Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 30855
Pharmaceutical Microencapsulation Technology for Development of Controlled Release Drug Delivery systems

Authors: Mahmood Ahmad, Asadullah Madni, Muhammad Usman, Abubakar Munir, Naveed Akhtar, Haji M. Shoaib Khan


This article demonstrated development of controlled release system of an NSAID drug, Diclofenac sodium employing different ratios of Ethyl cellulose. Diclofenac sodium and ethyl cellulose in different proportions were processed by microencapsulation based on phase separation technique to formulate microcapsules. The prepared microcapsules were then compressed into tablets to obtain controlled release oral formulations. In-vitro evaluation was performed by dissolution test of each preparation was conducted in 900 ml of phosphate buffer solution of pH 7.2 maintained at 37 ± 0.5 °C and stirred at 50 rpm. At predetermined time intervals (0, 0.5, 1.0, 1.5, 2, 3, 4, 6, 8, 10, 12, 16, 20 and 24 hrs). The drug concentration in the collected samples was determined by UV spectrophotometer at 276 nm. The physical characteristics of diclofenac sodium microcapsules were according to accepted range. These were off-white, free flowing and spherical in shape. The release profile of diclofenac sodium from microcapsules was found to be directly proportional to the proportion of ethylcellulose and coat thickness. The in-vitro release pattern showed that with ratio of 1:1 and 1:2 (drug: polymer), the percentage release of drug at first hour was 16.91 and 11.52 %, respectively as compared to 1:3 which is only 6.87 % with in this time. The release mechanism followed higuchi model for its release pattern. Tablet Formulation (F2) of present study was found comparable in release profile the marketed brand Phlogin-SR, microcapsules showed an extended release beyond 24 h. Further, a good correlation was found between drug release and proportion of ethylcellulose in the microcapsules. Microencapsulation based on coacervation found as good technique to control release of diclofenac sodium for making the controlled release formulations.

Keywords: ethylcellulose, diclofenac sodium, Microencapsulationtechnology, In-Vitro Release Profile

Digital Object Identifier (DOI):

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2857


[1] H. Arabi, S. A. Hashemi, and M. Fooladi, Microencapsulation of allupurinol by solvent evaporation and controlled release investigation of drugs. Journal of Microencapsulation; 1996, 13: 527-535.
[2] P. B. Deasy, Microencapsulation and related drug processes, (New Yark: Marcel Dekker) 1984, pp 16-20.
[3] G. Cheng, F. An, M. J. Zou, J. Sun, X. H. Hao, Y. X. He, Time- and pHdependent colon-specific drug delivery for orally administered diclofenac sodium and 5-aminosalicylic acid; World J Gastroenterol 2004, 10 (12):1769-1774
[4] A. Kristl, M. Bogataj, A. Mrhar and F. Kozjek, Preparation and Evaluation of ethyl cellulose Microcapsules with Bacampicillin. Drug Develop Ind Pharm; 1991, 18 (8):1109-30.
[5] L. Lachman, H. A. Lieberman, and J. I. Kanig, the Theory and Practice of Industrial Pharmacy. 2nd ed. Philadelphia; Lea & Febiger 1986, pp.412-429.
[6] J W. J. Lin and T. L. Wu, Modification of the initial release of a highly water soluble drug from Ethylcellulose microspheres, Journal of Microencapsulation; 1999, 16: 639-644.
[7] R. W. Mendes and S. B. Roy, tabletting excipients. Part 11. Pharm Technlo, 1978, 3-63.
[8] R. N. Saha, C. Sajeev, and Sahoo J, A comparative study of controlled release matrix tablets of Diclofenac sodium, Ciprofloxacin hydrochloride and Theophylline. Drug delivery; 2001, 8: 149-154.
[9] C. Sajeev, R. Pravin, D. Jadhav, K. Ravishankar and R. N. Saha, Determination of DFS in pharmaceutical formulations by UV spectrophotometry and liquid chromatography. Analytica Chimica Acta; 2002, (463): 207-217.
[10] J S. P. Sanghvi and J. G. Nairn, Phase diagram studies for Microencapsulation of pharmaceuticals using cellulose trimellitate. J Pharm Sci; 1991, 80 (4):349-8.
[11] M. Saravanan, K. Bhaskar, R. G. Srinivasa and M. D. Dhanaraju, Ibuprofen loaded Ethylcellulose /polystyrene microspheres. Approaches to get prolong drug release with reduce burst effect and low Ethylcellulose contents. J Microencapsul; 2003, (20): 289-302.
[12] B. Simon, Microencapsulation: Methods and Industrial Application, Second Edition, Chapter 4 Microencapsulation Techniques for Parenteral Depot Systems and T heir Application in the Pharmaceutical Industry, authors, Claudia Packhauser Nina Seidel , Julia Schnieders , Thomas Kissel , and Sascha Maretschek, 2006, 99-122 ISBN: 978-0- 8247-2317-0
[13] K. D. Sudip, In-Vitro dissolution profile of the theophylline loaded Ethylcellulose microsphers prepared by emulsification solvent evaporation. Drug Development and Industrial Pharmacy; 1991, 17: 2521-2528.
[14] S. J. Svinsson, and Kristmunsdottir, Naproxen Microcapsules: Preparation and In-Vitro characterization. Int J Pharm, 1992, (82):129- 33.
[15] The British pharmacopoeia, (2004) Vol. I; 861-862
[16] C. Zinutti, F. Kedzierewicz, M. Hoffman, and P. Mancent, Preparation and characterization of Ethylcellulose microspheres containing 5- fluorouracil. Journal of Microencapsulation; 1994, 11: 555-563.