The steel door of the shipping container in Nigeria's Lagos port swings open to reveal hundreds of cardboard boxes packed with sachets of anti-malaria medicine.

But these pills would be of no use to someone suffering from the life-threatening condition.

The packaging may be identical to an Indian-manufactured drug which sells well in Nigeria, but when the pills were examined in a laboratory they were found to contain nothing more than chalk.

These fake drugs were produced in China and were seized by Nigeria's National Agency for Food and Drug Administration and Control (Nafdac).

The war against counterfeit medicine has been on for more than 20 years in Nigeria.

"With the crackdown on illegal narcotics, drug barons have redirected their resources to manufacturing counterfeit medical products because it is more lucrative and less risky," says Dr Paul Orhii, the director general of Nafdac.

Comprehensive surveys have not been carried out for some years, but a report by the World Health Organization in 2011 suggested the war is far from won.

It said more than two-thirds of malaria medicine in Nigeria was fake or substandard.

Now the consumers of the medicine are being armed with exactly what they need to outwit the counterfeiters.

More and more packs of medicine produced by pharmaceutical companies have a small strip added to the packaging - similar to the scratch panel people are used to seeing on a mobile phone charge-card.

"When the patient picks the medicine off the shelf they scratch the panel to reveal a unique number or code," says the Ghanaian entrepreneur Bright Simons.

"The consumer takes out a mobile phone and sends the code to a toll-free number," he explains.

Standing in a market in Lagos, the founder of the organisation mPedigree tests out the technology.

Within two seconds of texting the number from a pack of anti-malaria medicine, a message appears on his phone with the word "YES" - a simple response meaning the drug is genuine.

"This allows even illiterate people to latch on," says Mr Simons.

"If they receive the word 'NO' there will also be a local number so they can alert the authorities about this encounter with a potentially toxic or fatal chemical masquerading as medicine."

Valuable data
MPedigree is now operating in eight countries including Ghana, Kenya, Nigeria and India. Cameroon and Rwanda are next.

For the service to work, the national drug regulators, mobile phone networks and pharmaceutical companies have to come on board.

For them the technology has the potential to provide valuable data about the demand for their medicine in order to plan their distribution more efficiently and precisely.

"Imagine just-in-time deliveries of rare medicines to specialist clinics or even direct delivery of doses to chronic patients periodically," Mr Simons says.

Most of the packets of medicine with the scratch panel are currently available in hospitals to allow doctors and nurses to be sure of what they are giving patients.

But by the end of February mPedigree hopes there will be 10 million packets in pharmacies across the world.

In a $30m (£18.6m) state-of-the-art pharmaceutical factory just outside Lagos, laboratory technicians keep a close eye on digital readouts as huge steel containers mix up the ingredients for an antibiotic pill.

With Nigeria's population of about 170 million and its ambitions to become a major exporter, this is potentially an extremely lucrative business for the company May and Baker which has operated in Nigeria for 70 years.

Profits are dented by a lack of electricity, making huge diesel-thirsty generators a necessity.

The business is also threatened by the counterfeiters, so mPedigree is a welcome partner.

"I can estimate that over 20% of our top line is lost to the activities of these guys," says Nnamdi Okafor, the managing director May and Baker Nigeria PLC.

"They are very smart people. Usually they wait for you to come up with a new product," says Mr Okafor, standing next to machines which spit out two million antibiotic pills a day.

"And the moment they see that the product has got some good equity in the market, they move quickly.

"They copy everything from the physical product to the packaging and the logo," he says.

"Everything will be exact and sometimes they even come out looking better than the original product.

"It is impossible for anybody to know even for the manufacturers themselves - unless you go to the lab."

Enemies
Of course the key difference is the content of the medicine.