Preparation and Biodegradation Study of Chitosan Copolymers to Colon Delivery

 

M. Kannadasan¹*, S.K. Jain², R.K. Roy³

¹Dr. K. N. Modi University, Newai-304 021(RJ) India.

²Dr. H. S. Gour Central University, Sagar-470 003(MP) India.

 

ABSTRACT:

The scientific research has been transformed from stone age–brass age–iron age–ceramic age–polymer age and now currently to graft polymer age. The natural polymer science and technology has developed tremendously over the last few decades, and the production of natural polymers based drug products has increased at a remarkable pace. Currently, interplay between natural and synthetic polymers is being emphasized to further advancing the drug delivery to second brain (colon). So, take a look at some surprising spinoff from this experimental study of copolymers, which are far more technically superior and reach to difficult to reach the place in gastro intestinal tract.

 

 

 

INTRODUCTION:

Efforts are being made the drug delivery to second brain (colon) by reducing drug waste, and developing innovative products[1-4][6][9]. Since the dawn of development of pharmaceutical science, researchers have developed wide variety of advances in drug delivery system to second brain using various natural and synthetic materials (polymers)[7-8][13] separately for the use of mankind. Current research interests on materials are graft copolymer, and were prepared by suspension polymerization method. The degradation of the copolymers in rat caecal content was performed in Albino rats.

 

MATERIALS AND METHODS:

Chitosan and reagent grade acetic acid, acrylic acid, acryl amide, ceric ammonium nitrate, acetone, were all purchased from CDH and used without further purification. Graft copolymer was prepared by suspension polymerization method. The degradation of the copolymers in rat caecal content was performed in Albino rats. Microscopic appearances of the copolymer were recorded using Magnus binocular microscope.

 

EXPERIMENT:

1. Preparation of Copolymer

Chitosan[10] was first dissolved in 100ml acetic acid aqueous solution (1%v/v) and was stirred with ceric ammonium nitrate for 10 minute in 250ml flat-bottom flask. Then, the aqueous solution of monomer (acryl amide or acrylic acid) was added to the chitosan solution and mixed uniformly for 1h. Polymerization was carried out at 60ºC with a continuous purging of nitrogen gas for 6h in a water bath with constant stirring is represented in Fig.1 and the formula given in Table 1. After complete polymerization, a sufficient amount of acetone was added to precipitate the graft copolymer. Finally, the precipitated graft polymer was washed with water to remove homopolymer. Then it was dried at 35-40°C over night [5].

 

Table 1: Reaction conditions for preparation of copolymer

Formula	Sample(s)	CHI (g)	CAN (mg)	AA (ml)	Am (g)
0	Bare-CHI	2.0	-	-	-
F1	CHI-g-AA1.5	2.0	200	1.5	-
F2	CHI-g- AA3.0	2.0	200	3.0	-
F3	CHI-g- AA4.5	2.0	200	4.5	-
F4	CHI-g- Am1.5	2.0	200	-	1.5
F5	CHI-g- Am3.0	2.0	200	-	3.0
F6	CHI-g- Am4.5	2.0	200	-	4.5

 

CHI         – Chitosan

CAN       – Ceric Ammonium Nitrate

AA         – Acrylic acid

Am          – Acryl amide

Polymerization Temperature – 60°C

Purging gas – Nitrogen

Polysaccharide (Chitosan)       +      Monomer (Acrylic acid or Acryl amide)                                              CAN, Stirring (10 min.)                                                                                                  Stirring (1 h)    Nitrogen gas, 60°C, Stirring (6 h)                                                                   Unreacted Monomer                                                                                 + Homopolymer [Poly (Acrylic acid) or Poly (Acryl amide)]                                                                                                            + Acetone   Graft Copolymer (Chitosan grafted AA or Am)                 Filtrate: Monomer (Unreacted)                                                  Precipitate: copolymer and           Homopolymer Water                                                                                                                                Solution:                        Residue: Graft                                                                                                                Homopolymer               Copolymer (Product)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Fig.1: Schematic representation of steps involved in preparation of graft copolymer

 

 

2. Copolymer degradation study:

Formula, F2 and F6 were selected on the basis of in-vitro physical characteristics studies in order to study ex-vivo performance of prototype copolymer sample with acceptable in-vitro characteristics. The degradation of prepared copolymer (CHI-g-AA_3.0 and CHI-g-Am_4.5) was determined in SCF (simulated gastric fluid, pH 7.2) containing rat caecal content (0% and 6%). The caecum was removed from Albino rats and the contents were weighed and then suspended in SCF that to give desired concentration of 6% of rat caecal content in SCF. As the environment in caecum is anaerobic, all the operations were carried out under CO₂ atmosphere. In the caecal content medium, accurately weighed amount of each copolymer were immersed and incubated for 48h at 30 ± 5ºC, separately. After this, the copolymers were removed from the medium and washed with distilled water, dried and weighed and the microscopic appearances of the copolymer were recorded using Magnus binocular microscope (Olympus India

Pvt. Ltd.). The results are presented in table 2 and 3, shown in the photomicrograph No. 1-4.

 

 

Table 2: Copolymer degradation study in presence of rat caecal content (6%)

Variable	Copolymer
	Before degradation study		After degradation study
	CHI-g-AA3.0	CHI-g-Am4.5	CHI-g-AA3.0	CHI-g-Am4.5
Weight	100mg	100mg	35% loss	25% loss
Shape	Irregular	Irregular	Irregular	Irregular
Surface	Brittle	Brittle	Smooth-with undulation	Smooth-with hole

 

Table 3: Copolymer degradation study in absence of rat caecal content (0%)

Variable	Copolymer
	Before degradation study		After degradation study
	CHI-g-AA3.0	CHI-g-Am4.5	CHI-g-AA3.0	CHI-g-Am4.5
Weight	100mg	100mg	0.8% loss	0.9% loss
Shape	Irregular	Irregular	Irregular	Irregular
Surface	Brittle	Brittle	No change	No change

 

Photomicrographs of Copolymers Before and After Incubation in Rat Caecal Content

 

 

RESULTS AND DISCUSSION:

The copolymer of chitosan grafted vinyl monomers (acrylic acid and/or acryl amide) is successfully prepared(fig.1) and is solid-glassy in nature, color was pale to brown (CHI-g-AA) and pale yellow (CHI-g-Am). The degradation of the selected copolymers (CHI-g-AA_3.0 and CHI-g-Am_4.5) in rat caecal content (6%) study (table 2 and 3) described that both copolymer samples are biodegradable (photomicrograph No.2 and 4). These results revealed that the nature of polymer and the availability of enzymes in colon for the biodegradation of prepared copolymers. Both the formula (F2 and F6) revealed that the developed prototype formula efficiently control in-vivo drug release, (if no enzyme-work, no biodegradation and no release is anticipated) and minimizes systemic absorption and hence reduce systemic unwanted effects of drug is also anticipated from this experimental study model.

 

CONCLUSION:

The prototype chitosan copolymers are assumed to remain intact in the physiological environment except colon, where they are acted upon by bacterial polysaccharidases[3][11-12] and results in the biodegradation and may release the drug, subjects to the toxicity study of copolymers. The developed tailor-made materials with interesting applications and properties to be explored worldwide near future with advanced technology[14].

 

ACKNOWLEDGEMENT:

Authors wish to thank Head, DOPS, Dr. H. S. Gour University, India, for extending all required Lab. facility and other support for the experimental work, and also thank to Director, Dr. K. N. Modi Institute of Pharmaceutical Education and Research, Modinagar, India, for extending Library facility for this work.

 

REFERENCES:

1.        Chien, Y. W., Novel Drug Delivery Systems, Marcel Dekker Inc., New York, 2^nd Ed., (1992). 163.

2.        Friend, D.R. (Ed.), Oral Colon-Specific Drug Delivery, CRC Press, Florida, (1992).

3.        Friend, D. R., Glycosides in colonic drug delivery, CRC Press, London, (1992) 153-187.

4.        Gruber, P., Longer, M.A., and Robinson, J.R., Some biological issues in oral controlled drug delivery. Adv. Drug Deriv. Rev., 1 (1987) 1-18.

5.        Joshi, J.M. and Sinha,V.K., Graft copolymerization of 2-hydroxyethylmethacrylate onto corboxymethyl chitosan using CAN as an initiator, Polymer., 47 (2006) 2198-2204.

6.        Kannadasan, M., Ram Kumar, R., and Vijay Kumar, S., Review Article: Pharmaceutical Approaches to Colon Targeted Drug Delivery Systems., Res. J. Pharm., Biol. Chem. Sci., 5(5), (2014) 1811- 1822.

7.        Kopecek, J., Kopecekova, P., Bronsted, H., Rathi, R., Rihova, B., Yeh, P.Y. and Ikesue, K., Polymers for colon specific drug delivery. J. Control. Rel. 19 (1992) 121–130.

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9.        Mrsny, R.J., The colon as a site for drug delivery. J. Control. Rel., 22 (1992) 15-24.

10.     Sivakumar, S. M., Mohammed, M., Aamena, J., and Kannadasan, M., Pharmaceutical aspects of Chitosan polymer “In Brief”., Research J. Pharm. and Tech. 6(12), (2013) 1439-1442.

11.     Van den Mooter, G. and Kinget, R., Oral colon-specific drug delivery: A review. Drug Delivery 2 (1995) 81–93.

12.     Akala, E. O., Kopeckova, P. and Kopecek, J., Biomaterials, 19, (1998) 1037-1047.

13.     Vyas, S. P. and Khar, R. K., Targeted and Controlled Drug Delivery, CBS Publishers and Distributors, New Delhi, 1^st Ed., (2002) 417-454.

14.     Wilding, I., Coupe, A. and Davis, S., Adv. Drug Del. Rev., 7 (1991) 87-117.

 

 

Received on 19.10.2014          Modified on 27.10.2014

Accepted on 05.11.2014         © RJPT All right reserved