Natural pesticides company TyraTech (LON: TYR) is closing in on a fundraising round that could reach up to $4.6 million, according to securities filings.

The Morrisville company has raised $3.7 million from three investors so far.

The offering is a mix of equity, option, warrants and rights to acquire other securities.

TyraTech has developed pesticide technologies made from natural active ingredients. The products address pests insects and parasites such as lice and ticks and have applications in humans as well as livestock.

The TyraTech technology, based on discoveries at the Vanderbilt-Ingram Cancer Center, aims to address growing pesticide resistance found in pests. Most pesticides pose some health risks to humans and animals but alternatives, including natural pesticides haven’t worked well. Using natural ingredients, TyraTech has developed a natural pesticide that targets a receptor found in invertebrates. That receptor is not active in humans, so the pesticide is safe for people.

The company was founded in 2004 and had been in R&D and testing of the patented technology through 2012. TyraTech went public in 2007 on the AIM section of the London Stock Exchange. Last year, the company began a push to bring its products to market through commercialization partners, including Envance Technologies, a joint venture formed last December between TyraTech and AMVAC Chemical Corporation. The joint venture marries TyraTech’s technology with AMVAC’s global commercialization capabilities.

Also in 2012, TyraTech announced its pesticide branded as Terminix would be sold through The Home Depot. TyraTech says it has six products on the market available at The Home Depot and other outlets through the Envance partnership.

TyraTech has laid out an overseas strategy for targeting emerging markets, where insects and pests pose a significant problem.

The firm decided in 2011 to relocate its corporate headquarters and create 105 jobs in Morrisville. It received no tax incentives or grants from the state.

“One of the key drivers to make the move to the Triangle area are the educational institutions and universities, especially NC State which has very strong programs in entomology and veterinary sciences which we hope to draw upon as we expand,” the firm’s chairman said at the time.