The overall ratings of 6 Pharmaceuticals stocks are down on Portfolio Grader this week. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

This week, Mallinckrodt Plc (MNK) drops from a C to a D rating. For more information, get Portfolio Grader’s complete analysis of MNK stock.

Slipping from a C to a D rating, Endo International Plc (ENDP) takes a hit this week. Endo International Plc provides specialty healthcare solutions in the United States and internationally. The company also gets F’s in earnings growth, earnings momentum, and return on equity. For more information, get Portfolio Grader’s complete analysis of ENDP stock.

This is a rough week for Paratek Pharmaceuticals Inc (PRTK). The company’s rating falls to D from the previous week’s C. The company also gets F’s in earnings revisions, return on equity, and free cash flow. For more information, get Portfolio Grader’s complete analysis of PRTK stock.

POZEN Inc. (POZN) declines this week from a C to a D. POZEN Inc. is a pharmaceutical company that develops therapeutics for diseases with unmet medical needs. The company also gets F’s in sales growth, operating margin growth, earnings growth, earnings revisions, earnings momentum, and return on equity. For more information, get Portfolio Grader’s complete analysis of POZN stock.

Aradigm Corporation (ARDM) experiences a ratings drop this week, going from last week’s D to a F. The company also gets F’s in sales growth, operating margin growth, earnings revisions, return on equity, and free cash flow. For more information, get Portfolio Grader’s complete analysis of ARDM stock.

This week, Acasti Pharma Inc. Class A’s (ACST) rating worsens to a F from the company’s D rating a week ago. Acasti Pharma Inc. Class A is a pharmaceutical company that develops drugs for cardiovascular diseases. The company also gets F’s in sales growth and earnings momentum. For more information, get Portfolio Grader’s complete analysis of ACST 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.