Extended Release of Timolol from Ethyl Cellulose Microparticles Laden Hydrogel Contact Lenses

Furqan A. Maulvi1, *, Tejal G. Soni2, Dinesh O. Shah3, 4, 5
1 Maliba Pharmacy College, Uka Tarsadia University, Surat 394350, India;
2 Faculty of Pharmacy, Dharmsinh Desai University, Nadiad 387001, India;
3 Shah-Schulman Center for Surface Science and Nanotechnology, Dharmsinh Desai University, Nadiad 387001, India;
4 Department of Chemical Engineering and Department of Anesthesiology, University of Florida, Gainesville, FL 32611, United States;
5 Department of Chemical Engineering and Department of Anesthesiology, University of Florida, Gainesville, FL 32611, United States;

Article Metrics

CrossRef Citations:
Total Statistics:

Full-Text HTML Views: 3150
Abstract HTML Views: 1549
PDF Downloads: 219
Total Views/Downloads: 5033
Unique Statistics:

Full-Text HTML Views: 1458
Abstract HTML Views: 748
PDF Downloads: 146
Total Views/Downloads: 2433

© Maulvi et al; Licensee Bentham Open.

open-access license: This is an open access article licensed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.

* Address correspondence to this author at the Maliba Pharmacy College, Uka Tarsadia University, Bardoli – Mahuva Road, Tarsadi, Dist. Surat 394350, Gujarat, India; Tel: +91 8238651055; Fax: +91 02625 255882; E-mail:


Glaucoma is a second leading cause of blindness globally after cataract, which is managed through eye drops, which are highly inefficient due to a low bioavailability of less than 1-5%. Frequent administration of eye drops leads to incompliance in patients, so there is a great need for medical device such as contact lenses to treat glaucoma. The objective of research was to provide sustained ocular delivery of timolol via prototype poly (hydroxyethyl methacrylate) hydrogel contact lenses which may improve bioavailability due to increase in ocular residence time of drug. The present work was to encapsulate drug in ethylcellulose microparticles, and to entrap these microparticles in the hydrogel. Microparticles were prepared by spray drying method using different ratios of drug to ethylcellulose. The solid state characterization studies of drug loaded microparticles revealed the transformation of drug to an amorphous state. The hydrogels were characterized by studying their optical and physical properties to determine their suitability as extended wear contact lenses. Microparticles laden hydrogels were compared with direct drug loaded hydrogels. The study of microparticles laden hydrogels showed reduction in optical and physical properties and the impact was proportional to the amount of microparticles in hydrogels. The results suggest the application of optimization and nanotechnology. In vitro drug release study revealed that direct loading batch delivers drug for 22 hours with high drug loading of 150 µg, while microparticles laden hydrogel deliver drug up to 48 hours (zero order kinetics) with low drug loading of 50 µg. The hydrogels appeared safe in the cytotoxicity study. The study demonstrated the promising potential of loading the ethyl cellulose microparticles into hydrogels to serve as a good platform for sustained ophthalmic drug delivery.

Keywords: Cytotoxicity, hydrogel contact lenses, spray drying, sustained drug delivery, timolol.