Nazar Muhammad Ranjha1,
Asadullah Asadullah Madni2 ,
Abdullah Abu Bakar1,
Nuzhat Talib1,
Saeed Ahmad2,
Hassan Ahmad2
1Department of Pharmacy, Bahauddin Zakariya University, 60800-Multan;
2Department of Pharmacy, The Islamia University of Bahawalpur, 63100-Pakistan.
For correspondence:- Asadullah Asadullah Madni
Email: asadpharmacist@hotmail.com
Received: 5 April 2014
Accepted: 14 October 2014
Published: 15 December 2014
Citation:
Ranjha NM, Asadullah Madni A, Bakar AA, Talib N, Ahmad S, Ahmad H.
Preparation and Characterization of Isosorbide Mononitrate Hydrogels Obtained by Free-Radical Polymerization for Site-Specific Delivery. Trop J Pharm Res 2014; 13(12):1979-1985
doi:
10.4314/tjpr.v13i12.4
© 2014 The authors.
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Abstract
Purpose:To prepare and characterize acrylic acid and ethyl cellulose hydrogels of isosorbide mononitrate for site-specific delivery.
Methods:Free radical polymerization method was employed using benzoyl peroxide as initiator and N, N-Methylenebisacrylamide (MBA) crosslinked copolymer of ethyl cellulose and acrylic acid. Benzyl peroxide and N, N-Methylenebisacrylamide in varying amounts were dissolved in acrylic acid. The two solutions were mixed together to a final weight of 100 g. Hydrogels were evaluated for sol-gel characteristics, diffusion coefficient, and porosity. Hydrogel formation was examined by FTIR while drug loading efficiency study was carried out using 1 % (w/v) drug solution.
Results:Swelling and drug release decreased with increasing acrylic acid and MBA concentrations due to high degree of crosslinking. Increasing acrylic acid content of hydrogel produced a decrease in drug release from 29.89 to 25.79 %, 75.37 to 67.87 % and 84.91 to 75.85 % at pH 1.2, 6.5 and 7.5, respectively. Remarkably, high swelling was observed at higher pH. Gel fraction and porosity results showed that acrylic acid and crosslinker raised gel fraction but reduced porosity, while ethyl cellulose exhibited a reverse effect. FTIR confirmed graft copolymer formation.
Conclusion:Isosorbide mononitrate hydrogels prepared with crosslinked copolymer of ethyl cellulose and acrylic acid can be suitably formulated for targeted delivery of the drug to the small intestine.
Keywords: N, N-Methylenebisacrylamide, Ethyl cellulose, Acrylic acid, Isosorbide mononitrate, Free radical polymerization, Graft copolymer, Site-specific delive