A dosing bottle is made by injection molding a synthetic resin preform with a threaded neck finish portion and a body portion. The neck finish has an internal collar adjacent said lower end thereof. The preform is removed from the injection mold and inserted into the mold of a blow molding machine. The mold has a cavity with a body portion conforming to the desired configuration and dimensions for the body of the bottle and a neck portion closely conforming to the configuration and dimensioning of the neck portion closely conforming to the configuration and dimensioning of the neck portion of the preform. The preform is heated and inserted into the blow mold cavity with the neck finish portion of the preform being sealed from the body portion of the cavity. Air is introduced into the body portion of the preform to blow the body portion of the preform into conformity with the body cavity while precluding any distortion of the collar and of the neck finish.