Indian pharmaceutical companies must meet new manufacturing standards this year, according to a government notification released on Saturday, although small companies have asked for a delay, citing their debt load.

Jolted by a string of overseas deaths linked to Indian-made drugs since 2022, Prime Minister Narendra Modi's government has stepped up scrutiny of pharmaceutical factories to clean up the image of the $50 billion industry.

"The manufacturer must assume responsibility for the quality of the pharmaceutical products to ensure that they are fit for their intended use, comply with the requirements of the licence and do not place patients at risk due to inadequate safety, quality or efficacy," said the notification, dated Dec. 28.

Companies must market a finished product only after getting "satisfactory results" on tests of the ingredients and retain a sufficient quantity of the samples of intermediate and final products to allow repeated testing or verification of a batch, it says.

The health ministry said in August that inspections of 162 drug factories since December 2022 found an "absence of testing of incoming raw materials". It said fewer than a quarter of India's 8,500 small drug factories met international drug manufacturing standards set by the World Health Organization (WHO).

The notification said those concerns must be addressed by large drugmakers within six months and small manufacturers in 12 months. Small companies had asked for the deadline to be extended, warning that investments required to meet the standards would shut down nearly half of them because they are already heavily indebted.

The WHO and other health authorities have linked Indian cough syrups to the deaths of at least 141 children in Gambia, Uzbekistan and Cameroon.