FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10 and rule 13]
MANUFACTURING PROCESS OF HYDROXYETHYL
STARCH (HES -130)
CLARIS LIFESCIENCES LIMITED
Claris Corporate Headquarters, Nr.Parirnal Crossing,
Ellisbridge, Ahmedabad - 380 006,
GUJARAT, INDIA
The following specification particularly describes the invention and the manner
in which it is to be performed.

1) FIELD OF INVENTION
[0001] The present invention relates to an improved process for making an advance Hydroxy Ethyl Starch - 130.
2) BACKGROUND OF THE INVENTION
[0002] A. Intravenous HES - 130 (Tetra starch) therapy
[0003] Hydroxy Ethyl Starch - 130 is necessary as plasma volume expanders in various critical situations like Surgery, Trauma, Spinal Preloading in Spinal anesthesia, Cardiac Priming during cardiac surgeries, Blood Saving, Burns and Sepsis etc.
[0004] B. Potential Side Effects of IV HES - 130 (Tetra starch) Therapy
[0005] Hydroxy Ethyl Starch is available with various molecular weights. Its adverse effects shall simultaneously increase with the rise in its molecular weight. It meagerly affects the normal function of kidney and may also causes anaphylactic reactions. See, Volume therapy in Cardie Surgery, j.Boldt 2005: 104-116.
[0006] C. Purity of Hydroxy Ethyl Starch
[0007] Purity of Hydroxy ethyl starch - 130 is carried out by various purity tests like pH. specific optical rotation, solubility, chloride content, heavy metals, loss on drying, Residue on ignition. Ethylene glycol, molar substitution, average molecular weight. nitrogen content, methanol content, clarity of the solution, % transmittance, inherent viscosity, arsenic content, bacterial endotoxin, total viable aerobic count/total micro organisms etc.
[0008] A resultant of Hydroxy Ehtyl Starch - 130 (tetra starch) comprising a narrower molecular weight distribution may yield a safer and more efficacious therapy. There exists a need for Hydroxy Ehtyl Starch - 130 (tetra starch) preparative method that results in a product with low coast, narrower molecular weight and distribution as compared to existing compositions.

3) SUMMARY OF THE INVENTION
[0009] According to one embodiment of the invention, the process of preparing hydroxy ethyl Starch -130 (tetra starch) is already provided, which is substantially free of excipients, comprising the following steps:
[0010] The waxy maize starch is reacted with Hydrochloric acid and Sodium hydroxide at a selected temperature, molarity and pH.
[0011] According to step [0010], the hydrolyzed starch is mixed with Ethylene oxide and hydrocholoric acid at a selected temperature and selected pH. This step is also known as Ethylation step.
[0012] According to another embodiment of the invention, Ethylated starch is reacted with methanol at a specific volume of methanol for the specific time period. This step is also known as precipitation step.
[0013] According to another embodiment of the invention, precipitated tetra starch is reacted with activated charcoal, hydrochloric acid and sodium hydroxide at a selected temperature and pH. This step is also known as charcoalisation.
[0014] According to another embodiment of the invention, the solution of tetra starch is filter through 30 KD cassettes. This will remove the particles, which are having more then 30,000 molecular weight. The step is also known as Ultra filtration step.
[0015] According to one embodiment of the invention, the ultra filter tetra starch solution is taken in spray dryer at a maintain air duct temperature and maintain powder duct temperature. This step is also known as spray drying.
[0016] As per the step [0010], the selected temperature is ranging from 49 °C to 50 °C.
[0017] As per the step [0010], the selected molarity is ranging from 0.90 M to 0.91 M.
[0018] As per the step [0010], the selected pH is ranging from 12.00 to 12.70 M.

[0019] As per the step [0011], the selected temperature is ranging from 48 °C and 52 °C.
[0020] As per the step [0011]; the selected pH is ranging from 12.00 to 12.50 M.
[0021] As per the step [0012], the selected volume of methanol is range from 2000 liters to 3000 liters.
[0022] As per the step [0012], the selected time is ranging from 2 to 4 hours.
[0023] As per the step [0013]. the selected temperature is ranging from 80 °C to 85 °C.
[0024] As per the step [0013], the selected pH is ranging from 5.50 to 6.00 pH.
[0025] As per the step [0015]. the selected maintain air duct temperature is ranging from 155°Ctol70°C.
[0026] As per the step [0015], the selected maintain powder duct temperature is ranging from 80 °C to 88 °C.
Definitions:
[0027] The term "Hydrolysis" is defining chemical reaction or process in which a chemical compound reacts with water. This is the type of reaction that is used to break down polymers. Water is added in this reaction. Eample of hydrolysis is the hydrolysis of waxy starch in the presence of hydrochloric acid.
[0028] The term "Precipitation" is defined as the formation of a solid in a solution during a chemical reaction. When the chemical reaction occurs the solid formed is called the precipitate. This can occur when an insoluble substance, the precipitate, is formed in the solution due to a reaction or when the solution has been supersaturated by a compound. Example of precipitation is the precipitation of tetra starch by reacting Ethylated solution of starch with methanol.
[0029] The expression "Filtration" is defined as A treatment process, under the control of qualified operators, for removing solid (particulate) matter from water by

means of porous media such as sand or a man-made filter; often used to remove particles that containing pathogens. Example of filtration is the filtration of tetra starch to remove chloride content from the initial solution.
[0030] The expression "drying" is defined as a mass transfer process resulting in the removal of water moisture or moisture from another solvent, by evaporation from a solid, semi-solid or liquid (hereafter product) to end in a solid state. Example of drying is the drying of ultra filter solution.
STATEMENT OF THE INVENTION
A process for preparation of hydroxyethyl starch (HES) having molecular weight between 1,10,000 to 1,50,000 daltons and molar substitution of 0.35 to 0.45 comprising;
a) acid hydrolysis of waxy starch suspended in water at temperature of 45°C to 50°C. then adjusting the pH to 9.0 to 12.0;
b) ethylating the hydrolyzed starch at step (a) with 10 to 20% (by weight of starch) ethylating agent by heating at temperature 48°C to 50°C;
c) subjecting the slurry obtained in step (b) for precipitation by addition of organic solvent;
d) addition of activated charcoal to remove the colour and impurity;
e) ultra filtration and spray drying to obtain the hydroxyethyl starch having molecular weight 1,10,000 to 1,50,000 daltons with molar substitution of 0.35 to 0.45.
The waxy starch is selected from maize starch, cornstarch and potato starch and acid hydrolysis is carried at temperature of 49°C to 50°C with a slurry molarity of 0.2 to 1M which adjusted by addition of 8 N HC1 for duration of 4 to 12 hours. The ethylating agent for ethylation is selected from ethylene oxide and 2-chloro ethanol. The heating in step (b) is carried till exhaust of free starch completely and then cooled to 42 °C to 45 °C with adjusting the pH between 4.0 to 7.0. The organic solvent for precipitation is selected from the group of iso-propyl alcohol, methyl alcohol, ethyl alcohol, acetone, dimethyl sulfoxide and n-propyl alcohol preferably iso-propyl alcohol. The ultra filtration is carried with 1-50 KD cassettes to remove all compounds which are below 30,000 molecular weight and the ultra filtration is carried out until the chloride content is less then 0.5 %.

4) DETAILED DESCRIPTION OF THE INVENTION
[0031] The present invention provides a process for the preparation of Hydroxy Ethyl Starch (Tetra Starch), which is mainly use as a blood volume enhance in the body.
[0032] Waxy starch
The waxy starch, which is used as initial material for the production of Hydroxy Ethyl Starch (Tetra Starch), is founded from maize material. The other sources which may used for the same production are corn starch, potato starch etc.
[0033] Hydrocholoric acid
The Hydrocholoric acid can be used as different names like Chlorohydric acid; Hydrochloric acid; Hydrochloric Acid; Hydrochloride; Hydrogen chloride; Hydrogen chloride (acid); HYDROGEN CHLORIDE GAS ONLY; Muriatic acid; Spirits of salts. Mainly 8 N Hydrocholoric acid is used for the production of Hydroxy ethyl starch (tetra starch).
[0034] Sodium Hydroxide
The term " Sodium Hydroxide " as employed here may also be used as different names like Augus Hot Rod; Caustic soda; lye. caustic; Lye; Sodium hydrate; Sodium hydroxide; soda lye; White Caustic.
[0035] Ethylene oxide
The term " Ethylene oxide " as employed here may also be used as different names
like 2-epoxyethane; Alpha,beta-oxidoethane; amprolene; anprolene; anproline;
Dihydrooxirene; dimethylene oxide; E.O.; Epoxyethane; Ethene oxide; Ethox;
Ethylene Oxide; Ethylene Oxide ; ETO; fema no. 2433; merpol; oxacyclopropane;
>
Oxane; oxidoethane; oxirane; oxyfume; oxyfume 12; Qazi-ketcham; T-GAS.
[0036] Methanol
The term " Methanol" as employed here may also be used, as different names like
Carbinol; colonial spirit; Columbian spirit; Columbian spirits; Methanol; Methanol;
METHYL ALCOHOL (METHANOL); methyl hydroxide; Methylol;
monohydroxymethane; pyroxylic spirit; Wood; Wood alcohol: wood naphtha; wood
spirit.

[0037] The hydrolysis is carried out by reacting waxy maize starch with Hydrochloric acid and sodium hydroxide at a selected temperature, pH and molarity.
[0038] A water for injection is taken in a hydrolysis tank and cool it at a selected temperature.
[0039] As the description [0038], the quantity of water for injection is ranged from 350 to 400 liters.
[0040] As per the [0039], the selected temperature is ranged from 45 °C to 50 °C.
[0041] As per the description [0039], the final volume is made up to 525 to 550 liters with continuous steering.
[0041] After producing slurry the temperature can be maintained between 49 °C to 50°C.
[0042] As per the description [0041], the temperature is ranging from 20 °C to 80 °C.
[0043] The molarity is ranging from 0.90 to 0.91 by adding 8 N HC1 in the slurry, which is produce through description [0042].
[0044] The stirring is continuous in the slurry, which is produce through description for a particular time.
[0045] As per the description [0044], the selected particular time is ranging from 5.15 to 5.45 hours.
[0046] As per the description [0045]. the selected time is also ranged from 4 to 12
hours.
[0047] The slurry as per the description [0046] is cooled up to 40 °C to 42 °C.
[0048] The pH of the slurry, which is prepared as per description [0047], is between 12.00 to 12.20 by adding 4N sodium hydroxide, which may range from 9.0 to 13.0 pH.

[0049] As per the description [0048], the slurry of hydrolyzed starch is taken in ethylation tank and allows it to react with a selected quantity of Ethylene oxide (2-chloro ethanol) at a selected time.
[0050] As per the description [0049], the selected time is between 38 °C to 40 °C.
[0051] As per the description [0050]. after adding ethylene oxides raise the temperature up to 48 °C to 50 °C.
[0052] As per the description [0051], the temperature is ranged from 20 °C to 80 °C.
[0053] As per the description [0052]. the temperature of slurry is maintained till free starch is removed.
[0054] As per the description [0053], the slurry is cooled up to 42 °C to 45 °C.
[0056] As per the description [0055]. the slurry pH is ranged from 4.80 to 5.50 by adding 8N Hydrochloric acid.
[0057] As per the description [0056], the pH of the slurry may range from 4.0 to 7.0.
[0058] As per the description [0057], Ethylated solution of starch is under gone through the three consecutive steps of precipitation process.
[0059] As per the description [0058], in the first extraction step, selected amount of isopropyl alcohol is mixed with ethylated solution of starch with stirring.
[0060] As per the description [0059], the selected amount of isopropyl alcohol is ranged from 575 to 625 liters.
[0061 ] As per the description [0060], instead of isopropyl alcohol various other alcohols may also used like methyl alcohol, ethyl alcohol, acetone, dimethyl sulfoxide and n- propyl alcohol etc,
[0062] As per the description [0060], the slurry is allowed to settle for the selected time. [0063] As per the description [0062], the selected time is 30 minutes and then decanted the upper layer of the solution.

[0064] As per the description [0063], in the second extraction step, the lower layer is treated with selected amount of water for the selected times.
[0065] As per the description [0064], the selected amount of water is ranged from 75 to 125 liters.
[0066] As per the description [0065], the selected time is 30 minutes.
[0067] As per the description [0066]. the isopropyl alcohol is mixed with slurry and still for a selected time.
[0068] As per the description [0067], the selected time is 30 minutes and then decanted the upper layer of the solution.
[0069] As per the description [0068], in the third extraction step, the lower layer is treated with selected amount of water for the selected times.
[0070] As per the description [0069], the selected amount of water is ranged from 75 to 125 liters.
[0071] As per the description [0070], the selected time is 30 minutes.
[0072] As per the description [0071]. the isopropyl alcohol is mixed with slurry and still for a selected time.
[0073] As per the description [0072], the selected time is 30 minutes and then decanted the upper layer of the solution.
[0074] As per the description [0073], in the fourth extraction step, the lower layer is treated with selected amount of water for the selected times.
[0075] As per the description [0074], the selected amount of water is ranged from 75 to 125 liters.
[0076] As per the description [0075], the selected time is 30 minutes.
[0077] As per the description [0076], the isopropyl alcohol is mixed with slurry and still for a selected time.

[0078] As per the description [0077], the selected time is 30 minutes and then decanted the upper layer of the solution.
[0079] As per the description [0078]. in the fifth extraction step, the lower layer is treated with selected amount of water for the selected times.
[0080] As per the description [0079], the selected amount of water is ranged from 75 to 125 liters.
[0081] As per the description [0080]. the selected time is 30 minutes.
[0082] As per the description [0081], the isopropyl alcohol is mixed with slurry and still for a selected time.
[0083] As per the description [0083], the selected time of the slurry is 30 minutes and then decanted the upper layer of the solution.
[0084] As per the description [0083]. the precipitated of tetra starch is taken for the charcoalisation process.
[0085] As per the description [0084]. in the charcolisation step the slurry is stirred with specific volume of water for injection and for the specific time.
[0086] As per the description [0085], the specific volume of water is ranged from 400 to 500 liters.
[0087] As per the description [0086], the specific time is 30 minutes for the slurry.
[0088] As per the description [0087]. the slurry temperature is increased up to 80 °C and 85 °C for the evaporation of the excess methanol.
[0089] As per the description [0088]. the final volume is made up with water for injection by using specific volume.
[0090] As per the description [0089], the specific volume is ranged from 2000 to 2200 liters.

[0091] As per the description [0089], in the slurry specific volume of activated charcoal is added.
[0092] As per the description [0091]. the specific volume of activated charcoal is ranged from 5 to 10 kgs.
[0093] As per the description [0092]. while stirring the slurry the pH is adjusted
between
4.0 to 7.0 by adding 8N Hydrochloric acid.
[0094] As per the description [0093]. the slurry is pass through filter pads and clarity-is observed.
[0095] As per the description [0094], the slurry is passed through 1.0u filter and transfers the solution to ultra filtration tank.
[0096] As per the description [0095], the slurry is passed from 30 KD cassettes. The number of cassettes can be vary like 1, 2, 5, 10, 20, 25, 50 Kilo Dalton cassettes.
[0097] As per the description [0096]. the ultra filtration of slurry is carried out until the chloride content is less than 0.5% and until the solution concentration is made up to 15% to 20%.
[0098] As per the description [0097], the initial slurry volume is between 2000 to 2200 liters while after filtration the volume is goes down up to 900 to 700 liters.
[0099] As per the description [0098]. after filtration the next step is spray drying by using 155 °C to 170°C air duct and 80 °C to 88 °C powder duct temperature.
[0100] As per the description [0099], the range of air duct temperature is 140 °C to 185 °C and 70 °C to 90 °C for powder duct temperature.
[0101] As per the description [0100]. after completing drying step the product is collected in a suitable container.

Example:
The process of preparing hydroxyethyl starch, of molecular weightl,10,000 to
1.50,000 dalton and molar substitution of 0.35 to 0.45; consisting steps of.
i) Acid Hydrolysis of Waxy starch suspended in water at low acid pH and temperature
of 45°C to 50°C, by adjusting the molarity of the slurry 0.2M to l.OM with 8N
hydrochloride; after hydrolysis of starch pH of slurry is adjusted 9.0 to 12.0 with 4N
sodium hydroxide;
ii) Ethylation of hydrolyzed starch with Ethylene oxide; about 10% to 20% of starch
weight at a selected temperature 48°C to 50°C;
iii) solvent precipitation in Isopropyl alcohol;
iv) charcoalisation to remove the colour and impurity with activated charcoal;
v) ultra filtration and spray drying.
Step i) Acid Hydrolysis of Waxy starch consists of following steps:
a) take 200kg to 300kg waxy maize starch, cornstarch or potato starch;
b) take 350 to 400 iiters water for injection in hydrolysis tank and cool the water tank at a selected temperature;
c) the selected temperature ranges from 45 °C to 50 °C;
d) the final volume shall be made in a range of 525 to 550 liters with water for injection;
e) the slurry is heated up to 49 °C to 50 °C temperature:
f) the molarity of the slurry is adjusted between 0.20 and 1.0 M by adding 8N Hydrochloric acid;
g) the slurry is continuously stirred throughout the addition 8N Hydrochloric acid and maintained the temperature between 49 °C to 50 °C at a selected time between 4 to 12 hours:
h) the slurry is cooled up to 40 °C to 42 °C;
i) the pH of slurry is adjusted between 9.00 to 12.00 by adding 4N Sodium hydroxide.
Step ii) Ethylation of hydrolyzed starch consists of following steps:
a) the hydrolyzed starch is taken in ethylation tank and mixed 20kg to 40kg of Ethylene oxide, at a selected temperature;
b) instead of Ethylene oxide, 2-chloro Ethanol is also used;

c) the slurry is heated at 48 °C to 50 °C temperature till free starch is completely remove;
d) the slurry is cooled at 42 °C to 45 °C at 4.0 to 7.0 pH by adding 8 N Hydrochloric acid;
Step iii) precipitation consists of following steps:
a) as the first step of precipitation, the slurry is mixed up with constant stirring
the selected volume of isopropyl alcohol in ethylation solution;
b) instead of isopropyl alcohol, methyl alcohol, ethyl alcohol, acetone, dimethyl
sulfoxide or n-propyl alcohol may be used;
c) the solution is stirred to mix it properly with isopropyl alcohol;
d) the solution is allowed for 30 minutes settlement and then decants the upper layer;
e) as the second step of precipitation, add selected volume of water and stir it for 30 minutes;
f) the selected quantity of isopropyl alcohol is added and stirs to mix it well:
g) the selected quantity of isopropyl alcohol ranges from 325 to 375 liters;
h) allow the slurry for 30 minutes and decent the upper layer;
i) and third step of precipitation, add selected quantity of water in lower layer and still it for 30 minutes; - j) the selected quantity of water is 75 to 125 liters;
k) add selected quantity of isopropyl alcohol in the slurry and mix it well;
1) allow slurry to settlement for 30 minutes and decent the upper layer;
m) the solution is mixed a selected quantity of isopropyl alcohol and stir to mix up
isopropyl alcohol;
n) allow the solution for about 30 minutes to settlement and decent the upper
layer;
o) the fifth step of precipitation, add selected amount of water from lower layer
and stir it for 30 minutes;
p) in the same solution a selected quantity of isopropyl alcohol is stirred to mix it
well;
q) the solution is settle for 30 minutes and decent the upper layer.

Step iv) Charcoal addition consists of following steps:
a) take the slurry in charcoalisation vessel and mixed it with a specific quantity of water for injection for 30 minutes;
b) the specific quantity of water for injection ranges from 400 ml to 500 ml:
c) the temperature is increased up to 80 °C to 85 °C to evaporate excess isopropyl alcohol;
d) the final volume of the solution is made up to 2000 to 2200 liters with water for injection;
e) 5 to 10 kilograms of activated charcoal is mixed it with the solution;
f) the pH is adjusted between 4.0 to 7.0 by using 8N hydrochloric acid and 4N sodium hydroxide;
g) circulate the solution from filter pads till no fine particles of charcoal should be observed and then check the clarity of solution visually;
h) the filtration is carried out by using 1.0 u size and then transfer the solution to ultra filtration tank.
Step v) ultra filtration and spray drying consists of following steps:
a) the solution is filter through 30 Kilo Dalton cassettes to remove all compounds, which are below 30.000 molecular weight;
b) the cassettes size ranges from 1, 2, 5, 10. 20, 25, 50 kilo Dalton;
c) the ultra filtration is carried out until the chloride content is less then 0.5 %:
d) the solution is concentrated up to 15 % to 20 %:
e) the initial volume of the solution is 2000 to 2200 liters and the final volume ranges from 700 to 900 liters;
f) the solution is taken in spray dryer and dried it at a selected air duct temperature and a selected powder duct temperature;
g) a selected air duct temperature ranges from 155 °C to 170 °C and a powder duct temperature ranges from 70 °C to 90 °C.

We claim,
l.A process for preparation of hydroxyethyl starch (HES) having molecular weight between 1,10,000 to 1,50,000 daltons and molar substitution of 0.35 to 0.45 comprising:
a) acid hydrolysis of waxy starch suspended in water at temperature of 45°C to 50°C, then adjusting the pH to 9.0 to 12.0;
b) ethylating the hydrolyzed starch at step (a) with 10 to 20% (by weight of starch) ethylating agent by heating at temperature 48°C to 50°C;
c) subjecting the slurry obtained in step (b) for precipitation by addition of organic solvent;
d) addition of activated charcoal to remove the colour and impurity;
e) ultra filtration and spray drying to obtain the hydroxyethyl starch having molecular weight 1,10,000 to 1,50.000 daltons with molar substitution of 0.35 to 0.45.
2.T he process for preparation of hydroxyethyl starch as claimed in claim 1. wherein the waxy starch is selected from maize starch, cornstarch and potato starch.
3.T he process for preparation of hydroxyethyl starch as claimed in claim 1. wherein the acid hydrolysis is carried at temperature of 49°C to 50°C.
4.T he process for preparation of hydroxyethyl starch as claimed in claim 1, wherein the acid hydrolysis is carried at a slurry molarity of 0.2 to 1M which adjusted by addition of 8 N HC1.
5.T he process for preparation of hydroxyethyl starch as claimed in claim 1. wherein the acid hydrolysis is carried for duration of 4 to 12 hours.
6.T he process for preparation of hydroxyethyl starch as claimed in claim 1, wherein ethylating agent is selected from ethylene oxide and 2-chloro ethanol.

7.T he process for preparation of hydroxy ethyl starch as claimed in claim 1, wherein the heating in step (b) is carried till exhaust of free starch completely and then cooled to 42 °C to 45 °C with adjusting the pH between 4.0 to 7.0.
8.T he process for preparation of hydroxyethyl starch as claimed in claim 1, wherein the organic solvent is selected from the group of iso-propyl alcohol,. methyl alcohol, ethyl alcohol, acetone, dimethyl sulfoxide and n-propyl alcohol preferably iso-propyl alcohol.
9.T he process for preparation of hydroxyethyl starch as claimed in claim 1, wherein the ultra filtration is carried with 1-50 KD cassettes to remove all compounds which are below 30,000 molecular weight and the ultra filtration is carried out until the chloride content is less then 0.5 %.
10. The process for preparation of hydroxyethyl starch as claimed in any of the preceding claims and as substantially described with reference to the foregoing example.