Site looks professional, although the first thing that hit me was the amount of information on the homepage. I would consider placing the 'Branded Categories' column and 'Generic Categories' column on their own seperate pages and then putting two new links in the 'Search' table to these two individual pages. I would then increase the width of the 'Featured Products' table to 100% page width.
Also, on the 'Best Sellers' area at the bottom of the page, I would link the drugs to their detailed info pages and also insert a 'Buy Now' column into that table for repeat customers.
Just my thoughs! Please would you check my site too...