Claims:We Claim:
1. A nutritional composition comprising silica and an active agent selected from vitamin(s), mineral(s) and combination of mineral(s) and vitamin(s), the silica and the active agent forming a complex, wherein amount of the active agent released from the nutritional composition in intestinal fluid is at least 1.5 times than that released in gastric fluid.
2. A nutritional composition as claimed in claim 1, wherein the active agent is at least 8% (w/w) of the nutritional composition.
3. A nutritional composition as claimed in claim 1, wherein the silica and the active agent are in a weight ratio range of 3:1 to 11:1.
4. A nutritional composition as claimed in claim 1, wherein the mineral is selected from iron and calcium.
5. A nutritional composition as claimed in claim 1, wherein the vitamin is selected from vitamin B, vitamin C, vitamin D, vitamin E and vitamin A.
6. A nutritional composition as claimed in claim 1, wherein the silica is food grade mesoporous silica.
7. A method of preparing a nutritional composition comprising:
preparing a precursor solution of an active agent selected from vitamin(s), mineral(s) and combination of mineral(s) and vitamin(s);
adding food grade silica to the precursor solution to facilitate formation of a complex of silica and the active agent;
separating and drying the complex formed in the previous step, such complex being suitable for use as a nutritional composition which releases the active agent in intestinal fluid in an amount at least 1.5 times than that released in gastric fluid.
8. A method of preparing a nutritional composition as claimed in claim 7, wherein the mineral is selected from iron and calcium.
9. A method of preparing a nutritional composition as claimed in claim 7, wherein the vitamin is selected from vitamin B, vitamin C, vitamin D, vitamin E and vitamin A.
10. A method of preparing a nutritional composition as claimed in claim 7, wherein the precursor solution is an aqueous solution or an alcoholic solution depending on the active agent.
11. A method of preparing a nutritional composition comprising:
preparing a solution of an acid and gelatin;
preparing a mixture of sodium silicate and an active agent selected from vitamin(s), mineral(s) and combination of mineral(s) and vitamin(s);
adding the mixture to the solution to facilitate formation of a complex of silica and the active agent;
separating and drying the complex formed in the previous step, such complex being suitable for use as a nutritional composition which releases the active agent in intestinal fluid in an amount at least 1.5 times than that released in gastric fluid.
12. A method of preparing a nutritional composition as claimed in claim 11, wherein the mineral is selected from iron and calcium.
13. A method of preparing a nutritional composition as claimed in claim 11, wherein the vitamin is selected from vitamin B, folic acid and combination thereof.
14. A method of preparing a nutritional composition as claimed in claim 11, wherein the acid is selected from sulphuric acid, hydrochloric acid and ortho-phosphoric acid.
15. A method of preparing a nutritional composition as claimed in claim 11, wherein the sodium silicate and the active agent are mixed in a weight ratio range of 3:1 to 11:1.
Dated this 15th day of October, 2015

Aparna Kareer
Of Obhan & Associates
Agent for the Applicant
Patent Agent No. 1359 , Description:Present disclosure provides a nutritional composition for humans. The nutritional composition comprises silica and an active agent. The disclosure also provides a method(s) of preparation of such nutritional composition.

BACKGROUND
It is well known that vitamins and minerals are essential for many metabolic processes in humans. A deficiency of the same can lead to long term health problems. They cannot be synthesized by the human body and must be taken from external sources such as food and nutritional compositions. In general, vitamins and minerals are not stable in such nutritional compositions. Specifically, stability of vitamins and minerals during processing, transport and storage of the nutritional composition is a concern.
Though nutrients are available in natural food sources but still there is a huge percentage of population suffering from their deficiency. A number of supplements are available in the market but these are mainly pharmaceutical supplements, like Vitamin A, D supplemented tablets, etc. To increase the bioavailability of the vitamins in these supplements they are prepared by expensive formulations like micro encapsulations. There are many additives added to them to stabilize the molecules and enhance their delivery. These additives do not have any biological importance and the body needs to spend extra energy in their excretion. Further, people are usually reluctant to consume these tablets.
There is a need for a nutritional composition which is stable and inexpensive. Further, it is desirable that such nutritional compositions facilitate controlled release in human body. Also, there is a need for a method of preparation of such nutritional composition.

BRIEF DESCRIPTION OF DRAWINGS
Figure 1 illustrates release profile of vitamin E (loaded on silica) in simulated gastric and intestinal fluid in accordance with an embodiment of the present invention.
Figure 2 illustrates release profile of folic acid loaded on silica in simulated gastric and intestinal fluid in accordance with an embodiment of the present invention.
Figure 3 illustrates release profile of vitamin D (loaded on silica) in simulated gastric and intestinal fluid in accordance with an embodiment of the present invention.
Figure 4 illustrates the release profile of iron from silica in simulated gastro-intestinal fluid in accordance with an embodiment of the present invention.
Figure 5 illustrates the release profile of calcium from silica in simulated gastro-intestinal fluid in accordance with an embodiment of the present invention.

SUMMARY
The present disclosure provides a nutritional composition comprising silica and an active agent selected from vitamin(s), mineral(s) and combination of mineral(s) and vitamin(s), the silica and the active agent forming a complex, wherein amount of the active agent released from the nutritional composition in intestinal fluid is at least 1.5 times than that released in gastric fluid.
The present disclosure also provides a method of preparing a nutritional composition comprising preparing a precursor solution of an active agent selected from vitamin(s), mineral(s) and combination of mineral(s) and vitamin(s); adding food grade silica to the precursor solution to facilitate formation of a complex of silica and the active agent; separating and drying the complex formed in the previous step, such complex being suitable for use as a nutritional composition which releases the active agent in intestinal fluid in an amount at least 1.5 times than that released in gastric fluid.
The present disclosure also provides an alternate method of preparing a nutritional composition comprising preparing a solution of an acid and gelatin; preparing a mixture of sodium silicate and an active agent selected from vitamin(s), mineral(s) and combination of mineral(s) and vitamin(s); adding the mixture to the solution to facilitate formation of a complex of silica and the active agent; separating and drying the complex formed in the previous step, such complex being suitable for use as a nutritional composition which releases the active agent in intestinal fluid in an amount at least 1.5 times than that released in gastric fluid.

DETAILED DESCRIPTION
For the purpose of promoting an understanding of the principles of the invention, reference will now be made to embodiments and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the disclosed process and system, and such further applications of the principles of the invention therein being contemplated as would normally occur to one skilled in the art to which the invention relates.
It will be understood by those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the invention and are not intended to be restrictive thereof.
Reference throughout this specification to “one embodiment” “an embodiment” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrase “in one embodiment”, “in an embodiment” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.
Reference throughout this specification to “the center” means a portion located at and/ or proximate the center. Similarly, reference throughout this specification to “the first end” and “the second end” means a portion located at and/ or proximate the first end and a second end respectively.
The present disclosure provides a nutritional composition comprising silica and an active agent, the silica and the active agent forming a complex, wherein amount of the active agent released from the nutritional composition in intestinal fluid is at least 1.5 times than that released in gastric fluid.
In accordance with an aspect, silica and the active agent form a chemical complex thereby providing stability to the nutritional composition, as substantiated by zeta potential analysis (example 1 disclosed herein). Such complex formation provides improved shelf life to the nutritional composition as compared to conventional compositions which deteriorates in natural environment due to light and/or oxidation.
In accordance with an aspect, the active agent is selected from vitamin(s), mineral(s) and combination of mineral(s) and vitamin(s). Vitamin is selected from vitamin B, vitamin C, vitamin D, vitamin E, vitamin A and combination thereof. Mineral is selected from iron, calcium and combination thereof.
In accordance with an embodiment, when the active agent is vitamin(s), the amount of the active agent released from the nutritional composition in intestinal fluid is at least 2.5 times than that released in gastric fluid.
In accordance with an embodiment, the active agent is 8 to 21% (w/w) of the nutritional composition. In other words, the nutritional composition shows 8-21% (w/w) loading of active agent on silica
In accordance with an embodiment, the silica and the active agent are in a weight ratio in the range of 3:1 to 11:1.
In accordance with an embodiment, silica is food grade mesoporous silica.
In accordance with an embodiment, release of the active agent is analyzed in simulated intestinal fluid and simulated gastric fluid (as disclosed in examples).
The present disclosure also provides a method of preparation of above disclosed nutritional composition. The method comprising preparing a precursor solution of an active agent selected from vitamin(s), mineral(s) and combination of mineral(s) and vitamin(s); adding food grade silica to the precursor solution to facilitate formation of a complex of silica and the active agent. The method further comprising separating and drying the complex formed in the previous step, such complex being suitable for use as a nutritional composition which releases the active agent in intestinal fluid in an amount of at least 1.5 times than that released in gastric fluid. In this method silica is ex-situ synthesized silica.
In accordance with an embodiment, vitamin is selected from vitamin B, vitamin C, vitamin D, vitamin E, vitamin A and combination thereof.
In accordance with an embodiment, when the active agent is vitamin(s), the amount of the active agent released from the nutritional composition in intestinal fluid is at least 2.5 times than that released in gastric fluid.
In accordance with an embodiment, mineral is selected from iron, calcium and combination thereof.
In accordance with an embodiment, the precursor solution of the active agent is prepared by dissolving the active agent in an alcohol or water depending on the active agent. By way of an example, vitamin dissolved in ethanol to obtain precursor solution of vitamin. By way of an alternate example, vitamin is dissolved in aqueous solution of sodium hydrogen carbonate to obtain precursor solution of vitamin.
In accordance with an embodiment, silica is food grade mesoporous silica. Silica is highly porous and has high surface area which facilitates high percentage loading of the active agent thereon. Silica synergistically acts as a carrier for delivery of active agent in humans; and also acts as a nutrition source for humans.
In accordance with an embodiment, mixture obtained after adding food grade silica to the precursor solution is stirred for a time period in a range of 12-24 hours to facilitate complex formation of silica and the active agent.
In accordance with an embodiment, separation of the complex of silica and the active agent is carried out by centrifugation or filtration.
In accordance with an embodiment, centrifugation is carried out at a speed of 4000 rpm for 5 minutes.
In accordance with an alternate embodiment, centrifugation is carried out twice at a speed of 4000 rpm for 5 minutes.
In accordance with an embodiment, subsequent to the separation, the complex of silica and the active agent is dried and ground. By way of example, subsequent to the centrifugation, supernatant is discarded and thus obtained precipitate is dried and ground.
In accordance with an embodiment, drying can be carried out in a dessicator or under vaccum. By way of an example, drying is carried out in a desiccator for 24 hrs to obtain dried complex of silica and the active agent suitable for use as a nutritional composition. Quantification studies of the nutritional composition shows 8-21% (w/w) loading of vitamins on silica.
In accordance with an embodiment, the active agent is 8 to 21% (w/w) of the nutritional composition.
The present disclosure also provides an alternate method of preparing a nutritional composition. The method comprising preparing a solution of an acid and gelatin; preparing a mixture of sodium silicate and an active agent selected from vitamin(s), mineral(s) and combination of mineral(s) and vitamin(s); adding the mixture to the solution to facilitate formation of a complex of silica and the active agent. The method further comprising separating and drying the complex formed in the previous step, such complex being suitable for use as a nutritional composition which releases the active agent in intestinal fluid in an amount of at least 1.5 times than that released in gastric fluid. In this method silica is in-situ synthesized silica.
In accordance with an embodiment, vitamin is selected from vitamin B, folic acid and combination thereof.
In accordance with an embodiment, when the active agent is vitamin(s), the amount of the active agent released from the nutritional composition in intestinal fluid is at least 2.5 times than that released in gastric fluid.
In accordance with an embodiment, mineral is selected from iron, calcium and combination thereof.
In accordance with an embodiment, acid is selected from sulphuric acid, hydrochloric acid and orthophosphoric acid.
In accordance with an embodiment, sodium silicate and the active agent are mixed in a weight ratio range of 3:1 to 11:1.
In accordance with an embodiment, the sodium silicate used can either be synthesized by boiling rice husk ash in an aqueous solution of sodium hydroxide or commercially available sodium silicate solution.
In accordance with an embodiment, the mixture of sodium silicate and the active agent is added drop wise to the solution of acid and gelatin till neutralization. Such addition facilitates formation of complex of silica (synthesized in-situ) and the active agent.
In accordance with an embodiment, separation of the complex of silica and the active agent is carried out by centrifugation or filtration.
In accordance with an embodiment, centrifugation is carried out at a speed of 4000 rpm for 5 minutes.
In accordance with an alternate embodiment, centrifugation is carried out twice at a speed of 4000 rpm for 5 minutes.
In accordance with an embodiment, subsequent to the separation, the complex of silica and the active agent is dried and ground. By way of example, subsequent to the centrifugation, supernatant is discarded and thus obtained precipitate is dried and ground.
In accordance with an embodiment, drying is carried out in a desiccator for 24 hrs to obtain dried complex of silica and the active agent suitable for use as a nutritional composition. In accordance with an alternate embodiment, drying is carried out at a temperature of 30oC under vaccum. Quantification studies of the nutritional composition shows 8-21% (w/w) loading of vitamins on silica.
In accordance with an embodiment, the active agent is 8 to 21% (w/w) of the nutritional composition.
The following example(s) of method for preparing a nutritional composition for plants are exemplary and should not be understood to be in any way limiting.
Example 1
Zeta Potential Measurements
Zeta potential is an important property of the particle in dispersion as it exerts a significant influence on their stability based on surface charge. The results of zeta potential for silica particles without and with different nutrients are shown in Table below (Table 1). Zeta potential was reported as the average and standard deviation of measurements, with five reading taken per sample. The table below indicates that zeta potential of silica particles after nutrient loading is significantly changed. This change is clearly due to the attachment of the vitamins/ minerals.
Table 1
Sample Zeta Potential
Silica (-) 38.8 ± 0.1
Folic acid + Silica (-) 49.5 ± 0.1
Vitamin A + Silica (-) 45.2 ±0.3
Iron + Silica (-) 24 ± 0.1
Calcium + Silica (-) 14.9 ± 0.1

The above table indicates that there is change in the surface charge distribution of nutrient loaded silica when compared with their respective bare silica. Folic acid and Vitamin A are negatively charged particles so it developed a net increase in charge on the surface of silica. It affects the ion distribution and increases the charge of silica loaded with folic acid and vitamin A. Both iron and calcium are divalent cations so it affects the charge distribution of silica. The sample calcium loaded silica shows reduction in the charge as calcium itself is positively charged and the same stabilizes with negatively charged silica.
Though structural features of the loaded silica does not show any visible change before and after loading however, FTIR and Zeta potential results show distinct changes. This clearly indicates that the silica particles retain their structural functionality even after loading and there is surface interaction between the silica and vitamins. The stability of vitamins loaded silica results show that natural vitamins which are easily destroyed in natural environment due to light or oxidation, are found to be stable up to 60 days even after storage at room temperature. These samples were then subjected to various simulated environments to test for their release from silica matrix. The release profile studies were carried out in simulated gastric and intestinal environments. All the vitamins showed negligible release in the simulated gastric juice whereas considerable amount was released in the intestinal simulated fluids. This characteristic is an important feature as all these vitamins are known to be absorbed in the intestinal region of the human gastro-intestinal tract.
Example 2
Estimation of nutrients loaded onto silica matrix using ICP MS and HPLC
Table 2:
Sample Loading percentage
Vitamin D 8.3%
Vitamin E 21.38%
Folic acid 10.6%
Iron 21%
Calcium 10%

Example 3
Ex-situ loading of the Vitamin E: 6.39 g of Vitamin E was dissolved in 100 ml of absolute ethanol. To this homogenous solution 10 g of commercial food grade Silica was added slowly with continuous stirring. The mixture was kept in a rotatory shaker for overnight stirring at 120 rpm. The samples were then centrifuged at 4000 rpm for 5 min and supernatant was collected for analysis. The solids which settled down were washed again with ethanol to remove any unbound Vitamin E by centrifuging at 4000 rpm for 5 min. Again the supernatant was collected for analysis and the powder is dried in a dessicator for 24 hr. Once the samples were dried they were ground and used for further analysis by particle size analyzer, Fourier Transfer Infrared Spectroscopy, UV- Spectroscopy, Thermo gravimetric analysis, BET surface area and HPLC. 0.1 mg of samples were taken and dissolved in absolute ethanol. This dispersed sample was used to measure the particle size and the zeta potential of the silica before and after loading of the vitamin. IR spectra of the samples were recorded in the range of 400 – 4000 cm 1. The UV- Vis absorbance of the supernatant collected was measured using a UV- Vis Spectrometer and the amount of Vitamin present was calculated by plotting against a suitable standard. High Performance Liquid Chromatography in a mobile phase used for quantification of vitamin loaded onto silica particles. Quantification studies resulted in 20% loading of vitamin E onto silica particles.
Example 4
Ex-situ loading of Vitamin D: 5 g of vitamin D was dissolved in a conical flask containing 100 ml of absolute ethanol. To this homogenous solution, 10 g of silica powder was added slowly with continuous stirring. The mixture was kept in a rotatory shaker for overnight stirring at 120 rpm. The sample was then centrifuged at 4000 rpm for five min and supernatant is collected for analysis. The powder which settled down was washed again with ethanol to remove any unbound vitamin D by centrifuging at 4000 rpm for five min. Again the supernatant was collected for analysis and the powder is dried at 40 ºC under vacuum. Once the sample was dried and crushed using a mortar and pestle, it was further characterized. Quantification studies resulted in 7 to 8% loading of vitamin D3 onto silica particles.
Example 5
In-vitro sustained-released studies of fat soluble vitamins: The in vitro release profile of the vitamins D & E loaded onto silica were determined by gastric and intestinal release processes. Samples were subjected to simulated environments of the gastro-intestinal tract by preparation of simulated fluids, maintenance of pH and temperature and time estimation.
Release in gastric conditions: Accurately weighed 0.1 mg nutrient loaded silica was transferred to a beaker containing 15 ml of simulated gastric fluid. The simulated gastric fluid was prepared by dissolving 2 g of sodium chloride in 100 ml of distilled water. 7 ml of concentrated hydrochloric acid was added drop wise. 3.2 g of pepsin was added to the solution and the volume was made up to 1000 ml and checked for pH. The gastric fluid is acidic so the pH was maintained between 1 - 1.3. The test solution has a pH of about 1.3. Initially the mixture was mixed slightly and placed in a shaker incubator rotating at 50 rpm and maintained at 37°C. The supernatant has been removed at a time interval of 30 min for next 2 hr. The supernatant was filtered through 0.45 µm Millipore membrane filter and then was analyzed for the amount of vitamin present by HPLC method.
Release in intestinal conditions: For intestinal release study the pH of the solution obtained after gastric digestion was adjusted to neutral by addition of simulated intestinal fluids and the above gastric fluid treated sample was added to it after filtration through 0.45 µm Millipore membrane. The intestinal simulated fluid was prepared by dissolving 6.8 g of monobasic potassium phosphate in 250 ml of water, mixed properly and 77 ml of 0.2 N sodium hydroxide and 500 ml of water were added. 10 g of pancreatin was added. Mixture was mixed thoroughly and pH was adjusted to 6.8 with either 0.2 N sodium hydroxide or 0.2 N hydrochloric acid. The volume was made up to 1000 ml with distilled water. The bottles were again placed in shaker incubator rotating at 50 rpm and maintained at 37°C. The supernatant was removed at a time interval of 30 min for next 2 hr. The supernatant was filtered through 0.45 µm Millipore membrane filter and then was analyzed for the amount of vitamin present by HPLC method. Figure 1 and 3 illustrates release profile of vitamin E and D (loaded on silica) in simulated gastric and intestinal fluid.
Example 6
Ex-situ loading of folic acid: Folic acid (2 g) was dissolved in aqueous solution of 6% sodium hydrogen carbonate and to this homogenous solution 10 g of commercial food grade silica was added while stirring. The mixture was kept in rotatory shaker for overnight stirring at 120 rpm. The samples were then centrifuged at 4000 rpm for 5 min and supernatant was collected for analysis. The solids which settled down were dried under vacuum at 30 °C. Once the samples were dried, they were ground and used for further analysis by particle size analyzer, Fourier Transfer Infrared Spectroscopy, UV- Spectroscopy, Thermo gravimetric analysis, BET surface area and HPLC. 0.1 mg of sample was taken and dissolved in water. This dispersed sample was used to measure the particle size and the zeta potential of the Silica before and after loading of the folic acid. IR spectra of the samples were recorded in the range of 400 – 4000 cm 1. The UV- Vis absorbance of the supernatant collected was measured using UV- Vis Spectrometer and the amount of folate present was calculated by plotting against a suitable standard. High Performance Liquid Chromatography in a mobile phase used for quantification of folates loaded onto silica particles. Quantification studies resulted in 19% loading of folates onto silica particles.
Example 7
In-situ loading of folic acid: 2g of folic acid was added to 100 ml of 14 % commercial grade sodium silicate and stirred for 5 min. In 100 ml of 2.5 M of sulfuric acid, 2% of gelatin was dissolved and stirred for 10 minutes. Thereafter, 54 ml of folic acid dissolved in sodium silicate solution was added drop wise to sulfuric acid-gelatin solution until neutralization (pH ~ 6.5-7). The samples obtained were centrifuged at 4000 rpm for 5 min and was dried under vaccum at 30 °C. Once the samples were dried it was ground and used for further analysis.
In another reaction, 2g of folic acid was added to 100 ml of sodium silicate extracted from rice husk ash and stirred for 5 min. In 100 ml of 2.5 M of sulfuric acid, 2% of gelatin was dissolved and stirred for 10 minutes. Thereafter, 68 ml of folic acid dissolved in sodium silicate solution was added drop wise to sulfuric acid-gelatin solution until neutralization (pH ~ 6.5-7). The samples obtained were centrifuged at 4000 rpm for 5 min and was dried under vaccum at 30 °C. Once the samples dried it was grinded and used for further analysis. Quantification studies resulted in ~18 % loading of folates onto silica particles.
The samples were analysed by particle size analyser, Fourier Transfer Infrared Spectroscopy, UV- Spectroscopy, Thermo gravimetric analysis, BET surface area and HPLC.
Example 8
In-situ loading of iron and Vitamin C: Ferrous sulfate was used as precursor for loading of Iron. To 100 ml of 1.5M sulfuric acid 2% gelatine was dissolved and stirred for 10 minutes. 20 g of ferrous sulfate was added to the above solution. Ascorbic acid was used as capping agent for iron to maintain it in its ferrous state. It was taken in a ratio of ferrous sulfate (1): ascorbic acid (0.5). The reaction mixture was left for stirring. Sodium Silicate solution was added drop wise and checked for neutralization (pH=6.5-7). The samples were centrifuged at 4000 rpm for 5 minutes and were dried under hot air oven. The samples were dried and grinded into fine powder. The powder generated was analyzed by different characterization technique. 68 ml sodium silicate was consumed in the reaction. . In such nutritional composition, ascorbic acid also acts as stabilizing agent for iron.
In vitro sustained-released studies of water soluble vitamins
The in-vitro study was conducted to quantify the amount of folic acid and Iron leached out from the matrix in the fluid during the gastric and intestinal digestion. The recommended amount of folic acid and iron was added to the fluid. The release amount of folic acid was measured by high performance liquid chromatography (HPLC) and iron by inductively coupled plasma spectroscopy.
Gastric Digestion: Gastric fluid was prepared to conduct the digestion process. 2 g of sodium chloride was added to 100 ml of water. 7 ml of concentrated hydrochloric acid was added drop wise. 3.2 g of Pepsin was added to the solution and the volume is made up to 1000 ml and checked for pH. The gastric fluid is acidic so the pH was maintained around 1 to 1.3. Pepsin was added prior to the acidification of the samples to pH 2 to pH 4. Acidification of the samples to pH 2 or 4 is important, because pepsin begins to denature itself and thus will lose its activity at pH =5.
Digestion process: The procedure used for in-vitro gastric digestion. Weighed amount of samples was added in 50 ml of gastric juices. The mixture was stirred for 2 minutes. The beaker was placed in a shaker incubator at 50 rpm. The temperature of shaker incubator was maintained at room temperature 37°C. The reaction mixture was stirred continuously for 2 hours and the supernatant was collected in the interval of half an hour and kept for analysis. The nutrient components present in the supernatant represent the soluble components were quantified by ICPMS & HPLC.
Intestinal Digestion: Intestinal fluid was prepared to setup an experimental digestion process. 6.8 g of monobasic potassium phosphate was dissolved in 250 ml of water .To this 77 ml of 0.2N sodium Hydroxide dissolved in 500 ml of water was mixed and stirred. 10 g of pancreatin was added and the volume was made up to 1000 ml with distil water. The pH was adjusted to 6.8 – 7 with 0.1 N sodium hydroxide solutions. Before the start of the intestinal digestion, the samples were neutralized to pH 5.5–6 prior to the addition of pancreatin which includes pancreatic enzymes such as pancreatic amylase, lipase, ribonuclease, and proteases such as trypsin and bile salts. The final pH is adjusted between 6.5 & 7.
Digestion process: Weighed amount of mineral were added to 50ml of intestinal juices in a beaker. The mixture was stirred for 2 minutes. The beaker was placed in a shaker incubator which was set at 50 rpm. The temperature of shaker incubator was maintained at room temperature 37°C. The reaction mixture was stirred continuously for 2 hours and the supernatant was collected in the interval of half an hour and kept for analysis. The nutrient components present in the supernatant represent the soluble components and were analysed by inductively coupled plasma spectroscopy (ICP), high performance liquid chromatography (HPLC). Figure 2 illustrates release profile of folic acid loaded on silica in simulated gastric and intestinal fluid. Figure 4 illustrates the release profile of iron from the silica in simulated gastro-intestinal fluid.

Example 9
Loading and characterization of calcium onto Silica
Calcium Chloride was used as precursor for the loading of calcium. Calcium chloride (20g) was dissolved in 100 ml of 2.5 M Sulfuric acid and 2% gelatin solution. 10g of silica synthesized from sodium silicate was added to the solution and left for overnight stirring. The samples were centrifuged at 4000 rpm for 5 minutes and were dried under hot air oven. The dried samples were grinded into fine powder. The powder generated was analyzed by different characterization technique and the loading efficiency was studied. Figure 5 illustrates the release profile of calcium from the silica in simulated gastro-intestinal fluid.

SPECIFIC EMBODIMENTS ARE DESCRIBED BELOW
A nutritional composition comprising silica and an active agent selected from vitamin(s), mineral(s) and combination of mineral(s) and vitamin(s), the silica and the active agent forming a complex, wherein amount of the active agent released from the nutritional composition in intestinal fluid is at least 1.5 times than that released in gastric fluid.
Such nutritional composition(s), wherein the active agent is at least 8% (w/w) of the nutritional composition.
Such nutritional composition(s), wherein the silica and the active agent are in a weight ratio range of 3:1 to 11:1.
Such nutritional composition(s), wherein the mineral is selected from iron and calcium.
Such nutritional composition(s), wherein the vitamin is selected from vitamin B, vitamin C, vitamin D, vitamin E and vitamin A.
Such nutritional composition(s), wherein the silica is food grade mesoporous silica.

FURTHER SPECIFIC EMBODIMENTS ARE DESCRIBED BELOW
A method of preparing a nutritional composition comprising preparing a precursor solution of an active agent selected from vitamin(s), mineral(s) and combination of mineral(s) and vitamin(s); adding food grade silica to the precursor solution to facilitate formation of a complex of silica and the active agent; separating and drying the complex formed in the previous step, such complex being suitable for use as a nutritional composition which releases the active agent in intestinal fluid in an amount at least 1.5 times than that released in gastric fluid.
Such method(s), wherein the mineral is selected from iron and calcium.
Such method(s), wherein the vitamin is selected from vitamin B, vitamin C, vitamin D, vitamin E and vitamin A.
Such method(s), wherein the precursor solution is an aqueous solution or an alcoholic solution depending on the active agent.

FURTHER SPECIFIC EMBODIMENTS ARE DESCRIBED BELOW
A method of preparing a nutritional composition comprising preparing a solution of an acid and gelatin; preparing a mixture of sodium silicate and an active agent selected from vitamin(s), mineral(s) and combination of mineral(s) and vitamin(s); adding the mixture to the solution to facilitate formation of a complex of silica and the active agent; separating and drying the complex formed in the previous step, such complex being suitable for use as a nutritional composition which releases the active agent in intestinal fluid in an amount at least 1.5 times than that released in gastric fluid.
Such method(s), wherein the mineral is selected from iron and calcium.
Such method(s), wherein the vitamin is selected from vitamin B, folic acid and combination thereof.
Such method(s), wherein the acid is selected from sulphuric acid, hydrochloric acid and ortho-phosphoric acid.
Such method(s), wherein the sodium silicate and the active agent are mixed in a weight ratio range of 3:1 to 11:1.

INDUSTRIAL APPLICABILITY
The disclosed nutritional composition is inexpensive, stable in natural environment and suitable for human consumption. It has improved shelf life as compared to nutritional compositions known in the art. The nutritional composition facilitates controlled release of the active agent(s) as the active agent(s) show negligible release in the simulated gastric fluid and considerable amount is released in the simulated intestinal fluid. In the disclosed nutritional composition, when both iron and ascorbic acid are used, ascorbic acid also acts as stabilizing agent for iron. The disclosed method of preparation of the nutritional composition is easy to perform and cost effective.