The World Health Organisation (WHO) that it had renewed approval for seven anti-AIDS drugs made by Indian firm Ranbaxy, almost a year after they were struck from an international list because of concerns over the reliability of laboratory tests.
Thanks to new data, the antiretroviral (ARVs) from India's top pharmaceutical group have been put back on the UN health agency's "prequalification" list, the WHO said in a statement.
Three drugs from another Indian firm, Aurobindo Pharma Ltd, have also been added to the list, which sets minimum quality standards for cheaper medication used in aid programmes.
The list is a key part of attempts to supply more affordable anti-AIDS drugs in poor countries where they are most needed.
"The addition of ten medicines will benefit existing AIDS programmes and procurement schemes," the WHO said in a statement.
"It will reinforce efforts to scale up access to ARVs in high-burden countries by increasing the choice of quality products in countries which may have only limited capacity to control and monitor medicines."
Around 6.5 million people in poor countries currently need ARV therapy, the WHO noted.
Three of the Ranbaxy medicines were taken off the WHO's list in August 2004, following concerns over "bioequivalence" tests.
Such tests are meant to prove that generic medicines have the same effect as the original branded drugs they copy.
In November 2004, Ranbaxy withdrew its four remaining anti-AIDS drugs from the list after it found discrepancies in data compiled by independent laboratories in India, which were meant to prove the drugs' effectiveness.
The seven drugs were reinstated after Ranbaxy commissioned different laboratories to do new bioequivalence tests, the WHO said.
The WHO said it also "ran the full range of quality, safety and efficacy checks on the medicines as well as thorough inspections of the new laboratories."
"The products and laboratories were all found to be satisfactory," it said.
The single international approval for generic and brand-name drugs was approved by WHO member states last year, in an effort to cut costs and speed up supply.