM., sold by The Procter & Gamble 
Company). 
Drink mix compositions containing psyllium husk and an anion exchange resin 
begin to gel once dispersed in an aqueous solution with an accompanying 
increase in the viscosity of the drink solution. The gellation rate is 
further increased relative to psyllium alone, believed to be due to ionic 
interaction of the anionic psyllium husk with the polycationic anion 
exchange resin in the aqueous solution. The consumer of such drink mix 
suspension must drink the liquid suspension in a relatively short period 
of time (less than about two minutes) in order to avoid having to drink an 
aesthetically unacceptable high viscosity liquid. After this time period 
the solution is likely to be considered too thick to enjoy drinking or too 
difficult to drink. 
One possible way to control the rate of gellation is by using acids to 
reduce the pH of the drink mix solution. However, typical acids can impart 
too strong a flavor (e.g., a sour or bitter flavor) to the solution. This 
is especially a concern at higher acid levels which may be desired to 
maximize the reduction in gellation rate. In addition, the acids must be 
consistent with the flavor system being used in the composition. 
Obviously, a highly acidic medium is not suitable for flavor systems which 
require neutral or basic conditions. Also, except in certain controlled 
circumstances, acids are not suited for use in unflavored systems. 
For these reasons, there continues to be a need for psyllium/anion exchange 
resin-containing drink mix compositions having reduced (slower) gellation 
rates. It has been discovered by the present invention that the gellation 
rate of such drink mix compositions in an aqueous solution can be slowed 
by adding a sufficient amount of an edible, water soluble salt. This 
discovery is useful, for example, for allowing the use of less acid or no 
acid (to reduce or eliminate the acid characteristic of drink 
compositions), to permit a wider variety of flavor systems (including 
"unflavored" versions of such drink mix compositions), and to further 
reduce the gellation rate for compositions containing higher levels of 
acid. 
It is therefore an object of the present invention to provide improved 
drink mix compositions containing psyllium and an anion exchange resin 
(e.g., cholestyramine) having reduced gellation rates in aqueous solution 
and/or improved aesthetics. It is also an object to provide such drink mix 
compositions which are unflavored or are not highly acidic flavored 
systems. 
These and other objects of the present invention will become readily 
apparent from the detailed description which follows. 
All percentages and ratios used herein are by weight unless otherwise 
specified. Screen mesh sizes used herein are based on U.S. standards. 
SUMMARY OF THE INVENTION 
The present invention relates to serum cholesterol lowering drink mix 
compositions. Such compositions comprise: (a) from about 10% to about 90% 
psyllium husk; (b) from about 10% to about 90% of anion exchange resin; 
(c) from about 0.1% to about 50% edible, water soluble salt at a level 
whereby the gellation rate of the drink mix composition in an aqueous 
solution is reduced; and (d) from about 0% to about 90% other excipients; 
and wherein further said compositions are in a form mixable with a liquid 
to form a suspension of the psyllium husk and anion exchange resin.

DETAILED DESCRIPTION OF THE INVENTION 
The drink mix compositions of the present invention are compositions useful 
for reducing serum cholesterol levels containing psyllium and an anion 
exchange resin in any form suitable for mixing with a liquid to form a 
psyllium husk/anion exchange resin suspension for oral consumption. 
Preferred form is a dry powder in bulk or unit dose form which readily 
mixes and disperses in a liquid. The components of the compositions 
according to the present invention, and representative amounts, are 
described in detail as follows. 
Psyllium Husk: 
The psyllium husk used in the present invention is from psyllium seeds, 
from plants of the Plantago genus. Various species such as Plantago 
lanceolate, P. rugelii, and P. major are known. Commercial psyllium husk 
include the French (black; Plantago indica), Spanish (P. psyllium) and 
Indian (blonde; P. ovata). Indian (blonde) psyllium husk is preferred for 
use herein. Also preferred is psyllium husk which is at least about 85% 
pure, more preferably at least about 90% pure, and most preferably at 
least about 95% pure. 
The psyllium husk is obtained from the seed coat of the psyllium seeds. It 
is typical to remove the seed coat from the rest of the seed by, for 
example, slight mechanical pressure, and then to use only the seed coat. 
The seed coat is preferably removed and sanitized by methods known in the 
art. Preferred is sanitized psyllium seed husk having substantially intact 
cell structure, the sanitization having been accomplished by methods such 
as ethylene oxide sanitization and superheated steam sanitization (as 
taught in U.S. Pat. No. 4,911,889, issued Mar. 27, 1990 to Leland et. al., 
the disclosures of which are incorporated herein by reference in their 
entirety). It is also preferred that the psyllium husk herein have reduced 
particle size (as taught, for example, in U.S. Pat. No. 5,149,541, issued 
Sep. 22, 1992, to Leis, Jr. et al., the disclosures of which are 
incorporated herein by reference in their entirety). 
Preferred for use in the present invention compositions is small particle 
size psyllium husk. The term "small particle size psyllium husk", as used 
herein, means that the psyllium husk utilized in compositions of the 
present invention have a substantial amount of small particle size 
psyllium husk such that the psyllium husk comprises psyllium husk particle 
sizes distributed such that more than about 90% is smaller than about 45 
mesh. More preferably, more than about 80% is smaller than about 50 mesh, 
further preferred is more than about 80% is smaller than about 60 mesh and 
most preferably at least about 80% is smaller than about 80 mesh. Further 
preferred particle sizes are distributed as follows: less than about 25% 
larger than about 60 mesh, and at least about 40% smaller than about 80 
mesh. More preferred are particle size distribution of: less than about 
10% larger than about 60 mesh, at least about 40% within th about 80 mesh 
to about 200 mesh, and less than about 50% smaller than about 200 mesh. 
Particle sizes and particle size distributions may be readily determined 
by one of ordinary skill in the art, for example by sieving using an 
Alpine Laboratory Air Jet Sieve (sold by Alpine American Corp., Natick 
Mass. ). 
The drink mix compositions preferably contain from about 10% to about 90%, 
more preferably from about 20% to about 90%, most preferably from about 
25% to about 75%, of psyllium husk. 
Anion Exchange Resin: 
The term "anion exchange resin", as used herein, means any resinous 
material having cationic moieties such that the material is safe and 
therapeutically effective for treating hypercholesterolemia (at a 
reasonable benefit/risk ratio within the scope of sound medical 
judgement). Preferred anion exchange resins useful herein include 
cholestyramine, colestipol, and mixtures thereof. 
Cholestyramine is a strongly basic anion exchange resin which contains 
quaternary ammonium functional groups attached to a styrenedivinylbenzene 
copolymer. [The Merck Index, 10th Edition, published by Merck & Co., No. 
2182 (1983), incorporated by reference herein in its entirety]. 
Cholestyramine resin-containing compositions are available commercially in 
powder form under the trade names Cuemid.RTM. (Merck, Sharp & Dome) and 
Questran.RTM. and Questran.RTM. Light (Bristol Laboratories division of 
Bristol-Myers). Cholestyramine is commercially available as Duolite AP-143 
resin (Rohm & Haas Co.). 
Colestipol is an insoluble, high molecular weight basic anion-exchange 
copolymer of diethylene triamine and 1-chloro-2,3-expoxypropane with 
approximately 1 out of 5 amine nitrogens protonated (chloride form). [The 
Merck Index, 11th edition, published by Merck & Co., No. 2472 (1989), 
incorporated by reference herein in its entirety]. Colestipol is 
commercially available as colestipol hydrochloride granules under the 
trade name Colestid.RTM. (Upjohn). 
The anion exchange resin in the present invention compositions typically 
comprises from about 10% to about 90% by weight of the pharmaceutical 
composition of the present invention, and preferably from about 20% to 
about 90%. Most preferred is the anion exchange resin comprising from 
about 25% to about 75% by weight of the pharmaceutical composition of the 
present invention. 
Edible, Water Soluble Salts: 
The term "edible, water soluble salts" as used herein, means any salt 
material, organic or inorganic, which is soluble in water (under normal 
use conditions for a psyllium/anion exchange resin-containing drink mix 
composition) and having a pKa of greater than about 5, and which is safe 
for ingestion by humans. Examples of edible, water soluble salts include 
magnesium sulfate, calcium chloride, calcium sulfate, calcium citrate 
malate, potassium chloride, sodium chloride, potassium sulfate, sodium 
sulfate, zinc chloride, zinc sulfate, potassium sotbate, and mixtures 
thereof. Preferred are the salts of divalent cations (e.g. calcium, 
magnesium, zinc) and especially those salts of strong inorganic acids 
(e.g., magnesium sulfate, calcium sulfate, calcium chloride, zinc sulfate, 
zinc chloride, and mixtures thereof). 
As used herein, the term "calcium citrate malate" refers to a mixture or 
(preferably) a complex of calcium, citrate and malate. The calcium citrate 
malate may consist of a mixture of calcium citrate and calcium malate, a 
complex of calcium containing citrate and malate ligands, a mixture of a 
calcium salt with citric acid and malic acid, or combinations thereof. 
Calcium citrate malate is a highly bioavailable source of calcium. Calcium 
citrate malate for use herein may be preformed as a powder or can be 
formed in situ. Preferred calcium citrate malate have 
calcium:citrate:malate molar ratios of about 6:2:3 and 4:2:3. Methods for 
making calcium citrate malate are described in the following documents, 
incorporated by reference herein in their entirety: Japanese Patent 
Specification SHO 56-97248, Kawai, published Aug. 5, 1981; U.S. Pat. No. 
4,722,847, issued to Heckert, Feb. 2, 1988; and U.S. Pat. No. 5,186,965, 
issued to Fox et al., Feb. 16, 1993. 
It is necessary for the purposes of the present invention for the amount of 
the the edible, water soluble salt to be present in an amount sufficient 
to reduce the gellation rate of the drink mix composition relative to the 
compositions without the added salt. This is especially important for 
salts of certain organic acids which at certain levels can have the 
unwanted effect of increasing the gellation rate of psyllium alone 
suspensions (i.e., make the solution thicker, faster), but when used at 
other levels may provide the desired benefit of reducing the gellation 
rate according to the present invention. 
Determination of whether the level of salt present in the psyllium 
husk/anion exchange resin-containing composition is at a level whereby the 
gellation rate of the psyllium/anion exchange resin-containing drink mix 
composition in an aqueous solution is reduced, as required by the present 
invention, is readily made by simple experimentation. For example, it is 
possible to compare the rate of viscosity increase for a composition 
containing the salt versus the composition containing the same components 
but not the edible, water soluble salt. If the rate of gellation is slowed 
by the addition of the amount of salt used, a sufficient level of the 
salt(s) as taught by the present invention is present. Methods and 
equipment for measuring gellation rates and viscosity of liquids are 
known, and such measurements and determinations can easily be made by one 
skilled in the art. For example, the Brookfield Viscometer may be used as 
is exemplified hereinafter. 
Compositions of the present invention therefore may comprise from about 
0.1% to about 50% edible, water soluble salts, preferably from about 0.1% 
to about 20%, and more preferably from about 0.5% to about 5% by weight of 
the drink mix composition. 
Other Excipients: 
Other excipients in the compositions of the present invention must be safe 
for oral administration to humans, and may be chosen by one of ordinary 
skill in the art as appropriate for the drink mix form and use intended 
for the product. Psyllium-containing drink mix products, methods for 
making, and other excipients useful for these products, are described more 
fully, for example, in U.S. Pat. No. 4,459,280, to Colliopoulos et al., 
issued Jul. 10, 1984; U.S. Pat. No. 4,548,806, to Colliopoulos et al., 
issued Oct. 22, 1985; U.S. Pat. No. 4,321,263, to Powell et al., issued 
Mar. 23, 1982; and U.S. Pat. No. 4,828,842, to Furst et al., issued May 9, 
1989; all of which are incorporated by reference herein in their entirety. 
The drink mix compositions of the present invention comprise from about 0% 
to about 90%, preferably from about 1% to about 60%, and more preferably 
from about 2% to about 50%, of other excipients. 
Most preferred are products of the present invention in dry powder form 
suitable for mixing in a liquid to form a psyllium/anion exchange 
resin-containing drink. Preferred other excipients for such powder forms 
are known and are also described in detail, for example, in U.S. Pat. Nos. 
4,459,280 and 4,548,806, incorporated hereinbefore by reference. Preferred 
are such powders (preferably sugar free) comprising maltodextrin. Also 
especially preferred are powders comprising agglomerates of psyllium 
and/or coated psyllium, especially agglomerated with maltodextrin and/or 
sucrose. 
Agglomerating materials preferred for use herein are known. These 
agglomerating materials include those selected from the group consisting 
of water dispersible hydrolyzed starch oligosaccharide, mono-saccharide, 
di-saccharide, polyglucose, polymaltose, and mixtures thereof. 
Compositions of the present invention preferably comprise from about 0.5% 
to about 20% of agglomerating material coating on said psyllium husk, 
preferably from about 1% to about 10%, and more preferably from about 1% 
to about 5%. 
Hydrolysis of starch may be accomplished by a reaction of either acid, 
enzymes (e.g., alpha-amylase, beta-amylase or amyloglucosidase), or a 
combination of the two either together or reacted in series. The 
hydrolysis will follow different pathways depending on whether acids or 
enzymes are used. The result is a mixture of oligosaccharides which may be 
separated for their different properties. The resulting separated water 
dispersible (preferably soluble) hydrolyzed starch oligosaccharides are 
classified by their reducing sugar content, i.e., the mono- or 
di-saccharides such as glucose or fructose. The percent reducing sugar 
content in the particular hydrolyzed starch oligosaccharide is measured on 
a weight/weight basis as the Dextrose Equivalent (or "D.E."). Hydrolyzed 
starch oligosaccharides with a D.E. of from 0 to 20 are called 
maltodextrins. The solid maltodextrins have low to moderate sweetness, low 
to moderate hygroscopicity, solubility in water and alcohol, and have 
reduced browning. Above a D.E. of about 20 the hydrolyzed starch 
oligosaccharides are called syrup solids. The syrup solids are soluble but 
have a more noticeable sweetness and are more hydroscopic. Above a D.E. of 
about 30, the syrup solids become less desirable for use herein. A 
preferred water dispersible hydrolyzed starch oligosaccharide therefore 
has a D.E. of from about 0 to about 30. A preferred maltodextrin has a 
D.E. of from about 5 to about 20, more preferably about 10 (i.e., a 
reducing sugar content ratio of 10% w/w of the oligosaccharide). 
The mono-saccharides are those carbohydrates that in general are 
aidehyde-alcohols or ketone alcohols that are a hexose or pentose and have 
a sweet taste. They are readily soluble in water and form crystalline 
solids. Examples of the di-saccharides are those carbohydrates which yield 
two mono-saccharides on hydrolysis. Examples of di-saccharides are 
lactose, sucrose and maltose. 
Preferred compositions of the present invention comprise an edible acid as 
part or all of the optional other excipients. The term "edible acids", as 
used herein, means any water soluble acid material having a PK.sub.a of 
less than about 5, preferably within the range of from about 2 to about 5, 
and is safe for ingestion by humans. Examples of edible acids include, but 
are not limited to, citric acid, ascorbic acid, malic acid, succinic acid, 
tartaric acid, phosphoric acid, monopotassium phosphate and mixtures 
thereof. Preferred are ascorbic acid, phosphoric acid, malic acid, and 
citric acid, with citric acid being most preferred. 
The compositions of the present invention typically comprise from about 
0.1% to about 25% edible acid, preferably from about 0.1% to about 10%, 
and more preferably from about 0.1% to about 5%. Also preferred are 
compositions containing less than about 2% edible acid, more preferably 
less than about 1% edible acid, and most preferably less than about 0.5% 
edible acid. 
Preferred compositions of the present invention are those which have some 
or all of the edible acid coated on the psyllium husk, and further 
preferably such that the psyllium husk is agglomerated. Agglomerated 
psyllium husk is described in European Patent Application No. 412,604, 
published Feb. 13, 1991, and incorporated by reference herein in its 
entirety. Preferred single layer coating of the psyllium husk is achieved 
by utilizing equipment (referred to herein as single pass fluidizing 
powder wetting apparatus) which operates preferably by dropping a dry 
blend psyllium-containing material through a highly turbulent annular zone 
formed by a cylindrical wall and a rotating shaft with variously pitched 
attached blades. An edible acid-containing solution is preferably sprayed 
into this zone to contact a dry psyllium-containing blend. The resulting 
coated, preferably agglomerated, psyllium husk is dropped to a fluid bed 
dryer where the added solvent is removed. An example of this equipment is 
the Bepex Turboflex Model No. TFX-4 (sold by Bepex Corporation; 
Minneapolis, Minn.) with a six square foot bed vibrating fluid bed dryer 
(sold by Witte Corporation, Inc.; Washington, N.J.). 
The psyllium-containing blend preferably comprises from about 25% to about 
100% of psyllium. Optional components for the psyllium-containing blend 
include, but are not limited to, edible acid, sweetening agents 
(preferably low calorie sweetening agents, including, but not limited to, 
aspartame, saccharin, cyclamate, acesulfame, and mixtures thereof), 
coloring agents, agglomerating materials (especially maltodextrin), 
dietary fibers such as brans (e.g., wheat bran; oat bran; rice bran)and/or 
pharmaceutical agents (e.g., nonsteroidal anti-inflammatories; aspirin; 
sennosides). Some or all of the edible, water soluble salt and/or anion 
exchange resin may also be included in the psyllium-containing blend. As 
noted hereinbefore, it is preferred that the psyllium-containing blend be 
dry, but it is possible to utilize suitable solvents (e.g., alcohols 
and/or water) if one is careful, especially if water is utilized, not to 
cause substantial hydration and swelling of the psyllium, since this is 
expected to adversely affect the rate at which psyllium husk can interact 
with water or other fluids. 
The solution mixture preferably comprises one or more edible acids to be 
sprayed onto the psyllium-containing blend along with also preferably 
comprising some or all of the edible, water soluble salt. This may be 
prepared by selecting a liquid (e.g., alcohol and/or water) as appropriate 
for the materials being coated onto the psyllium husk. However, it is 
preferred that water be utilized. Preferred is also spraying the solution 
mixture onto a dry psyllium-containing blend. Preferably, when a spraying 
technique is used, the solution mixture is an aqueous solution comprising 
from about 1% to about 50% (preferably from about 10% to about 25%) of the 
edible, water soluble salt and also from about 0% to about 50% (preferably 
from about 1% to about 20%) of edible acid. It is also optionally possible 
to repeat the coating and drying steps, thereby building up a coating on 
the psyllium husk which comprises several thin layers of the materials. In 
addition, other optional materials may be present in the solution mixture, 
such as coloring agents, pharmaceutical agents, and mixtures thereof. 
Other methods for preparing compositions according to the present invention 
include dry blending the ingredients and other means of multiple layer 
coating of the psyllium husk. The latter may be accomplished by using, for 
example, fluid bed agglomerating equipment such as the Fluid Air, Inc. 
Model 0300 Granulator-Dryer. 
Method of Treatment: 
The method of treatment herein comprises orally administering to a human or 
lower animal patient in need of having a lowered blood cholesterol level a 
safe and effective amount of an aqueous liquid suspension of a 
psyllium/anion exchange resin-containing composition according to the 
present invention. The term "safe and effective amount", as used herein, 
means an amount of a psyllium fiber/anion exchange resin composition high 
enough to significantly positively modify the hypercholesterolemic 
condition being treated, but low enough enough to avoid serious side 
effects (at a reasonable benefit/risk ratio), within the scope of sound 
medical judgement. The safe and effective amount will vary with the age 
and physical condition of the patient being treated, the nature of the 
condition, the duration of treatment, the nature of concurrent therapy, 
and like factors within the knowledge and expertise of the attending 
physician. However, a patient in need of such treatment will typically 
receive from 4 g to about 24 g of the anion exchange resin daily and from 
1 g to 30 g of psyllium husk. 
The following examples further describe and demonstrate embodiments within 
the scope of the present invention. These examples are given solely for 
the purpose of illustration and are not to be construed as limitations of 
the present inventions as many variations thereof are possible without 
departing from the spirit and scope. 
EXAMPLE 1 
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EXAMPLE 1 
Components % in formula 
______________________________________ 
Psyllium Mucilloid.sup.a) 
40.60 
Cholestyramine Resin.sup.b) 
45.10 
Citric Acid 7.30 
Orange Flavor 3.40 
Sodium Citrate 1.70 
Aspartame 0.62 
Calcium Chloride 1.10 
Coloring 0.09 
______________________________________ 
.sup.a) Psyllium husk of particle size approximately 100% through 80 mesh 
.sup.b) Supplied by Rohm & Haas. 
The composition is prepared by dry blending the ingredients. Consumption of 
8.86 g of this composition twice daily by a person in need of cholesterol 
reduction, as a suspension in 8 ounces of water, provides 4 g of 
cholestyramine and 3.6 g of psyllium effective for reducing serum 
cholesterol. 
EXAMPLE 2 
To evaluate the value of adding various levels of edible, water soluble 
salts, the following comparative testing was conducted to evaluate the 
rate of viscosity increase for small particle size psyllium husk and 
cholestyramine suspended in a citric acid solution. The suspensions were 
prepared using the following components: 
______________________________________ 
Weight %.sup.d) 
Suspension #: 
1 2 3 4 5 
______________________________________ 
psyllium.sup.a) 
45.6 44.8 44.3 44.8 44.3 
cholestyramine.sup.b) 
53.3 52.5 51.9 52.5 51.09 
citric acid.sup.c) 
1.11 1.09 1.08 1.09 1.08 
CaCl.sub.2 .multidot.2H.sub.2 O 
-- -- -- 1.64 2.70 
MgSO.sub.4 .multidot.7H.sub.2 O 
-- 1.64 2.70 -- -- 
______________________________________ 
.sup.a) Approximately 100% smaller than about 80 mesh; 8.2 g added in eac 
suspension. 
.sup.b) 9.6 g added in each suspension. 
.sup.c) Citric acid; 20 g of 1% aqueous citric acid (by weight), was firs 
diluted with water to give a total weight of 480 g. 
.sup.d) Weight % in the table is prior to water addition. 
A dry blend of all the components (except for citric acid which was 
predissolved in the water) was added to the 480 g citric acid solution 
with 30 seconds of stirring in a 600 ml beaker. The weight of 
cholestyramine and psyllium added was kept constant in each suspension. 
[The weight % of cholestyramine and psyllium changed across the various 
suspensions due to the presence or absence of CaCl.sub.2 or MgSO.sub.4.] 
The viscosity of the suspension was measured using a Brookfield Viscometer 
(Model #RVT; Spindle 1; 10 RPM). The viscosity of the suspensions at 
various times were as follows: 
______________________________________ 
Suspension #: 
1 2 3 4 5 
______________________________________ 
Time (seconds) 
Viscosity (centipoise) 
60 412 385 338 360 300 
90 497 425 420 420 370 
120 587 500 502 505 450 
150 667 590 582 590 505 
______________________________________