Franklin County Narcotics Enforcement Unit head Detective Jason Grellner says a pseudoephedrine product marketed as meth-resistant could put an end to clandestine labs in Missouri, even though the Drug Enforcement Administration (DEA) is questioning the product maker’s claims.

Grellner said the Zephrex-D, which uses the slogan — “Powerful Congestion Relief. Powerful Crime Protection,” makes it extremely difficult for meth makers to extract pseudoephedrine from the cold pills.

Westport Pharmaceuticals of Maryland Heights produces the drug.

The Associated Press reported that James Shroba, the DEA’s acting special agent in charge of the St. Louis office, sent Westport Pharmaceuticals a letter calling the company out on its marketing of the cold and allergy medication. He said claims that Zephrex-D is meth-resistant are wrong since DEA chemists were, in fact, able to make meth from it.

According to Grellner, it is possible, but not feasible to make meth from Zephrex-D.

He explained that the percentage of Zephrex-D that can be converted into meth is between 1/2 percent and 2 percent, compared to 72-80 percent of pills like Sudafed.

“Because it is so low, the feasibility of using the product is also low,” said Grellner. “It costs so much money and time that it is not feasible.”

Shroba wrote that the meth-resistant claims in Westport’s corporate literature and on the Zephrex-D website “are inconsistent with the results of extraction tests” conducted by DEA’s Office of Forensic Sciences. His letter stopped short of demanding that the company discontinue the marketing claims, though Shroba said he planned to make the DEA findings known to police in Missouri, according to the AP.

A Westport Pharmaceuticals spokesperson said company officials are surprised by the DEA’s stance in the letter because only very small amounts of meth can be extracted from Zephrex-D.

Company officials added that a single dose would cost $250 to $500, or 10 to 20 times the street value. She said that makes it impractical to believe meth-makers could successfully use Zephrex-D.

Grellner added that the sale of Zephrex-D could put an end to much of the meth production in Missouri.

“If it continues to be sold, it will put an end to clandestine labs that we have seen grow across the state in the last decade,” he said.

In March 2012, Westport applied for an exemption to the federal Combat Meth Act. The DEA informed Westport in December that the exemption was denied.

Last month, six Missouri congressmen urged the DEA to reconsider and allow “unrestricted access” to Zephrex-D, calling it “a huge advancement in our fight against this scourge.” It was signed by Republican Reps. Blaine Luetkemeyer, Sam Graves, Billy Long, Vicky Hartzler and Ann Wagner, and Democratic Rep. William Lacy Clay, the AP reported.

According to Westport officials, testing has proven that meth cannot be made with Zephrex-D by using the most popular way of making the drug, the so-called “one-pot” or “shake-and-bake” method in which the ingredients are mixed together in a soda bottle.

Grellner added that there has been no evidence of the use of Zephrex-D to illegally manufacture meth since the product has gone on the market.

“This product has been out since December and we haven’t found that Zephrex was used at a single meth lab site in Missouri,” he said.

“This product has given good results that it can’t be used to make meth.”