BIOAVAILABILITY OF CARBACHOL CHLORIDE FROM DIFFERENT GEL FORMULATIONS

Document Type : Original Article

Authors

1 Department of Pharmaceutics, Faculty of Pharmacy, Assiut University, Assiut, Egypt

2 Department of Ophthalmology, Faculty of Medicine, Assiut University, Assiut, Egypt

Abstract

The in vitro release of carbachol chloride, a cholinomimetic drug, from different ophthalmic gel-formulations has been investigated. The release data were found to be in favour of the diffusion controlled mechanism. The effect of viscosity on the release pattern has been also studied. The amount of the drug diffused from the aqueous solution of the drug was found to decrease with an increase in the solution viscosity. On the other hand, the viscosity did not affect the release rate when the drug was formulated in gels.
The effect of different gel formulations on the drug activity, a decrease in the intraocular pressure, IOP, was studied on human patients, It was found that the incorporation of the drug into hydrophilic gels resulted in an improvement of its activity. The parameters of drug activity: area above time curve; maximum drug response and time of maximum response. The statistical analysis of the data obtained was assessed. A correlation between the in vitro and in vivo data has been deduced.