The grades of four pharmaceutical stocks are better this week, according to the Portfolio Grader database. Every one of these stocks has an “A” (“strong buy”) or “B” overall (“buy”) rating.

This week, NuPathe Inc. (PATH) is showing significant improvement as the company’s rating hops from a C (“hold”) to a B (“buy”). NuPathe develops pharmaceutical products used for the treatment and management of neurological and psychiatric diseases. In Portfolio Grader’s specific subcategories of Earnings Momentum and Earnings Revisions, PATH also gets A’s. For more information, get Portfolio Grader’s complete analysis of PATH stock.

Watson Pharmaceuticals (WPI) is progressing from last week’s rating of B (“buy”) as the company improves to an A (“strong buy”) this week. Watson develops, manufactures, markets, sells and distributes pharmaceutical products. For more information, get Portfolio Grader’s complete analysis of WPI stock.

Impax Laboratories, Inc.’s (IPXL) ratings are looking better this week, moving up to a B from last week’s C. Impax Laboratories develops, manufactures, and markets both proprietary and multi-source pharmaceutical products utilizing its drug delivery technologies. For more information, get Portfolio Grader’s complete analysis of IPXL stock.

This week, Mylan (MYL) pushes up from a B to an A rating. Mylan is a global generic and specialty pharmaceuticals company. Shares of the stock have been changing hands at an unusually rapid pace, up 426% from the week prior. For more information, get Portfolio Grader’s complete analysis of MYL stock.

Louis Navellier’s proprietary Portfolio Grader stock ranking system assesses roughly 5,000 companies every week based on a number of fundamental and quantitative measures. Stocks are given a letter grade based on their results — with A being “strong buy,” and F being “strong sell.” Explore the tool here.