Characterization of Gelatin a Biopolymer for Drug Delivery

INTRODUCTION

Drug Delivery has become an interesting in the present day bringing together Material Science Engineering, Mechanical Engineering, Bio-medical Engineering and Pharm-ology together. This method helps to provide an effective way to use a compound to achieve a therapeutic effect in humans and animals. The technique involves modification of drug release profiles, absorption, distribution and elimination for the benefit of improving product efficacy, safety, as well as patient compliance and convenience.

Gelatin is a naturally occurring macromolecular and bio degradable protein that is obtained from skins, tissues and bones of animals. It has high water solubility, non toxicity, high mechanical strength and elasticity in dry state making it a perfect material for drug delivery. There are two kinds of Gelatin. Type A, with isoionic value of 7 to 9, is inferred utilizing solely corrosive pretreatment. Type B, with isoionic value of 4 to 5, is the aftereffect of an antacid pretreatment.[2]

The usual sources of Gelatin are bovine and pig skins and demineralized bones and hooves. This is a cause for problem for people tend to not consume gelatin based medicines due to religious reasons, mad cow disease and social reasons. To solve this, another source of gelatin was experimented for, extraction of Type B gelatin from fresh water fish L. rohita. In this project we look at its extraction, manufacturing of gelatin and the characteristic properties of the type B gelatin obtained.[1]

PROCESSING

Since there are two sorts of Gelatin, there are two fundamental assembling procedures of Gelatin: Alkaline and corrosive process. The subsequent items can be altogether different as far as piece and physical properties.[4]

Acid handled collagen is absorbed weaken corrosive nature of the acid and after that extricated at about pH 4 for gelatin producing. Non-collagenous proteins and mucoproteins of the tissue are isoelectric at this pH and are consequently not so much solvent but rather more promptly coagulated under the extraction conditions. Contaminants which are expelled along these lines rely upon the quality and birthplace of the raw material and the reproducibility of the producers process.[4]

When managing the basic procedure, the pretreatment of the collagen requires a drawn out absorbing the soluble arrangements (by and large, immersed lime-water). A decent measure of the pollutions (proteins and mucosubstances) are dissolvable at the oppressed pH and are separated. Gelatins from soluble base process will in general be cleaner than corrosive created gelatin, yet this variety might be because of the assembling process.[4]

Moreover to the challenges referenced beforehand, the produce of gelatin is liable to more confusions. For instance the aggregate number of carboxyl gatherings accessible for ionization relies on the extraction technique. Distinctive gelatins can have diverse proportions of acidic and essential gathering in this manner distinctive isoelectric focuses. Charged gatherings impact the cooperations between nearby gelatin atoms, between every particle and the dissolvable and between various parts of a similar atom, as the protein chains are adaptable. The degree of these factors change with pH, and are likewise subject to the aggregate ionic sythesis of the framework in this way an itemized depiction of the dissolvable and additionally that of the gelatin is a necessity.[4]

CHARACTERIZATION

Sample Preparation

Fish scales of L.Rohita having weight of 100-200g were collected at Guntur , Andhra Pradesh , India. The scales were removed using hands, kept in air tight bags and on ice for preservation. Gelatin was extracted using the alkali method. Dried scales were stirred in a solution of 5% NaCl at 30 min room temperature. This step was repeated twice and then the scales were stirred with 4% NaOH to remove the non-collagenous proteins from the scales. To remove lipids from the scales, iso-butyl alcohol was used. This step was repeated three times in a digital linear shaker. The final step was dimineralisation which was done using 0.5N EDTA at a pH of 7.66 for four different time periods of 12h, 2h, 2h and 1h. The scales were then dried on plastic trays and grinded to obtain the gelatin in powder form.[1]

Gelatin Yield

[1]The gelatin yield is given by the following equation

Yield of Gelatin=(Weight of dried Gelatin)/(Dry weight of Fish Scale)?—100

Determination of Gelatin pH

To determine the pH of Gelatin, prepare a 1% gelatin solution in distilled water and cool to 25?°C in a water bath. The pH is then measured.

UV-vis Spectroscopy Analysis

Ultraviolet and Visible absorption spectroscopy is the measurement of the attenuation of a beam of light after it passes through a sample or after reflection from a sample surface. Absorption measurements can be at a single wavelength or over an extended spectral range. UV spectroscopy is used for:

• Detection of functional groups
• Detection of Impurities
• Qualitative analysis
• Quantitative analysis
• Single compound without chromophore
• Drugs with chromophoric reagent

Ultraviolet absorbption spectra arise from transition of electron within a molecule from a lower level to a higher level. A molecule absorbs ultraviolet radiation of frequency(V), the electron in that molecule undergoes transition from lower to higher energy level. The energy can be calculated by

E_1-E_0=hV

The UV-vis absorption spectrum was recorded using a UV vis double beam spectrophotometer in the range of 200-400nm.

Fourier transform infrared(FITR) spectroscopy analysis

FTIR is a technique based on vibrational spectroscopy. AN infrared spectrum is obtained using fourier transforms. Fourier Transfroms help to represent a range of Sinusodial waves as a single summition function. Presently FITR has replaced the dispersive method as it has a higher signal to noise ratio.[3]

The IR enters the interoferometer. It has a beam splitter and 2 mirrors. The beam splitter splits the radiation, One beam strikes a moving mirror and one beam strikes a fixed mirror. The two beams then combine and intract with the sample and then go to the detector. The difference in wave length is plotted and then used to determine a fourier transform.[3]

100 mg of KBr and 2mg of Gelatin was mixed and placed in FITR equipment. FITR was performed at room temperature and measurements were taken.

X-Ray diffraction

To determine the Crystal structure, X ray diffraction was used. The operating voltage was 45kV and the operating current was at 40mA. The radiation used was Cu K?±.[1]

Scanning Electron Microscopy

Scanning Electron Microscopy was used to determine the surface morphology of Gelatin. Gelatin was coated with gold in a vaccum sputter and a photograph was taken.[1]

RESULTS AND DISCUSSION

Yield of Gelatin

The gelatin extracted was yellow and the weight percentage was 24% which is higher than the yield of red tilapia(7.81%) and black tilapia(5.39%)(found in previous studies)[1]

Characterization results

The UV-vis spectroscopy showed absorption at 224nm, indicating a presence of strong peptide bonds. Absorption at 210-240nm shows the presence of peptide chromophore. Since the operational range was 200-400nm, the results can be considered valid. Refer figure 2.[1]

Figure2. UV-vis absorption spectrum of fish scale gelatin

FITR measurement made it possible to identify the amino groups present. Also it helped to identify the bonds responsible for the structural and functional stabilization. Amino acids are made of amide bonds which can be identified by the specific amide band that is absorbed at the FITR measurement. [1]

Peaks(cm-1) Possible functional bands

3433 Hydrogen bond

1630 Amide-I

1565 Amide-II

1240 Amide-III

1460 Symmetric Bending

1380 Asymmetric Bending

Table 1- FITR results of Gelatin

Figure 3. FTIR spectrum of gelatin

Porosity is determined by Scanning electron microscopy analysis. Porosity characterization is the determination of open pores which determine properties like permeability and the surface area of the porous structure.The microstructure obtained shows that the polymer has an array of hollow cells. Higher density shows greater mechanical strength and the higher porosity shows a better biological environment. The SEM micrograph shows a decent balance between the two.[1] Refer Figure 4.

Figure 4. SEM micrograph of gelatin extracted from fish scale

The XRD diffractogram shows a sharp peak with low intensity at 2??=7?° and a broad peak at 2??=19?°. This is usually assigned to the triple helical crystalline structure of gelatin.[1]

Conclusion

The study shows that L Rohita is a good source of raw material for Gelatin production. It can be determined that gelatin has the necessary porosity for drug delivery and has a triple helical crystalline structure. The FITR shows it chemical bonds. Thus Fish based Gelatin is an effective source of gelatin for drug delivery.

References

Merina Paul Das, Suguna PR, Karpuram Prasad, Vijaylakshmi JV, Renuka M. Extraction and characterization of gelatin: a functional biopolymer. Int J Pharm Pharm Sci 2017;9(9):239-242.

Gavasane AJ, Pawar HA (2014) Synthetic Biodegradable Polymers Used in Controlled Drug Delivery System: An Overview. Clin Pharmacol Biopharm 3:121.doi:10.4172/2167-065X.1000121

Materials Characterization: Introduction to Microscopic and Spectroscopic Methods by Yang Leng, Second Edition (ISBN No. 978-3-527-33463-6) John Wiley & Sons (2013)

Felix, Pascal Georges, "Characterization and correlation analysis of pharmaceutical gelatin" (2003). Graduate Theses and Dissertations. https://scholarcommons.usf.edu/etd/1365

Cite this page