Source: Pacira Pharmaceuticals.

What: After reporting a nearly 20% increase in top line sales and a 200% increase in net income, shares in Pacira Pharmaceuticals (NASDAQ:PCRX) jumped by 19.4% today.

So what: Thanks to rising use of its flagship drug, Exparel, a time-release pain medication that's used during surgical procedures, Pacira Pharmaceuticals delivered sales of $62.2 million during the third quarter, up from $52 million in Q3 2014.

Net product sales of Exparel totaled $59.7 million in the quarter, up from $50.2 million in the third quarter of 2014, and despite increased marketing efforts, that performance outpaced the company's $57.1 million in operating expenses, leading to non-GAAP earnings per share of $0.35, up from $0.16 last year. Ahead of the third-quarter results, analysts were looking for the company to report non-GAAP EPS of $0.15.

Now what: The company expects to spend at least $135 million on R&D and operations this year, but Exparel's solid sales growth has industry watchers thinking that Pacira Pharmaceuticals will be able to deliver significant bottom-line upside this year and next year.

Previously, analysts were modeling for Pacira Pharmaceuticals to deliver EPS of $0.82 in 2015 and $1.42 in 2016, but those estimates may increase following the company's better-than-hoped-for Q3 earnings and if so, then investors may want to add Pacira Pharmaceuticals to a watch list with a goal of picking up shares on a pullback.

Although Pacira Pharmaceuticals isn't an overly cheap stock (its forward P/E ratio is 34.5), an argument could be made that it's priced reasonably to its future growth opportunity because its P/E-to-growth ratio, or PEG ratio, is just 0.66. If analysts increase their forward estimates, then Pacira Pharmaceuticals could become even more attractive, especially if the company can deliver on plans to expand Exparel's use.