BEIJING - China's drug watchdog has found 12 percent of traditional Chinese medicine (TCM) materials and tablets in a random sample check to be substandard, saying the quality situation is "not optimistic."

Irregularities including artificial coloring, weight-increasing practices and contamination by counterfeit or substandard ingredients were found in 93 out of 772 batches of TCM materials and tablets, according to a statement released Tuesday by the China Food and Drug Administration (CFDA).

New prescriptions in the works for TCM

Sold by weight and mostly processed from plants and animals parts, TCM ingredients are often altered through deceptive practices such as soaking them in salt water to increase their weight and mixing them with cheap but similar materials.

The statement noted that the products checked were randomly collected from TCM manufacturers, sellers and users across the country, adding that groups related to questionable products will be punished by local drug administrations.

The statement didn't name specific groups involved.

The CFDA vowed to strengthen quality supervision of TCM products and severely crack down on illegal fraud that harms the interests of consumers and drug safety.