A bottle having a sterility seal and a method for producing same are disclosed. The bottle, which can be configured to retain a medicament in powder or tablet form, features a protective cap configured to engage a transfer assembly associated with the bottle. The cap includes one or more raised ridges on an interior surface engageable with a portion of the transfer assembly. A band or layer configuration of a sealing material such as silicone is applied to the transfer assembly prior to insertion of the cap thereover. As the cap comes into surface contact with the sealing material, the ridges cause the material to "roll up" into a toroidal O-ring configuration, thereby forming a seal between the cap and the bottle adapted to the dimensional variations of those components. The seal, which is resilient, is able to withstand harsh handling treatment and pressure or temperature variations without separation from the cap or bottle, thereby providing a hermetic seal isolating the transfer assembly and, hence, the medicament from the outside environment.