The subject merchandise, Sorbitol Sterile Solution, is described as a growth medium for injection that contains no active biological ingredients. It consists of sorbitol, sucrose, phosphates, NZ amine or casein peptone type s, phenol red, and deionized water q.s. to 1000 ml. According to the literature, this type of product will be used as a growth medium/stabilizer in the formulation of live and live-attenuated virus vaccines.
[1] Please importantly note that only the relevant portion of the related is displayed above. You may refer to the said customs ruling for the entire ruling explanation.
[1]. https://rulings.cbp.gov/ruling/N076899