Of the total imports of APIs and intermediates into India, China accounts for 65-70 per cent, it added.
The situation is more alarming in case of intermediates of stages prior to APIs and key starting materials (KSMs) which are the building blocks for drugs, wherein, in some cases, China is the exclusive supplier, the rating agency said.
For instance, PenG and 7ACA, the key raw materials required for manufacturing cephalosporins are manufactured exclusively in China, it added.
Additionally, for some input materials, even if alternate sources are available, China remains the preferred source given the economical rates, Icra said.
"The outbreak of the coronavirus in China and the consequent lockout in parts of China have resulted in a shutdown of production units in China. Though majority of the pharmaceutical manufacturing facilities in China are located far away from the coronavirus affected sites, there has been a disruption in the supply chain due to the lockouts," Icra noted.
According to Icra research, domestic API manufacturers have an inventory of one-two months, which should adequately support their production till mid-March 2020.
Continuation of the virus outbreak, however, beyond mid-March 2020 may adversely impact production of these API manufacturers, possibly leading to a complete halt of production for some smaller players, Icra said.
"Alternatively, for certain intermediates, they may source it from other countries, but at higher prices. This will impact their profitability as they may not be able to fully pass on the same to the formulations manufacturers," it added.
Furthermore, while they can shift their source of supply of raw materials for exports to regulated markets like the US, it requires refiling the drug master file (DMF) with the United States Food and Drug Administration (USFDA) for approval, which takes about six months.
"In view of the above, Icra has revised its outlook on the Indian pharmaceutical industry to negative," the rating agency said.
The extent of impact of production shutdowns and increase in prices of raw materials on the profitability of the domestic pharmaceutical manufacturers would, however, vary depending on each company's product and raw material sourcing mix and the quantum of inventory held, it added.