**4. Physicochemical characterization and evaluation of isolated biomaterial**

#### **4.1 Physicochemical characterization**

The color, odor, taste of isolated biomaterial were physically evaluated. The shape of the biopolymer was also observed under the optical microscope. The color-changing point was determined by using the melting point test apparatus. The isolated biomaterial powder was filled in the capillary tube completely and it was kept in a melting point test apparatus (Cystronics). The apparatus was switch on and observed for the temperature at which color changing was observed and melting of biomaterial starts. The temperature was observed with the help of a thermometer. The organoleptic properties like color, odor, taste were observed. The pH was determined for 1% w/v aqueous solution with the help of a digital pH meter (Cystronics). The tests were performed in triplicate (n = 3) and reported [4, 51–57].

#### **4.2 Solubility**

The solubility study of the isolated biopolymers was performed in different solvents like water, acetone, methanol, ethyl acetate, 10%w/v hydrochloric acid *Biopolymer: A Novel Bioexcipient DOI: http://dx.doi.org/10.5772/intechopen.97191*

solution, and diethyl ether and reported. The excess of the isolated biomaterial was added in 10 ml of the specific solvent system in the beaker gradually. The solution was dispersed well and kept for 24 hours on an orbital shaker for achieving an equilibrium state.

Then the solution was centrifuged at 400 rpm in the centrifuge for 10 minutes and then filtered to get the clear solution. Then the filtrate was allowed for measurement in a UV spectrophotometer machine (Mapada). The procedure was performed in triplicate for each isolated biopolymer [4, 25, 56–59].

### **4.3 Particle size analysis**

This was performed by using the optical microscopy method. The isolated biomaterial was taken on the glass slide and added 1 drop of glycerin. The coverslip was placed on the drop and examined with the help of calibrated eyepiece micrometer under the optical microscope. During the examination, about 100 particles were counted and the particle size distribution was determined [56]. This was performed in triplicate, calculated, and reported with the help of the following equation.

$$\mathbf{Xg} = \mathbf{10x} \boxed{} \left( m \mathbf{i} \,\mathrm{log} \mathbf{Xi} \right) / \mathrm{N} \,\mathrm{J} \tag{1}$$

Xg is geometrical mean diameter, ni is the number of particles in range, Xi indicates to the midpoint of the range of particle size and N refers to a total number of particles.

### **5. Flow property**

#### **5.1 Bulk density**

The bulk density of the isolated biomaterial powder was calculated by taking accurately pre-weighed biopolymer in the measuring cylinder and then the bulk volume of the filled powder was measured. This was performed in triplicate. The bulk density was calculated and reported [56].

#### **5.2 Tapped density**

Tapped density of the isolated biomaterial was determined by taking a preweighed biopolymer in a measuring cylinder and then tapped for 100 tappings. Then the tapped volume was determined. This was performed in triplicate. The tapped density was calculated and reported [56].

#### **5.3 Angle of repose**

The angle of repose of isolated biopolymer was determined by the funnel method. Accurately weight the biopolymer was taken in the funnel. The funnel was adjusted at a height so that it just touches the apex of a heap of biopolymer powder. The powder was subjected to flow through the funnel freely on the surface. This was performed in triplicate. Thus the angle of repose was calculated and reported. The obtained results were correlated with <25- with excellent flow, 25–30 with good flow, and 30–40 –passable [60–62].
