Advances in pharmacological strategies for the prevention of cataract development.

Cataractous-opacification of the lens is one of the leading causes of blindness in India. The situation can be managed by surgical removal of the cataractous lens. Various pharmacological strategies have been proposed for the prevention and treatment of cataract. Information on possible benefits of putative anticataract agents comes from a variety of approaches, ranging from laboratory experiments, both in vitro and in vivo , to epidemiological studies in patients. This review deals with the various mechanisms, and possible pharmacological interventions for the prevention of cataract. The article also reviews research on potential anticataractous agents, including aldose reductase inhibitors, glutathione boosters, antiglycating agents, vitamins and various drugs from indigenous sources.

Lowering of intraocular pressure by topical application of Daucus carota seed extract in rabbits.

In normotensive rabbits topical application of Daucus carota seed extract at the concentration of 0.3, 0.6 and 1.2% resulted in mean IOP reduction of 19.33. 23.20 and 25.61% respectively from baseline. As no significant difference was observed between the change in IOP in 0.6 and 1.2% extract treated groups, 0.6% concentration was chosen for further evaluation in rabbits with experimentally elevated IOP. In water loaded rabbits, maximum mean IOP reduction with 0.6% extract was 29.39%, which was comparable to pilocarpine. In steroid pretreated rabbits, maximum mean IOP reduction was 30.27% from baseline, which was significantly higher than pilocarpine. The extract showed a comparatively slower onset of action however, the duration of action was comparable to pilocarpine in all the experimental models.

In vitro percutaneous absorption of verapamil.

The in vitro percutaneous absorption of verapamil hydrochloride (VHCl) was investigated in order to assess its feasibility for transdermal development. The experiments were carried across mice and guinea pig skins using Keshary-Chien diffusion cell. The values of diffusion rate (J) and permeability coefficient (Kp) across guinea pig skin were lowered as compared to mouse skin. Increased drug concentration in donor compartment increased value of J but decreased value of Kp. Under similar conditions, values of J and Kp were lowered for dorsal skin as compared to abdominal skin, both for mice and guinea pig. The results indicate that verapamil can be administered transdermally.

Hepatoprotective studies on Phyllanthus emblica Linn. and quercetin.

Phyllanthus emblica is a constituent of many hepatoprotective formulations available in market. 50% alcoholic extract of P. emblica and quercetin isolated from it were studied for hepatoprotective effect against country made liquor (CML) and paracetamol challenge in albino rats and mice respectively. The extract at the dose of 100 mg/100 g [corrected], po and quercetin at the dose of 15 mg/100 g, po, produced significant hepatoprotection.

In vitro transdermal delivery of atenolol using mouse and guinea pig.

In vitro percutaneous absorption of atenolol was done in order to assess its feasibility for transdermal development across mouse and guinea pig skins using Keshary-Chien type of diffusion cell. Values of diffusion rate (J) and permeability coefficient (Kp) across guinea pig skin were lowered as compared to those in mouse skin. When the concentration of drug in donor compartment was increased a decrease in Kp and increase in J value were observed with both the skins. Under the same conditions, values of J and Kp were lowered for dorsal skin compared to abdominal skin both for mouse and guinea pig. The results suggest that atenolol can be pursued further for transdermal system development.