Field of the Invention:
The Invention provides micro encapsulated formulation of gymnemic acid enriched fraction and
method of preparation of said formulation. The invention also provides extraction method of obtaining
gymnemic acid/s enriched fraction from the herb Gymnema sylvestra.
Background of the Invention:
Plant based drugs and formulations are showing a rising trend globally for the health care due to the
biosafe attributes they possess over modern synthetic medicines. Amongst the numerous traditional
Indian medicinal herbs, standardized extract of Gymnema sylvestre R. Br. (Asclepiadaceae), finding
increasing use as a constituent of modern herbal nutraceuticals aimed at the treatment of diabetes
mellitus and in food additives against obesity and caries (Porchezhian & Dobriyal et al., 2003)
Gymnema sylvestre is a woody, climbing plant, native to India, Africa and China (Stoecklin et al.,
1969). It has been used in the treatment of diabetes, impaired glucose tolerance, and various conditions
associated with diabetes. It is commonly called as Gurmar, meaning ‘‘sugar destroying,’’ which is
suggestive of the distinctive property of temporarily destroying the taste of sweetness. Studies have
revealed that the water extract of the leaves of the plant inhibited absorption of glucose in the small
intestine and suppressed the increase of blood sugar value after administration of sucrose in rats
(Yoshioka et al., 1986; Pitchai et al., 2009)
Systematic Chemical Examination of Gymnema sylvestre has sown that gymnemic acids (GA), a
saponins with a triterpenoid structure contained in Gymnema sylvestre leaves have various
pharmacological effects. They suppress taste sensitivity to sweetness after oral
administration,(Diamant et al., 1965) inhibit intestinal glucose absorption,( Yoshioka et al., 1986) and
lower plasma glucose levels and insulin levels (Murakami et al.1996; Abe et al., 1993). Gymnemic
acids change glucose utilization patterns and enzyme activities in experimentally induced diabetic
animals, (Shanmugasundaram et al., 1983) inhibit glucose-stimulated gastric inhibitory peptide
secretion in rats (Fushiki et al., 1992). Gymnemic acids are complex pentacyclic triterpenic saponins
and regarded as anti-saccharine principle of G. sylvestre (Yoshikawaet al., 1991; Dateo and Long,
1973). Gymnemagenin, a common aglycone of gymnemic acids produced after acidic and basic
hydrolysis has been commonly used as an analytical marker to determine the quality of Gymnema
plant materials (Puratchimaniand Jha, 2004).
A method was developed for the isolation of gymnemic acids from Gymnema sylvestre without
undergoing hydrolysis by Hwang et al. 1991. The step includes the initial sterilization of leaves with
N2 gas at 1200C followed by extraction of leaves in the presence of phosphate buffer of pH 7 at 60OC.
Fat soluble ingredients are removed with an organic solvent lighter than water, such as hexane,
heptane, and petroleum ether and removal of chlorophyll was achieved with an organic solvent heavier
-3-
than water, such as chloroform, ethylene dichloride, and Carbon tetrachloride. Solutes content in the
extract can be increased from 10% to 15% by modifying the extraction process. However the use of N2
at large scale industrial unit is not economically feasible. This method apart from being very tedious
and time consuming, involves the use of potentially carcinogenic solvent like chloroform, ethylene
dichloride, and carbon tetrachloride. A chromatographic method is also found to be effective in the
isolation of gymnemic acids. Elution of an aqueous extract of Gymnema with ethanol in column
chromatography containing synthetic resin as adsorber, resulted in the separation of gymnemic acids.
But the extraction and isolation of compounds through column chromatography is a very time
consuming and tedious job (Yumoto et al., 1989).
Most of the patent literature also does not disclose any information on the subject of efficient
production technology of gymnemic acid. The literature contains a few lab scale methods for the
preparation of an extract of Gymnema sylvestre containing gymnemic acid. Therefore, there is a
highlighting need for an extraction process for obtaining gymnemic acid enriched fraction from
Gymnema sylvestre.
The US Patent 5,605,698 discloses various oral compositions incorporating gymnemic acid as a
dietary aid in the form of a chewable gum, chewable tablet, oral refrigerant or oral troche. The
procedure for the extraction of gymnemic acid consists of soaking the powdered plant material in 30%
alcohol solvent, and the resultant extract was dried and powdered. US Pat. No. 5,980,902 and US. Pat.
No. 5,900, 240 discloses the use of Gymnema sylvestre as a dietary supplement useful for lowering the
glucose level of the blood in those suffering from diabetes mellitus.
Similarly, US. Pat. No. 5,730,988 and US. Pat. No. 4,761,286 discloses the use of Gymnema sylvestre
to inhibit the absorption of glucose in the intestinal tract. Gymnema sylvestre has also been
incorporated into dietary supplements which are purported to reduce the build-up of body fat.
Gymnema sylvestre is an interesting source of gymnemic acid which can be used as bioactive
ingredients in antidiabetic drugs. However, it has been found that many of these factions or extracts
are unstable and that when stored for long periods, the active ingredients are often eliminated or
otherwise rendered inactive. In addition, some, if not all, of the gymnemic acid contained in these
fractions or extracts are quickly eliminated from the body. These molecules are unstable and has a
short shelf life. Also, the gymnema extracts are very astringent and bitter in taste that makes it difficult
to use as such. Thus, formulation of the gymnema extracts with desirable properties of having greater
stability, enhanced shelf life and an acceptable taste is highly needed.
-4-
Object(s) of the Invention:
An object of the present invention is to provide a microencapsulated formulation comprising
gymnemic acid enriched extract from Gymnema sylvestre for improving the shelf life and regulated
release of the product.
Yet another object of the present invention is to provide a method of preparing the microencapsulated
formulation based on gymnemic acid enriched extract from Gymnema sylvestre.
Yet another object of the present invention is to provide a simple, economic and efficient extraction
method for obtaining gymnemic acid enriched extract.
Another object of the present invention is to provide a simple, economic and efficient extraction
method for obtaining gymnemic acid enriched extract from Gymnema sylvestre.
Yet another object of the present invention is to provide a method which is less time consuming and
quick.
Summary of the Invention:
In an aspect of the Invention, there is provided a microencapsulated formulation of bioenriched extract
of gymnemic acid comprising bioenriched extract of gymnemic acid present in an amount ranging
from 5% to 30%, natural polymer present in an amount ranging from 5% to 30% and adjuvant present
in an amount ranging from 0.1% to 5%;
where said polymer is selected from a group comprising of food grade edible starch, soluble starch,
cellulose, dextrins, mannitol, cyclodextrins, maltodextrin, dextrin, microcrystalline cellulose or
combinations thereof;
where said adjuvant is selected from a group comprising of gum acacia, xanthum gum, guar gum,
pectin, gelatin or combinations thereof.
In another aspect of the Invention, there is provided a method of preparing microencapsulated
formulation of bioenriched extract of gymnemic acid, said method comprising steps of:
a) Combining said bioenriched extract of gymnemic acid in an amount ranging from 5% to
30% with a polymer present in an amount ranging from 5% to 30% and adjuvant present
in an amount ranging from 0.1% to 5% to obtain solution (A);
b) Sonicating Solution (A) for approximately 10 minutes followed by feeding said solution
in the spray drier at approximately 20ml per minute to obtain microencapsulated
formulation of bioenriched extract of gymnemic acid.
-5-
In another aspect of the Invention, there is provided a method of obtaining bioenriched extract of
gymnemic acid from Gymnema species, said method comprising steps of:
a) Extracting the starting material with aqueous alcohol solution atleast three times by
refluxing on the water bath for approximately 6 hrs at temperature of around
50 to 60OC;
b) Filtering the extract resulting from step (a) followed by concentrating on rotary vacuum
evaporator at temperature of around 40OC to remove any alcohol content;
c) Diluting the extract resulting from step (b) with water followed by partitioning the aqueous
layer with solvent (i) followed by solvent (ii) for removing fatty coextractive
along with intermediate polar compounds to obtain said bioenriched extract of
gymnemic acid.
Detailed Description:
The Invention provides micro encapsulated formulation of gymnemic acids enriched fraction and
method for the preparation of said formulation. The Invention also provides extraction method of
obtaining gymnemic acids enriched fraction from the herb Gymnema sylvestra.
The present Invention has been described considering Gymnema sylvestra as the preferred herb for
extracting gymnemic acids enriched fraction. However, the scope of present Invention cannot be
considered as restrictive and the explained extraction method and other embodiments shall be
applicable with other sources as well.
The Invention provides a microencapsulated formulation of bioenriched extract of gymnemic acid
comprising bioenriched extract of gymnemic acid present in an amount ranging from 5% to 30%,
natural polymer present in an amount ranging from 5% to 30% and adjuvant present in an amount
ranging from 0.1% to 5%. The polymer is selected from a group comprising of food grade edible
starch, soluble starch, cellulose, dextrins, mannitol, cyclodextrins, maltodextrin, dextrin,
microcrystalline cellulose or combinations thereof. The adjuvant is selected from a group comprising
of gum acacia, xanthum gum, guar gum, pectin, gelatin or combinations thereof.
In an embodiment, the microencapsulated formulation of bioenriched extract of gymnemic acid
comprises bioenriched extract of gymnemic acid (5 to 25 gm of crude extract and more preferably 20
gm), cassava starch (5 to 30 % and more preferably 20%) and gum acacia (0.1 to 5% and more
preferably 0.25%).
The microencapsulated formulation comprises Gymnema sylvestre extract rich in Gymnemic acid as
the active components.
-6-
In an embodiment, the encapsulated powder of gymnema leaf extract contains bio-enriched gymnemic
acid in native form whose conc. is in the range of 4.3% on dry basis.
The encapsulated powder of gymnema extract is a stable and possess better bio-availability.
In an important aspect of the Invention, there is provided a method of preparing microencapsulated
formulation of bioenriched extract of gymnemic acid, said method comprising steps of:
a) Combining said bioenriched extract of gymnemic acid in an amount ranging from 5% to 30%
with a polymer present in an amount ranging from 5% to 30% and adjuvant present in an
amount ranging from 0.1% to 5% to obtain solution (A);
b) Sonicating Solution (A) for approximately 10 minutes followed by feeding said solution in the
spray drier at approximately 20ml per minute to obtain microencapsulated formulation of
bioenriched extract of gymnemic acid.
In an embodiment, the spray drying is performed at inlet temperature of approximately 1200C, outlet
temperature of approximately 700C, flow rate of approximately 20ml/minute.
In an embodiment, the method of preparing microencapsulated formulation of bioenriched extract of
gymnemic acid comprises essential steps of:
a) preparing a solution of bioenriched extract of gymnemic acid and a natural polymer
comprising cassava starch and a adjuvant gum acacia, said bioenriched extract and cassava
starch present in a amount ranging from (5 to 30%) and gum acacia (0.1 to 5%) followed by
sonication for about 10 minutes to obtain homogenous slurry;
b) spray drying the slurry obtained in step (a) with customized inlet temperature of around 120°C,
outlet temperature of around 70°C, flow rate of around 20 ml/min to obtain said
microencapsulated formulation of bioenriched extract of gymnemic acid.
In an embodiment, the method essentially comprises steps of extracting bio-active gymnemic acid
from Gymnema sylvestre in native form and spray drying these extract with suitable matrix like
cassava starch and gum accaia to obtain encapsulated spray dried gymnemiac acid enriched powder
from Gymnema sylvestre. The method produces a stable product with longer shelf-life and greater bioavailability.
-7-
In another embodiment, there is provided a process for the preparation of encapsulated spray dried
gymnemiac acid enriched powder from Gymnema sylvestre, where the process comprises following
steps:
i) extracting the dried, powdered leaves of step with aqueous alcohol by refluxing for a period of
4 to 8 hrs with mixture of water and water miscible low molecular alcohol,
ii) filtering the solution of step (i) to provide aqueous alkanol extract and removing alcohol under
reduced pressure preferably under vacuum and at about 500C to provide essentially an
aqueous extract,
iii) defatting the aqueous extract of step (ii) by partitioning the aqueous extract with petroleum
ether and subsequent partitioning by ethyl acetate to remove intermediate co-extractive iv)
Separating the organic layer and aqueous layer and) aqueous extract free from fatty
materials and intermediate co-extractive was dilute in 2 to 10 parts of double distilled water
v) filtering the water extract of step
iv) through a whatman filter paper to obtain a water extract vi) mixing the water extract of step
v) with cassava starch and gum acacia solution, and spray drying the mixture of step to obtain
encapsulated spray dried gymnemiac acid enriched powder from Gymnema sylvestre.
In an embodiment, the spray drying of the water extract is performed maintaining an inlet temperature
in the range of 110 to 140°C; more preferably 120°C and an outlet temperature in the range of 65°C to
75°C more preferably 70°C and the feed rate of water extract is in the range of 10 ml to 40 ml per
minute and more preferably 20 ml per minute.
In an important aspect of the Invention, there is provided an efficient extraction method for the
preparation of gymnemic acid enriched fraction from the herb Gymnema sylvestre.
The method of obtaining bioenriched extract of gymnemic acid form Gymnema sylvestre comprising
following steps:
a) Extracting the starting material with aqueous alcohol solution atleast three times by
refluxing on the water bath for approximately 6 hrs at temperature of around
50 to 60OC;
b) Filtering the extract resulting from step (a) followed by concentrating on rotary vacuum
evaporator at temperature of around 40OC to remove any alcohol content;
-8-
c) Diluting the extract resulting from step (b) with water followed by partitioning the aqueous
layer with solvent (i) followed by solvent (ii) for removing fatty coextractive
along with intermediate polar compounds to obtain said bioenriched extract of
gymnemic acid
In an embodiment, the extraction method is technically advantageous as the method eliminates use of
any toxic solvent of column chromatograph method.
In an embodiment, the weight ratio of gymnema leaf meal and aqueous alcohol ranges between 1:1 to
1:10 and more preferably 1:5 and the ratio of alcohol to water ranges between 1 :1 and 9:1 and more
preferably 4:1
In an embodiment, the water miscible low molecular alcohol is selected from a group consisting of
methanol or ethanol, preferably methanol.
In an embodiment, the w/w ratio of the aqueous extract and petroleum ether and ethyl acetate is in the
range of 1:0.8 to 1:1.2 and more preferable 1:1.
In an embodiment, the yield of gymnemic acid from Gymnema sylvetre is in the range of 2.1-13.2%.
In another important aspect of the Invention, there is provided a microencapsulated formulation
comprising gymnemic acid enriched fraction and its method of preparation.
The below listed comparison shows higher yield and advantages of extraction method of present
Invention as compared to the conventional methods:
Method Yield % Comments Reference
Hot water extraction followed by
column chromatography and
gymnemic acid in the form of Na, K
or NH4 salt
0.1 to 0.5%
(w/w)/ 100 g of
the dried leaves
Tedious process
and gymnemic acid
obtained as a NA,
K or NH4 salt and
not in native form
Hiji, Y. (1990).
Cariostatic
materials and
foods, and method
for preventing
dental caries.
United States
Patent. US Patent
no. 4,912,089.
Refluxing by ethanol, filtering and
concentrating, centrifugation and
passing the supernatant in
macroporous adsorbing resin
column, concentrating the solution
Product
containing
gymnemic acid
glyocosides 4%
Tedious process Medicinal
composition for
auxiliary treatment
of diabetic
coronary artery
-9-
and finally vaccume drying.
disease
CN 102793798 A
Extraction with aqueous ethanol
followed by ultrafiltration then
filtrate is subjected to absorption by
anion exchange resin and
decolorization by using activated
carbon.
Product contain
gymnemic acid
85-92%
Very tedious
method and though
the conc. of
gymnemic acid in
final extract is high
but the yield from
the starting
materials (dry
leaves) is very low
Method for
extracting
gymnemic acid
from
gymnema sylvestre
CN 102911244 A
A method was developed for the
isolation of gymnemic acids from
Gymnema sylvestre without
undergoing hydrolysis by Hwang et
al. 1991. The step includes the initial
sterilization of leaves with N2 gas at
120 OC followed by extraction of
leaves in the presence of phosphate
buffer of pH 7 at 60 OC. Fat soluble
ingredients are removed with an
organic solvent lighter than water,
such as hexane, heptane, and
petroleum ether and removal of
chlorophyll was achieved with an
organic solvent heavier than water,
such as chloroform, ethylene
dichloride, and Carbon tetrachloride.
Product contain
gymnemic acid
upto $%
This method apart
from being very
tedious and time
consuming,
involves the use of
potentially
carcinogenic
solvent like
chloroform,
ethylene
dichloride, and
carbon
tetrachloride
Hwang BY, Choi
SY (1991)
EP0406516A1 A
process for
extracting the
concentrated
gymnemate from
gymnema sylvestre
and an equipment
for using in the
process
Extraction of gymnemic acid from
Gymnema sylvestre by aqueous
alcohol extraction, solvent - solvent
partition, and converting the native
acid into a microencapsulated form.
Max yield upto
13.1% per dry
extract basis and
4.3% in
microencapsulated
product
Simple method and
formulation of
gymnemic acid in
native form
Present study
In another aspect of the Invention, there is provided a method of preparing the microencapsulated
formulation. The method particularly involves spray drying technology with cassava starch as a wall
material. The Gymnemic acid in its native form from Gymnema sylvestre was extracted using the
above defined extraction process.
The Invention is further described with the help of non-limiting examples:
Example 1
Extraction and enrichment of bioactive gymnemic acid from Gymnema sylvetsre
-10-
100 gm of dried powdered leaves of Gymnema sylvestre leaves was extracted thrice with 500 mL of
ethyl acetate by refluxing on the water bath for 6 hrs at temperature of 50-60 OC. The extract was
filtered and concentrated on rotary vacuum evaporator at 40OC to yield gymnemic acid enriched crude
extract. Gymnemagenin a com-mon aglycone of gymnemic acids produced after acidic and basic
hydrolysis has been commonly used as an analytical marker to determine the quality of Gymnema
plant materials (Puratchimaniand Jha, 2004). The gymnemic acid content in the extract was estimated
in terms of gymnemagenin content using HPLC method.
 Weight of gymnemic acid enriched crude concentrate: 19.6
 Gymnemic acid content: 2.1% (per gram of dry extract basis)
Example 2
100 gm of dried powdered leaves of Gymnema sylvestre leaves was extracted thrice with 500 mL of
methanol by refluxing on the water bath for 6 hrs at temperature of 50-60 OC. The extract was filtered
and concentrated on rotary vacuum evaporator at 40OC to yield gymnemic acid enriched crude extract.
Gymnemagenin a com-mon aglycone of gymnemic acids produced after acidic and basic hydrolysis
has been commonly used as an analytical marker to determine the quality of Gymnema plant materials
(Puratchimaniand Jha, 2004). The gymnemic acid content in the extract was estimated in terms of
gymnemagenin content using HPLC method.
Weight of gymnemic acid enriched crude concentrate: 23.5 gm
Gymnemic acid content: 4.3 % (per gram of dry extract basis)
Example 3
100 gm of dried powdered leaves of Gymnema sylvestre leaves was extracted thrice with 500 mL of
aqueous methanol (80% methanol) by refluxing on the water bath for 6 hrs at temperature of 50-60
OC. The extract was filtered and concentrated on rotary vacuum evaporator at 40OC to remove the
methanol. The remaining water extract was diluted with water to develop a solution of 100 mL. From
this 1 mL solution was taken and concentrated to determine the gymnemic acid content as well as the
yield of crude extract. Gymnemagenin a common aglycone of gymnemic acids produced after acidic
and basic hydrolysis has been commonly used as an analytical marker to determine the quality of
Gymnema plant materials (Puratchimaniand Jha, 2004). The gymnemic acid content in the extract was
estimated in terms of gymnemagenin content using HPLC method.
 Weight of gymnemic acid enriched crude concentrate: 30.2 gm
 Gymnemic acid content: 7.1 % (per gram of dry extract basis)
-11-
Example 4
100 gm of dried powdered leaves of Gymnema sylvestre leaves was extracted thrice with 500 mL of
aqueous methanol (80% methanol) by refluxing on the water bath for 6 hrs at temperature of 50-60
OC. The extract was filtered and concentrated on rotary vacuum evaporator at 40OC to remove the
methanol. The extrct was then dissolved in water to make a solution of 100 mL. The aqueous layer
was partinioed with petroleum ether followed by ethyl acetate to remove fatty co-extractive and
intermediate polar compounds. From the partinoied aqueous layer, 1 mL solution was taken and
concentrated to determine the gymnemic acid content as well as the yield of crude extract.
Gymnemagenin a common aglycone of gymnemic acids produced after acidic and basic hydrolysis
has been commonly used as an analytical marker to determine the quality of Gymnema plant materials
(Puratchimaniand Jha, 2004). The gymnemic acid content in the extract was estimated in terms of
gymnemagenin content using HPLC method.
 Weight of gymnemic acid enriched crude concentrate:22.3
 Gymnemic acid content: 13.2 % (per gram of dry extract basis)
Example 5:
Preparation of spray dried encapsulation of bio-enriched gymnemic acid from Gymnema
sylvestre
Bio-enriched extract obtained by extraction of leaves of gymnema sylvestre from the proceduere of
example 4 was used for preparation of spray dried microencapsulation. For this 100 gm of dried
powdered leaves of Gymnema sylvestre was extracted thrice with 500 mL of aqueous methanol (80%
methanol) by refluxing on the water bath for 6 hrs at temperature of 50-60 OC. The extract was filtered
and concentrated on rotary vacuum evaporator at 40OC to remove the methanol. The extract was then
dissolved in water to make a solution of 100 mL. The aqueous layer was partitioned with petroleum
ether followed by ethyl acetate to remove fatty co-extractive and intermediate polar compounds. The
remaining water extract was again dissolve in distilled water to make 100 mL of solution. 20% of
cassava starch solution (20 g cassava starch in 100 mL of distilled water) containing 0.5 g of gum
acacia and was mixed until fully dissolved. The two mixtures were then then sonicated for 10 minutes
to make homogenous slurry. The solution is spray dried in cocurrent spray drier (Bowen Engg. Inc.
New Jersey, USA) capacity of (15L / hr) at inlet temperature 120°C, out let temperature 70°C with a
flow rate of 20 ml/min and obtained 23.1g of spray dried gymnemic acid powder with 4.3%
gymnemic acid concentration.
-12-
Advantages of Invention:
a) It has been observed that the gymnemic acid containing extract obtained from Gymnema
sylvestre has a highly hygroscopic nature and it is very difficult to dry which makes its further
formulation extremely difficult and inaccurate. The prior art process reported by Hiji (US
Patent no. 4,912,089) have utilized lypholisation for drying the Gymnema sylvestre extract for
using in their experimental studies. Lypholisation as a drying technique is time consuming and
requires generation of very low temperature and high vacuum of the order of which has to be
achieved with capital intensive equipment and energy intensive operation. The improved
process of this invention makes use of spray drying of stabilized extract, as a speedier low cost
alternative to obtain the final product as a non-hygroscopic and free flowing powder with
uniform particle size.
b) The improved extraction process achieves the production of gymnemic acid rich extract from
Gymnema sylvestre by using relatively non toxic solvents like petroleum ether, ethyl acetate
and methanol, unlike the prior art process which requires the use of toxic and potentially
carcinogenic solvent like chloroform, ethylene dichloride and tedious process like column
chromatography method. The positive effect of the invention is the room temperature
extraction, low energy consumption.
a) The stabilization of the gymnemic acid containing extract is achieved in the improved process
by the judicious use of food grade non-toxic stabilizing agents such as natural polymer like
edible starch (cassava), mannitol, maltodextrin, dextrin, microcrystalline cellulose in an
amount ranging from 5-30%, and other adjuvants selected from a group comprising of gum
acacia, xanthum gum, guar gum, pectin, gelatin etc. present in an amount ranging from 0.1 to
5.0%. The stabilization of the gymnemic acid containing extract of Gymnema sylvestre has not
been reported so far.
b) The prior art process results in an extract which has an unpleasant bitter taste. It also has a dark
green colour. Since the Gymnema sylvestre extract is to be used for formulating nutraceuticals
& health foods, a palatable taste and lighter shade of the extract is of paramount importance for
achieving a final formulation having a pleasant taste and aesthetic appearance. The process of
this invention is able to remove the bitter taste components by converting it into an
encapsulated product. The resulting product purity, high degree of industrialization of
production

We Claim:
1. A microencapsulated formulation of bioenriched extract of gymnemic acid comprising
bioenriched extract of gymnemic acid present in an amount ranging from 5% to 30%, natural
polymer present in an amount ranging from 5% to 30% and adjuvant present in an amount
ranging from 0.1% to 5%;
where said polymer is selected from a group comprising of food grade edible starch, soluble
starch, cellulose, dextrins, mannitol, cyclodextrins, maltodextrin, dextrin, microcrystalline
cellulose or combinations thereof;
where said adjuvant is selected from a group comprising of gum acacia, xanthum gum, guar
gum, pectin, gelatin or combinations thereof.
2. A method of preparing microencapsulated formulation of bioenriched extract of gymnemic acid,
said method comprising steps of:
c) Combining said bioenriched extract of gymnemic acid in an amount ranging from 5% to
30% with a polymer present in an amount ranging from 5% to 30% and adjuvant present
in an amount ranging from 0.1% to 5% to obtain solution (A);
d) Sonicating Solution (A) for approximately 10 minutes followed by feeding said solution
in the spray drier at approximately 20ml per minute to obtain microencapsulated
formulation of bioenriched extract of gymnemic acid.
3. The method as claimed in claim 2, wherein said spray drying is performed at inlet temperature of
approximately 1200C, outlet temperature of approximately 700C, flow rate of approximately
20ml/minute.
4. A method of obtaining bioenriched extract of gymnemic acid from Gymnema species, said
method comprising steps of:
d) Extracting the starting material with aqueous alcohol solution atleast three times by
refluxing on the water bath for approximately 6 hrs at temperature of around
50 to 60OC;
e) Filtering the extract resulting from step (a) followed by concentrating on rotary vacuum
evaporator at temperature of around 40OC to remove any alcohol content;
f) Diluting the extract resulting from step (b) with water followed by partitioning the aqueous
layer with solvent (i) followed by solvent (ii) for removing fatty coextractive
along with intermediate polar compounds to obtain said bioenriched extract of
gymnemic acid.
-14-
5. The method as claimed in claim 4, wherein said starting material comprises shade dried herbage
of Gymnema sylvestre.
6. The method as claimed in claim 4, wherein said aqueous alcohol is selected from a group of low
molecular alcohol comprising aqueous methanol, alkanol, ethanol, isopropanol, butanol or
combinations thereof.
7. The method as claimed in claim 4, wherein said solvent (i) is selected from petroleum ether,
hexane, cyclohexene, heptane, petroleum ether or combinations thereof.
8. The method as claimed in claim 4, wherein said solvent (ii) is selected from ethyl acetate, ethyl
propionate, ethyl formate or combinations thereof.
9. The method as claimed in claim 4, wherein said starting material and aqueous alcohol is mixed in
a weight ratio ranging from 1:1 to 1:10.
The method as claimed in claim 4, wherein said bioenriched extract of gymnemic acid and solution (i)
and solution (ii) is combined in the weight ratio ranging from 1:0.8 to 1:1.2.