Investors with an interest in Medical - Drugs stocks have likely encountered both Assertio (ASRT) and Pacira (PCRX). But which of these two stocks offers value investors a better bang for their buck right now? We'll need to take a closer look.There are plenty of strategies for discovering value stocks, but we have found that pairing a strong Zacks Rank with an impressive grade in the Value category of our Style Scores system produces the best returns. The proven Zacks Rank puts an emphasis on earnings estimates and estimate revisions, while our Style Scores work to identify stocks with specific traits.Assertio and Pacira are sporting Zacks Ranks of #2 (Buy) and #3 (Hold), respectively, right now. Investors should feel comfortable knowing that ASRT likely has seen a stronger improvement to its earnings outlook than PCRX has recently. But this is just one piece of the puzzle for value investors.Value investors also try to analyze a wide range of traditional figures and metrics to help determine whether a company is undervalued at its current share price levels.The Style Score Value grade factors in a variety of key fundamental metrics, including the popular P/E ratio, P/S ratio, earnings yield, cash flow per share, and a number of other key stats that are commonly used by value investors.ASRT currently has a forward P/E ratio of 1.82, while PCRX has a forward P/E of 26.63. We also note that ASRT has a PEG ratio of 0.09. This popular metric is similar to the widely-known P/E ratio, with the difference being that the PEG ratio also takes into account the company's expected earnings growth rate. PCRX currently has a PEG ratio of 0.78.Another notable valuation metric for ASRT is its P/B ratio of 0.53. The P/B ratio pits a stock's market value against its book value, which is defined as total assets minus total liabilities. For comparison, PCRX has a P/B of 4.66.Based on these metrics and many more, ASRT holds a Value grade of A, while PCRX has a Value grade of C.ASRT is currently sporting an improving earnings outlook, which makes it stick out in our Zacks Rank model. And, based on the above valuation metrics, we feel that ASRT is likely the superior value option right now.Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report ASSERTIO THERAPEUTICS, INC (ASRT): Free Stock Analysis Report Pacira Pharmaceuticals, Inc. (PCRX): Free Stock Analysis Report To read this article on Zacks.com click here.