*3.1.1 Controlled drug delivery*

In general, the structure of alginates gels is containing pore size (~5 nm) assist to fill this space by low molecular weight drugs through each of two chemical or physical bonding. When a loaded drug comes in association of an watered environment, the drug release is controlled [61]. Furthermore, the loaded drug porters are water dissoluble and may g0 through degradation in an watered medium, consequently crosslinking alginates with bivalent or trivalent cation will increase the strength of the gels or films.

These belongings help researchers to study the kinetics of drug release. The sodium salt of alginic acid and polyethylene oxide blends are described for controlled release of Valganciclovir HCL *in vitro*, as an anti-HIV drug [61, 63]. Tablets and capsules are the potent exemplification of ordinary oral drug dosage forms and can be prepared into immediate release systems for implementation rapid absorption of the drug. The diagrammatic representations showing in **Figure 2**. The release amount of the drug can be retarded by the coating of rapid release systems. For this type of coating, alginates are broadly used. For rapid release dosage forms, alginic acid is play an important role for tablet as a disintegrant and sodium alginate can be used as

**Figure 2.** *Oral drug delivery using alginate nanoparticles [61, 62].*

*Introduction to Alginate: Biocompatible, Biodegradable, Antimicrobial Nature and Various… DOI: http://dx.doi.org/10.5772/intechopen.110650*


**Table 1.**

*Alginate based carrier systems containing active substances and their applications.*

a tablet binding agent [64, 65]. The drug dosages forms are released in a controlled manner from formulation by using a physical or chemical barrier. In the case of oral dosage forms, the barrier can made using different techniques including coating of active agent or entrapment of active agent into polymer matrix [62]. For the design of dosage forms like immediate release system and sustained release system, the alginate is commonly used. The given **Table 1** shows alginate based carrier containing active substances and there applications.

#### *3.1.2 Food industry*

In food industry, restructured foods are manufactured with different shape and size by improving the texture, esthetic and structural properties, which provide the novelty in product to meet demands of consumers [66]. Alginate is approved by FAO/WHO as a safest food additive because of its unique food applications. Alginate is used in various of food products include ice cream toppings, fruit jams, jelly, milk products, food packing, instant noodles, beer etc. [67]. Alginates are important for stability of food products under low and high temperatures. Gelation rate and gel strength of alginates are control by concentration of Ca2+ and H+ in solution [68]. In the current scenario the growth and development of alginate-based food packaging has been carried out. In the case of short-term packaging biodegradable and renewable biopolymers are widely used. For long term storage purpose bioactive agents are merge with alginate films could be released to overcome lipid oxidation, microbial growth in foods and also enhances their self-life [69]. The alginates films synthesized through incorporating cottonseed by-product, biologically active protein hydrolysate contains good antimicrobial and antioxidant properties of lipids and pH adjustment increase their visible light and lipid barrier properties [69, 70]. Some natural and chemical additives are essential for the protection

of food materials, these additives are enhance functional, mechanical, nutritional properties of food products. Alginates are useful in ice cream industry employed as a gelling agent, thickening agent and stabilizing agent. Alginate overcomes the syneresis and provides freeze/thaw stability to bakery creams. It also gives desirable melting characteristics, overcomes shrinkage, crystal formation and enhance heat shock resistance [70].

#### *3.1.3 Protein delivery*

Alginates are playing crucial role in entrapment of protein drug because it overcome or avoid the denaturation and can protect from deterioration until their release. Alginate gels can also be controlled the rate of release of protein [71]. Alginate hydrogels reversible binds with heparin binding growth factors include vascular endothelial growth factor or fibroblast growth factor and lead to the sustained release due to its adaptable property [71]. Highly polydispersed index proteins, include lysosome and chymotrypsin, are successfully cross linked with alginate microsphere. The sodium alginate is useful for cross linking and constant release system.

### *3.1.4 Cell delivery*

The arginine glycine aspartic acid peptides (RGD) contain alginate gel has been employed in vitro cell culture due to their non-immunogenicity, biocompatibility and ease of administration in the body [72]. RGD peptides in alginate gel is responsible for the improvement of phenotypes of interacting myoblasts, chondrocytes, osteoblasts, ovarian follicles and include bone marrow stromal cells. Chemical fusion is responsible for enhancement in adhesion and proliferation of RGD peptides to the alginate backbone, in disparity with non-modified Alginate [72, 73]. Density of RGD in gels is an important factor for growth and cell adherence number. Cellular responses can be persuade by fluctuation in length of spacer arm between RGD peptide and alginate chain.

#### *3.1.5 Wound dressing*

Alginate based wound dressing provides numerous advantages over the gauge [74]. The presence of pathogens into wound can be inhibited by keeping wound in dry condition, whereas moist wound form provided by dressing with Alginate makes it easier in wound healings [74, 75]. Silver with Alginate in wound dressing can be increased antimicrobial activity and antioxidant property of Alginate, which leads to improvement in binding affinity for elastases, matrix metalloproteases-2 and proinflammatory cytokines or immune regulators (TNF-α, IL-8) [75]. Established on scaffolds alginate polyethylene glycol, methyl ether methacrylate and M. oleifera, aloe vera with wound healing property is prepared by using alginate treated calcium ions (Ca2+) this is responsible of the development of an egg box structure due to interconnection between calcium and guluronate blocks of alginate [76]. Because of its bad integrity for tissue scaffolding, it guide to handling and stability problems [77]. Therefore, to solve this trouble, plasticization can be introduced, which is overcome the intermolecular attraction forces in between polymer chains by maintaining alginate plasticizer ratio. As a outcome, it guide to an development in the handling and stability of alginate. Handling and stability problems

*Introduction to Alginate: Biocompatible, Biodegradable, Antimicrobial Nature and Various… DOI: http://dx.doi.org/10.5772/intechopen.110650*

can be solved by addition of plasticizer including polyethylene glycol, methyl ether methacrylate in optimum ratio [78].

#### **3.2 Alginates in cosmetics**

Researchers have been researching alginates for long time to make high quality products in cosmetic industry domain that provide unique benefits to skin. Alginates are capable to absorb UV rays, overcome sun's harmful effects, act as a moisturizer of epidermis, skin smoothening and make sure small cells renewal [79]. Alginates are reported for gel formation can thicken and maintain moisture, are useful for varieties of cosmetics products. Due to gel forming nature, alginate assists in the retention of lipstick color on lips and body lotion moisturizers as well as face creams [80]. To make demandable all round body lotions, alginate act a natural thickener agent is incorporated in sunflower wax. Alginates are an example of natural polysaccharide that contained a very high viscosity and has a strong water absorption potential. Alginates viscosity can be optimized to make sure maximum viscosity [81]. Alginates are explored for face masks and antiaging masks which slow down wrinkles and lift the skin, even aging process. Also, alginates are useful in Dentures which removable set of replacement teeth and gum tissue with complete backing and attractive appearance [82]. Alginates application in dentures are a removable set of restorative dentistry and gum tissues that can provide us with both complete backing and beautiful appearance even at older age.

#### **3.3 Textile industry**

Substrates for color paste can prepare using textile grade alginates in use of design in print fabrics, shawls, towels and extensive range of textile products. Alginates are used as a cleaner and easier to decompose substrate for textile printing compared with other substrates [83]. Alginates can use in printing cotton, jute, and rayon allows for easier handing out of wastewater. Sodium alginates can use as a thickeners in textile industry for purpose of printing to thicken dye paste. Screen roller printing instruments may be used to apply the pastes to cloth. Alginates became general thickeners with the discovery of reactive dyes. Cellulose content of clothes is chemically reacted with these substances. Many famous thickeners, including starch, chemically respond to reactive dyes, resulting in lower color yields and sometimes difficult to wash out by products [84]. Alginates can act as a strongest thickeners for reactive dyes because they non-reactive with dyes and rapidly washout from the finished textile. In traditional screen roller printing the alginate of medium used to high viscosity, although in modern high speed roller printers even low viscosity alginates are giving very attractive printing [84].

#### **3.4 Welding rods**

Welding is very famous and useful technique to making all kind of structures with metals. In the welding procedure coating is used as a flux and to detection of situations near the weld including temperature, oxygen and hydrogen [85]. In this instance, sodium silicate can mix with dry coating ingredients to give some of plasticity requires for coating extrusion into rod and to tie dried coating to the rod. The silicate, in the other side, neither binds nor giving adequate lubrication to allowed to successfully and smooth extrusion [86]. A lubricant and a binder have need of to keep the damp mass together before extrusion and to hold on to coating on rod in from throughout drying and baking. To achieve these standards, alginates can use.

#### **3.5 Alginates used in animal feeds**

Alginate salts of sodium and potassium can widely use as industrial substances including emulsifiers, stabilizers, thickeners, gelling agents, and binders. There is no capable authority possesses recommended usage of sodium alginate in feeding stuffs for dogs, other non-food producing animals, and fish [87]. Whereas potassium alginate can use for feed in cat and dog as food. The alginates are useful for the fish feed has no bad effect on the consumer. Alginate can provide little bit irritating to eyes but not to skin [88]. The application or appearance of these ingredients in fish feed poses no bad effect to aquatic environment. A gel type livestock feed mixtures are made up by mixing feed nutrients, water, alginate, and a water insoluble calcium content from reacting with alginate [89]. The calcium component is soluble in water or the sequestrate affecting reactivity between alginate and calcium component is extracted after the feed mixture is formed, resulting in a gel feed containing the feed nutrient ingredients [90]. The livestock can then be fed the gel meal.

#### **3.6 Biotechnological applications**

The Alginate provides a solid support through matrix shields incorporating biological agents via immobilization from chemical and physical agents initiates protection of microbial cells opposite various atmospheric conditions of reaction media include pH, temperature and shear stress [91]. There are very wide applications of immobilized cells compared to those of free cells in biotechnological processes. Microfluidic are very famous technique to immobilized microbial cells within micrometric and monodisperse particles, which is applicable in bioprocessing advancement [91, 92]. Microorganisms, mammalian cells and proteins are immobilized by alginate microparticle. Cell isolation, cellular reaction to different stimuli and cell division techniques has been inspected by immobilization of cells through a microfluidic method. At high alkaline pH, lipase enzyme biosynthesized by *Bacillus subtilis* through submerged fermentation process be visible good thermal stability and enzymatic activity [91–93]. However, when *Bacillus subtilis* is immobilized in alginate microparticles through microfluidic method, increases lipase production when immersed in the bioreactor. The non-desirable turbidity in final product of industrial processed fruit-based beverages is one of the huge problems, the reason behind this problem is presence of inner cell walls of the polysaccharide including pectin, cellulose, hemicellulose, starch and lignin particulate suspension [94]. In fruit juices pectin are responsible to cause turbidity, and unwanted solid suspension can be degraded and removed by employing enzyme pectinase.

#### **3.7 Environmental applications**

Adsorption technique is more reliable technique for the treatment of environmental contamination. The pollution control in water and waste water including heavy metals, industrial dyes, pesticides and antibiotics etc. can be removed by assistance of alginatebased composites, which is considered as the most effective adsorbent [95]. Alginates are carboxyl and hydroxyl groups rich, thus capable to targeting pollutants including heavy metals and dyes by arresting metallic or cationic ions via ion exchange by cation

*Introduction to Alginate: Biocompatible, Biodegradable, Antimicrobial Nature and Various… DOI: http://dx.doi.org/10.5772/intechopen.110650*

cross linking. The limitations of alginate gels are poor mechanical properties, elasticity, high rigidity and fragility [96]. To overcome these limitations, organic and inorganic alginate-based composite have been synthesized in proper manner.

#### **3.8 Liposomes**

Liposomes are the biodegradable and biocompatible carriers with biological cell membrane properties and these possess intensive delivering property as exposed in newly accepted marketable products [97]. Liposome is reported as a novel drug delivery system for the delivery of pharmaceutical and biomedical products. They contain the ability to incorporate hydrophilic as well as lipophilic drugs due to their high flex. Liposome enhance the therapeutic index and improve the biodistribution of therapeutics [98]. Liposomes have wide variety of applications on top of free drug administrations, inclusive of treatment monitoring, diagnosis, and drug delivery. In case of their antitumor activity of chemotherapeutic agents, the drug loaded liposome is accumulated on the tumor site because of their increased permeability and retention effect [99]. The toxicity of these agents has been reduce to non tumor tissues, and FDA approved numerous types of liposomes for cancer therapy.

#### **3.9 Microspheres**

Microspheres are small spherical structures, which are free flowing microparticles that have a particle size usually 1 μm to 1000 μm, commonly composed of protein and synthetic polymer. Microparticles are very useful for the controlled release of drugs, vaccines, antibiotics, and hormones. Microspheres contains large surface area and provides an easier evaluation of diffusion and mass transfer character [100]. Small molecules encapsulated by microsphere and command the controlled release of drugs within the body fluid. The utilization of sustained release drug system have proven to reward compared by way of traditional dosage forms, as they are free to overcome toxicity and make larger the effectiveness of the drug. Stability studies specified that Eudragit S-100 coated sodium alginate microspheres of naproxen sodium indicated constant a constant degradation rate of microspheres with 2 years shelf life of the formulation when it is accomplished under accelerated conditions and at room temperature [34].

#### **3.10 Microcapsules**

Microcapsules has interior core and exterior shell, which is combination of polymer liquid and solids, can be engulfed, which makes this delivery system for food and agriculture industry applications. Probiotics are use to treat gastrointestinal unevenness but are unsteady in gastrointestinal tract environment [101]. This problem is reduce by the use of double alginate coating microencapsulation of probiotics including *Lactobacillus plantru* and *Lactobacillus casei*. Microencapsulation enhance aliveness of probiotics in simulated gastric fluid, simulated intestinal fluid and also increases temperature resistance. Canthaxanthin is a functional pigment of *Dietzia natronolimnea,* and it is containing high antioxidant properties [102]. They are sensitive to light, oxygen, pH, and heat. Canthaxanthin is microencapsulated in alginate and alginates with high methoxy pectin promote retention in both neutral and acidic pH. These enhance antioxidant properties of canthaxanthin. Currently, the advanced technology of the insulin release system reported for the treatment of Type-1 diabetes mellitus [103]. Under this technology, hyaluronic easy to commercially available films are synthesized, and this decreases the thermal decay of alginate films in comparison of chitosan or starch films.
