DESC:
Priority Claim:

[0001] This application claims priority from the provisional application numbered 202141005202 filed with Indian Patent Office, Chennai on 8th February 2021 and postdated to 8th March 2021 entitled “A process for micro-encapsulation of biomolecules”, the entirety of which is expressly incorporated herein by reference.
Preamble to the Description

[0002] The following specification describes the invention and the manner in which it is to be performed:
DESCRIPTION OF THE INVENTION
Technical field of the invention
[0003] The present invention relates to a process for micro-encapsulation of biomolecules or herbal extracts. More particularly, the invention relates to the specific process of encapsulation using polysaccharide-based ingredients with the reinforcement of plant-based fibers to enhance the stability of encapsulated matrix.
Background of the invention
[0004] Encapsulation or micro-encapsulation is a commonly used process in which bioactive molecules are surrounded by a coating to give a micro-capsule wherein the biomolecule is trapped inside, with desirable properties, dosage, and controlled release for a specific purpose. Micro-encapsulation, as a process is generally used to incorporate food ingredients, biomolecules, enzymes, cells, or other materials on a micro metric scale.
[0005] Microencapsulation is used to enclose substances in different forms, such as, solids, liquids, or gases inside a micrometric wall made of hard or soft soluble film, where the dosage, quantity and release time of bioactive molecule is controlled, and such encapsulation prevents the degradation of bioactive molecules including pharmaceutical molecules. Basically, a micro-capsule is a small sphere comprising a wall enclosing bioactive molecule. This enclosed material in the microcapsule is referred to as the core, internal phase, or fill, whereas the wall is also called a shell, coating, or membrane.
[0006] The materials for micro-encapsulation mostly include lipids, polysaccharides, and polymers, such as alginate and these materials are used as a mixture to trap the bioactive material of interest inside the micro-capsule. The size of the particles to be encapsulated usually range in the micrometer to millimeter, for protection and/or later release in a controlled manner.
[0007] Micro-encapsulation method has been commonly used in the nutraceutical and food industry to act as a protective barrier for the ingredients and to deliver them in such a way that the active molecule is protected without any change in form and property against the harsh environmental conditions, such as fluctuating oxygen level, light, moisture content, attack by free radicals etc. Further, the process of micro-encapsulation of the biomolecule also helps in controlling release and dosage of the bioactive molecule.
[0008] Spray drying is one of the most widely used steps for micro-encapsulation of molecules, such as, phytochemicals, enzymes, food flavors, fragrances, pharmaceutical molecules, cosmetics substances etc. as it provides rapid evaporation of water and maintains the low temperature in the encapsulated particles. Before subjecting to spray drying, the material used for wall or shell of the capsule is mixed with the suspension containing encapsulated components through intensive homogenization. However, the disadvantage of spray drying method is that the conventional spray drying products may undergo the degradation, hydrolysis, and oxidation to some extent while exposed to the environment and may interact with other compounds.
[0009] The Patent Application No. CN1917946A entitled “Continuous multi-microencapsulation process for improving the stability and storage life of biologically active ingredients” discloses microcapsules, and a continuous micro-encapsulation water-in-oil-in-water microencapsulation process through in situ and interfacial polymerization of the emulsion. The formulation comprises a continuous water phase having a dispersion of microcapsules which contain oil drops and wherein the inside of each oil phase drop -containing optionally oil-soluble materials- there is a dispersion of water, or aqueous extract or water dispersible material or water-soluble material. The oil drops are encapsulated with a polymerizable material of natural origin. Such microcapsules are appropriated for spray-dry processes, to be used as dry powder, lyophilized, self-emulsifiable powder, gel, cream, and any liquid form. The active compounds included in the microcapsules are beneficial to the health and other biological purposes. Such formulations are appropriate to be incorporated in any class of food, especially for the production of nutraceuticals, as well as cosmetic products (such as rejuvenescence creams, anti-wrinkle creams, gels, bath and shower consumable products and sprays). The preparations are adequate to stabilize compounds added to the food, media for cultivating microbes and nutraceuticals, especially those which are easily degradable or oxidizable.
[0010] The Patent Application No. US5225278A entitled “Process for microencapsulation” discloses a process for encapsulating a wide variety of target materials, including both hydrophilic and hydrophobic materials, employs condensation of two reactive compounds to form shells around core phase particles including target material dispersed in a continuous phase. One of the reactive compounds has at least two active methylene functional groups per molecule, the other being an active methylene-reactive crosslinking agent. Either type of the reactive compounds can be dispersed in the continuous phase, the other being dispersible in the core phase. Applications include controlled release microencapsulation of agriculture chemicals and biocides.
[0011] The Patent Application No. WO1996032191A1 entitled “Microencapsulation process” discloses a process for microencapsulation of materials by means of complex coacervation employing gelatin and polyaspartic acid. Material to be encapsulated is emulsified in an aqueous solution of gelatin. Polyaspartic acid or a salt thereof is employed to provide a counter ion to the gelatin which, when induced to precipitate from solution by cooling and/or pH change forms a wall around the material. The wall is hardened by crosslinking to form a stable microcapsule containing the material.
[0012] The existing micro-encapsulation process by spray-drying is also associated with additional drawbacks such as, low drug loading capacity of active molecules, less stability due to the degradation by the environmental factors, resulting in insufficient stability, active molecule degradation with interaction with other compounds and variable kinetics of distribution process.
[0013] Hence, there is a need for process of preparation of microencapsulation the biomolecules and herbal extracts using polysaccharide-based ingredients with the reinforcement of plant-based fibers to improve the stability of the encapsulated matrix without affecting the form and properties of the biomolecule.
Summary of the invention
[0014] In order to overcome the drawbacks of the state of art, the present invention provides a process for micro-encapsulation of biomolecules and herbal extracts using polysaccharide-based ingredients with the reinforcement of plant-based fibers to improve the stability of the encapsulated matrix.
[0015] The process of the present invention starts with a pre-emulsion step which is initiated by weighing polysaccharide at a concentration in a range between 30%-60%, crosslinkers at a concentration in a range between 5%-10% and natural fibers from plant extracts such as Ashwagandha, Ginger or Turmeric at a concentration in a range between 5%-20%. The polysaccharide, crosslinkers and natural fibers are dissolved under slow stirring in demineralized water for 10 minutes at an ambient temperature of 36.4°C and the dissolved mixture is subjected to high shearing at 3000 rpm and the active ingredient at a concentration in a range between 25%-40% is slowly added to the solution for encapsulation at the ambient temperature of 36.4°C. This is followed by subjecting the entire pre-emulsion to high shearing at 3000 rpm and homogenization at 800 bar pressure for the micro-encapsulation. The slurry thus formed is spray dried at inlet temperature 180° C and outlet temperature 102°C with a pressure of the order of 2 bars inside and using a 1 mm diameter injection nozzle to obtain the fiber reinforced encapsulation matrix.
[0016] The microcapsule thus formed by the present process comprises a core and a shell. The core comprises the biomolecule and the shell plays a very important role to maintain integrity and release of the biomolecule.
[0017] The use of natural nanofibers from plant extracts and cross-linking of the nanofiber with the polysaccharides in the process enhances the physical stability of the biomolecule encapsulated and the loading capacity of the biomolecule.
[0018] In addition, the spray drying used during the process of the present invention results in the development of the novel fiber reinforced polysaccharides formulation, which increases the stability of the encapsulated biomolecule thus reducing the rate of degradation.
[0019] The process is simple, cost-effective, capable of easily scaling-up and is associated with improved physical stability, high-rate entrapment of hydrophobic drugs, controlled particle size with extended release of the biomolecule.
Brief Description of drawings
[0020] FIG 1 illustrates the process of encapsulation of biomolecules according to an embodiment of the invention.
Detailed description of the invention
[0021] In order to more clearly and concisely describe and point out the subject matter of the claimed invention, the following definitions are provided for specific terms, which are used in the following written description.
[0022] The term “Biomolecule” refers to bioactive molecules such as food ingredient, enzyme, herbal extract etc.
[0023] The term “Micro-encapsulation” refers to a process in which tiny particles or biomolecules are surrounded by a coating or a shell to give small micro-capsules, with desirable properties, dose, and biomolecule release time.
[0024] The term “Spray drying” refers to a process used for micro-encapsulation of molecules, and it provides rapid evaporation of water and maintains the low temperature in the encapsulated particles.
[0025] The present invention relates to a process of micro-encapsulation of biomolecules and herbal extracts using polysaccharide-based ingredients with the reinforcement of plant-based fibers to improve the stability of the encapsulated matrix.
[0026] The microencapsulation of the present invention discloses the use of natural nanofibers from plant extracts to improve the physical stability. The presence of cross-linking of the nanofiber with the polysaccharides is associated with increased stability. These plant nanofibers fibers reinforce with the polysaccharides and retain the spherical structure of the matrix thus stabilizing the core structure from the degradation.
[0027] The reinforcing fibers are utilized in the present invention to prepare the mechanically strong powders with significantly high thermal stability and less degradation. Therefore, the final product so obtained is a very conducive product for the controlled and sustained delivery of various types of biomolecules including but not restricted to antioxidant, anti-inflammatory molecules, and vitamins.
[0028] Spray drying is one of the commonly used physical method of micro-capsulation, especially when the bioactive molecule is dissolved or suspended in a polymer solution and becomes trapped in the dried particle. The main advantages of this technique are the ability to handle sensitive materials because of the short contact time in the dryer and the operation is economical. Applying this technique, along with the use of supercritical carbon dioxide, sensitive materials such as proteins are encapsulated with ease.
[0029] More specifically, fiber reinforced spray drying of polysaccharides, as used in the present invention, is an excellent way for the preservation of the activity and integrity of the herbal as well as nutraceutical molecules.
[0030] Spray drying method is used in the present invention develop the novel fiber reinforced polysaccharides formulation.
[0031] FIG 1 illustrates the process of encapsulation of biomolecules. The process (100) of microencapsulation of the present invention starts at a pre-emulsion step (101), which is obtained by accurately weighing the amounts of polysaccharide at a concentration in a range between 30%-60%, crosslinkers at a concentration in a range between 5%-10% and natural fibres from plant extracts such as Ashwagandha, ginger or turmeric at a concentration in a range between 5%-20%. The polysaccharides include gum Arabic, modified food starch or dextrins. The crosslinkers include Polyethylene Glycol (PEG), Propylene Glycol (PG) and glycerine. At step (102), the polysaccharide, crosslinkers and natural fibres are dissolved under slow stirring in demineralized water for 10 minutes at an ambient temperature of 36.4°C. At step (103), the dissolved mixture is subjected to high shearing at 3000 rpm in a Primix T.K. Homomixer Mark II, Model 2.5 and the active ingredient such as ashwagandha, Vitamin E, or Resveratrol at a concentration in a range between 25%-40% is slowly added to the solution for encapsulation at the ambient temperature of 36.4°C. At step (104), the entire pre-emulsion is subjected to further high shearing at 3000 rpm and homogenization at 800 bar pressure for the micro-encapsulation. At step (105), the slurry is spray dried in Lab Plant spray drier SD05, which is pre-heated at 100° C, the process of spray drying is carried out at inlet temperature 180° C and outlet temperature 102° C with a pressure of the order of 2 bars inside and using a 1 mm diameter injection nozzle to obtain the fiber reinforced encapsulation matrix.
[0032] The use of natural nanofibers along with polysaccharides for micro-encapsulation enhance the stability of the micro-encapsulated biomolecule and improves the loading capacity of active biomolecules. The conventional encapsulation is generally achieved using polysaccharides such as dextrin, gum Arabic, proteins and starch that results in degradation under varied environmental conditions such as fluctuating oxygen levels, light, heat, moisture, and free radicals.
[0033] The nanofiber reinforcement with the polysaccharides provides a stronger encapsulation of the biomolecules by cross-linking ability of the fibers. Moreover, these nanofibers also aid in retaining the core structure intact and well reinforced with the polysaccharides.
[0034] The micro-capsule prepared by said process consists of a core and a shell. The core comprises the biomolecule and the shell or capsule coat wherein capsule coat plays a very important role to maintain integrity and release of the biomolecule.
[0035] The formulation of encapsulating material represents a new type of microencapsulation system for sustained delivery as well as enhanced stability of bioactive compounds. The active biomolecules are well dispersed inside the fiber reinforced polysaccharide wall or the capsule to retain the overall spherical structure of the micro-capsule. In addition, the permeability, and the stability of the microencapsulate is enhanced as the core structure is amphiphilic in nature.
[0036] The microcapsule prepared by the process of the present invention is associated with improved physical stability, high-rate entrapment of hydrophobic drugs, controlled particle size with extended release of the biomolecule. The process is simple, cost-effective as it involves low cost of ingredients, ease of preparation and scale-up.

,CLAIMS:We Claim,
1. A process for micro-encapsulation of one or more biomolecules, wherein the process (100) comprises the steps of:
a. accurately weighing polysaccharide at a concentration in a range between 30%-60%, crosslinker at a concentration in a range between 5%-10% and natural fibres from plant extracts at a concentration in a range between 5%-20% (101);
b. dissolving the polysaccharide, crosslinkers and natural fibers with slow stirring in a demineralized water for 10 minutes at an ambient temperature of 36.4°C (102);
c. subjecting the dissolved mixture to high shearing at 3000 and slowly adding the active ingredient at a concentration in a range between 25%-40% to the solution for encapsulation at the ambient temperature of 36.4°C (103);
d. subjecting the pre-emulsion to further high shearing at 3000 rpm and homogenization at 800 bar pressure for the micro-encapsulation (104); and
e. spray drying the slurry in a Lab Plant spray drier SD05, which is pre-heated at 100°C, wherein the process of spray drying is carried out at inlet temperature 180° C and outlet temperature 102° C with a pressure of the order of 2 bars inside and using a 1 mm diameter injection nozzle to obtain the fiber reinforced encapsulation matrix

wherein nanofiber reinforcement with the polysaccharides provides a stronger encapsulation of the biomolecules by cross-linking ability of the fibers.

2. The process as claimed in claim 1, wherein the polysaccharide is selected from a group comprising gum Arabic, modified food starch and dextrin.

3. The process as claimed in claim 1, wherein the crosslinker is selected from a group comprising Polyethylene Glycol (PEG), Propylene Glycol (PG) and glycerine.

4. The process as claimed in claim 1, wherein the active ingredient is selected from a group comprising ashwagandha, Vitamin E, and Resveratrol.

5. The process as claimed in claim 1, wherein the presence of nanofibers and polysaccharides enhance the loading capacity and stability of the micro-encapsulated biomolecule.

6. The process as claimed in claim 1, wherein the active biomolecule is dispersed inside the fiber reinforced polysaccharide wall or the capsule to retain the overall spherical structure of the micro-capsule.

7. The process as claimed in claim 1, wherein the presence of reinforcing fibers to enhance the thermal stability such that reducing the rate of degradation of the micro-encapsulated biomolecule.

8. The process as claimed in claim 1, wherein the micro-capsule prepared by said process comprises a core and a shell, wherein the core comprises the biomolecule and the shell maintains the integrity and release of the biomolecule.