This week, five pharmaceutical stocks are improving their overall rating on Portfolio Grader. Each of these rates an “A” (“strong buy”) or “B” overall (“buy”).

NuPathe Inc. (PATH) ups its rating to a B (“buy”) this week after earning a C (“hold”) in the week before. 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 is a strong week for Tetraphase Pharmaceuticals, Inc. (TTPH). The company’s rating climbs to B from the previous week’s C. For more information, get Portfolio Grader’s complete analysis of TTPH 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.

This week, Impax Laboratories, Inc. (IPXL) pushes up from a C to a B rating. 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) boosts its rating from a B to an A this week. 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.