ORIGINAL ARTICLE |
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Year : 2010 | Volume
: 58
| Issue : 6 | Page : 477-481 |
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Stimuli-sensitive hydrogels: A novel ophthalmic drug delivery system
Vinod Singh1, SS Bushetti2, Raju Appala3, Adil Shareef2, Syed S Imam2, Mamta Singh1
1 Department of Pharmaceutics & Pharmacology, SBS PG Institute of Biomedical Sciences and Research, Dehradun, Uttarakhand, India 2 Department of Pharmaceutics, Luqman College of Pharmacy, Gulbarga, Karnataka, India 3 Department of Pharmaceutical Chemistry, HKE's College of Pharmacy, Gulbarga, Karnataka, India
Correspondence Address:
Vinod Singh Department of Pharmaceutics, SBS PG Institute of Biomedical Sciences and Research, Balawala, Dehradun, Uttrakhand India
Source of Support: None, Conflict of Interest: None | Check |
DOI: 10.4103/0301-4738.71677
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Background: Stimuli-sensitive hydrogels are three-dimensional, hydrophilic, polymeric networks capable of imbibing large amounts of water or biological fluids on stimulation, such as pH, temperature and ionic change. Aim: To develop hydrogels that are sensitive to stimuli, i.e. pH, in the cul-de-sac of the eye for providing a prolonged effect and increased bioavailability with reduction in frequency of administration. Materials and Methods: Hydrogels were formulated by using timolol maleate as the model drug, polyacrylic acid as the gelling agents, hydroxyl ethyl cellulose as the viscolizer and sodium chloride as the isotonic agent. Stirring of ingredients in pH 4 phosphate buffer at high speed was carried out. The dynamic dialysis technique was used for drug release studies. In vivo study for reduction in intraocular pressure was carried out by using albino rabbits. Statistical Analysis: Drug release studies data were used for statistical analysis in first-order plots, Higuchi plots and Peppas exponential plots. Student t-test was performed for in vivo study. Results: Viscosity of the hydrogel increases from 3.84 cps to 9.54 cps due to change in pH 4 to pH 7.4. The slope value of the Peppas equation was found to be 0.3081, 0.3743 and 0.2964. Up to 80% of drug was released in an 8 h drug release study. Sterile hydrogels with no ocular irritation were obtained. Conclusions: Hydrogels show increase in viscosity due to change in pH. Hydrogels were therapeutically effacious, stable, non-irritant and showed Fickian diffusion. In vivo results clearly show a prolonged reduction in intraocular pressure, which was helpful for reduction in the frequency of administration. |
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