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.

NuPathe Inc. (PATH) is bettering its rating of C (“hold”) from last week to a B (“buy”) this week. 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.

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

Impax Laboratories, Inc. (IPXL) shows solid improvement this week. The company’s rating rises from a C to a B. 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.

Mylan (MYL) gets a higher grade this week, advancing from a B last week to an A. Mylan is a global generic and specialty pharmaceuticals company. 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.