With dozens of rescue cats to take care of, I am always looking for more economical ways to address feline health and happiness issues. I purchased Sentry PurrScriptions Plus because its formula was similar to another product that I knew was effective in controlling fleas, yet the price of Sentry was considerably less. I've found the Sentry product to be an effective and more economical way to eliminate fleas on my cats. In addition, the "quick drying formula", as stated on the box, was a pleasant surprise. Unlike some other topical liquid flea-control products, Sentry PurrScriptions Plus did not leave the cats' coats soaked in a greasy mess for days. It did not spread much beyond the application site and seemingly dried within hours.