It isn't illegal to chew gum, but it is illegal to bring them into Singapore or sell them except for medical purposes. Since you can't buy gum (selling is illegal) there's no way to chew them so it's almost as good as not being able to chew gum. See this: http://www.customs.gov.sg/leftNa...
Definition: In Vitro. A study done in vitro, in contrast, looks at how a drug or procedure responds in the confines of a test tube or laboratory dish. Clinical trials or medical studies may be performed either in vivo or in vitro.
Protein binding in vitro.Although there is no standard method for PB measurements in vitro, equilibrium dialysis (ED) is often regarded as the âreference methodâ for determining the PB profile of a drug (78, 89). ED is relatively labor-intensive but is also quite precise (90, 107, 115).