The following commentary comes from an independent investor or market observer as part of TheStreet's guest contributor program, which is separate from the company's news coverage.By Dave Sterman NEW YORK ( StreetAuthority) -- A regular scan of Securities and Exchange Commission filings by corporate insiders can point the way to great investment opportunities. These officers and directors use their own funds to snap up their company's stock on the open market. You'll often find recognizable names, underscoring bullish opinions you may already have. For example, insiders have recently acquired shares at firms such as Chesapeake Energy ( CHK), Ford Motor ( F), Whirlpool ( WHR) and Family Dollar Stores ( FDO). Yet you'll also come across companies you've never heard of, the ones that toil in anonymity until they appear on various stock screens. With this in mind, I've taken a look at several small stocks that recently saw significant insider buying and found three companies that appear to have especially strong appeal. (Special thanks to insiderinsights.com, which provides me with the insider information used in this and other insider-focused stories.) Here they are... 1. Biosante Pharmaceuticals ( BPAX) Market cap.: $273 million Three Insiders first started acquiring a collective 17,000 shares of this testosterone drug-developer back in January when shares traded under $2. Investors grew increasingly excited about the company's prospects, as several drugs moved closer to getting final Food and Drug Administration approval. Shares moved up toward the $4 mark this summer, but the sharp market drop crushed virtually every biotech stock, including Biosante. Biotech companies tend to elicit nervousness from investors, because these firms may find it harder to raise more money for their research and development efforts during a market slowdown. Undeterred, Biosante's insiders again bought a collective 117,000 shares in August at an average price of about $2.30. Just this week (Nov. 14), another insider made a modest additional purchase of 3,000 shares. Why are these insiders so enthused? Because the company's LibiGel, which among other uses, treats female sexual dysfunction, could be approved as soon as early 2012. Biosante is also partnering with Teva Pharmaceuticals ( TEVA) to secure FDA approval of a testosterone gel for the treatment of male patients with Hypogonadism, a hormone dysfunction in the sex glands. Teva, which is responsible for all regulatory and marketing activities for the drug, will go before the FDA in the middle of February. It won't be long before we see whether this bullish insider activity pays off.