**3. Materials and methods**

Sodium alginate (RM 7494), κ-carrageenan (22,048, Sigma Aldrich), Gelatin, phosphate buffer saline pH 7.4 (PBS, Sigma Aldrich) and curcumin (C1386, Sigma

**83**

at 37°C.

*Preparation and Characterisation of Niosomal Emulsions as Novel Drug Delivery Vehicle…*

**Polymeric concentrations (%)**

> 1 1.5 2 2.5

> 1 1.5 2 2.5

**Salt type Salt concentration** 

CaCl2·KCl 2

CaCl2 2

**(%) (w/v)**

Aldrich) were used without further purification. CaCl2 and KCl were commercial products of analytical grade. Single distilled water (Labsil Water Distiller, Model:

**3.1 Preparation of alginate/κ-carrageenan and alginate/gelatin hydrogel beads** 

Alginate, κ-carrageenan and gelatin solutions were prepared separately by dissolving each of the biopolymers in distilled water and heated up at 50°C (for alginate), 60°C (for κ-carrageenan) and 40°C (for gelatin) under constant stirring from 30 min to 1 h until complete dissolution [50]. Ionotropic method was used for the preparation of hydrogel beads. Polysaccharide mixture composed of 50:50, 70:30, 80:20 (weight ratio) with concentrations varying from 1 to 2.5% (given in **Table 1**) were prepared by mixing under constant stirring at 30°C for 30 min. Briefly the hydrogel beads were prepared by dropping the mixture through a plastic syringe (5 ml) into an aqueous salt solutions stirred magnetically. For the preparation of alginate/κ-carrageenan hydrogel beads, the salt solution was composed of 100 ml of 2% (w/v) KCl and 100 ml of 2% (w/v) CaCl2 and for alginate/gelatin hydrogel beads, 200 ml of 2% CaCl2 solution. To complete gelation, beads were maintained in the solution for 30 min then filtered, followed by washing with distilled water and then allowed to dry

For curcumin loading, 10 mg/ml curcumin prepared with ethanol was mixed with each of the alginate/κ-carrageenan and alginate/gelatin mixtures and stirred until complete evaporation of ethanol. Curcumin loaded beads were prepared by dropping the mixture through a 5 ml syringe into a stirred salt solution which was composed of 100 ml of 2% (w/v) KCl and 100 ml of 2% (w/v) CaCl2 in the case of alginate/κ-carrageenan and 200 ml of 2% (w/v) CaCl2 for alginate/gelatin and kept in the solution for 30 min, filtered, washed with distilled water and dried overnight

Scanning electron microscopy (SEM, LEO 1430 V) was used to analyse the

The swelling degree (SD) was determined gravimetrically as follows: Both the hydrogel beads were immersed in phosphate buffered saline (PBS, pH 7.4) at 37°

*DOI: http://dx.doi.org/10.5772/intechopen.86942*

**ratio (w/w)**

70:30 80:20

70:30 80:20

**Materials Weight** 

Alginate/*κ*-carrageenan 50:50

Alginate/gelatin 50:50

**Table 1.**

OPTI-M4) was used in all experiments.

*Weight ratio percentage concentrations of polymeric solutions.*

**and curcumin loading**

overnight at 37°C.

**3.2 Morphological analysis**

morphology of hydrogel beads.

**3.3 Swelling behaviour**

*Preparation and Characterisation of Niosomal Emulsions as Novel Drug Delivery Vehicle… DOI: http://dx.doi.org/10.5772/intechopen.86942*


#### **Table 1.**

*Role of Novel Drug Delivery Vehicles in Nanobiomedicine*

lambda), alginate, and agar [39].

cause dangerous side effects. These problems can be reduced by the use of natural biocompatible polymer/polysaccharides as carriers for the drug. Seaweeds provide a better source for available polysaccharides such as carrageenan (iota, kappa, and

Monosaccharides combine to form polysaccharides with number of reactive groups that can be easily modified to get various types of polysaccharides. Typical sources of polysaccharide include algae, microorganisms, animals, etc. The positive features of polysaccharides such as higher molecular weight, changing chemical composition and large number of reactive groups gave diversity in its function. Adaptable chemical composition delivers its variety in structure and also in property. Medicinal field exploits these best properties of polysaccharides for the betterment of drug delivery. Drug carriers from polysaccharides make sustainable, cost effective and biodegradable drug carriers. Modification of polysaccharide chains opens a way to target drug to the affected site, altering the solubility, biocompatibility, moisture resistant and particularly reduce the severe side effects from therapeutic agents. Polysaccharides can perform bio adhesion through hydrophilic groups such as carboxyl, hydroxyl and amino groups by making non covalent interaction with biological tissues that elongates residing time. By this the absorption of drug at the particular area can be easily made. In this chapter we discuss niosomal emul-

sions of alginate, *κ*-carrageenan and gelatin as drug carrier [38, 40, 41].

as a thermally reversible gelling agent for encapsulation [45].

phosphate buffered saline (PBS, pH 7.4).

**3. Materials and methods**

Alginates are naturally derived polysaccharide block copolymers composed of β-d-mannuronic acid monomers (M-blocks), α-l-guluronic acids (G-blocks) and regions of interspersed M and G units [38, 42]. Divalent cations such as Ca2+ can induce hydrogel formation by polysaccharide chain association in alginates [20]. Carrageenans represent a family of sulphated linear polysaccharides consisting of (1 → 3)-linked β-galactose and (1 → 4)-linked α-d-galactose units mainly extracted from certain red seaweeds of Rhodophyceae family particularly from *Chondrus crispus*, *Eucheuma gigartina*, *Stellate iridaea*, *Hypnea*, *Solieria agardhiella and Sarconema*, which are variously substituted and modified to the 3,6-anhydro derivative, depending on the nature of origin and extraction conditions [43]. Three main types of carrageenans are known: kappa-*κ*, lambda-*λ* and iota-*i*, depending on the number and the position of the ionic sulphate groups. The presence of a suitable cation, typically potassium, or calcium is an absolute requirement for gelation of the carrageenans, especially kappa [44]. Gelatin is a protein derived from denatured collagen that contains high levels of hydroxyproline, proline and glycine. It is useful

However, we go through the development and characterization of alginate/*κ*carrageenan and alginate/gelatin hydrogel beads and its application in encapsulation of a model hydrophobic potential drug, curcumin. Hydrogel beads were developed via ionotropic gelation. Alginate/*κ*-carrageenan beads were cross-linked with CaCl2-KCl salt solution and alginate/gelatin beads with CaCl2 solution. Drug release behaviour of alginate/*κ*-carrageenan and alginate/gelatin hydrogel beads was compared employing curcumin, which is a natural polyphenolic compound isolated from rhizome of turmeric (*Curcuma longa*) as a model drug [46]. Curcumin is widely known to possess antioxidant [47], antitumor [48], and anti-inflammatory [49] activity. Swelling of the beads and in vitro release of curcumin were studied in

Sodium alginate (RM 7494), κ-carrageenan (22,048, Sigma Aldrich), Gelatin, phosphate buffer saline pH 7.4 (PBS, Sigma Aldrich) and curcumin (C1386, Sigma

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*Weight ratio percentage concentrations of polymeric solutions.*

Aldrich) were used without further purification. CaCl2 and KCl were commercial products of analytical grade. Single distilled water (Labsil Water Distiller, Model: OPTI-M4) was used in all experiments.
