A bypass valve apparatus for permitting mixing of at least two components within a syringe barrel having a proximal end and a distal end comprising a nozzle, the bypass valve apparatus comprising: the syringe barrel; a stopper disposed within the syringe barrel which, in an initial position, is spaced apart from the distal end of the syringe barrel, thereby defining a first chamber of the syringe barrel proximal to the stopper and a second chamber distal to the stopper, the stopper being configured for slidable liquid-tight engagement with an inner surface of the syringe barrel and comprising a proximal end, a distal end, and a fluid channel extending therebetween; a plunger slidably positioned in the syringe barrel proximal the stopper, further defining the first chamber distal to the plunger, the plunger being configured for slidable engagement with the inner surface of the syringe barrel; and a cap comprising a base and a stem, the stem comprising a distal end connected to the base, a proximal end, and a sidewall extending therebetween, wherein the cap is removeably connected to the syringe barrel and, when connected to the syringe barrel, the stem extends through the nozzle and the second chamber of the syringe barrel into the fluid channel of the stopper to form a liquid-tight seal with the fluid channel of the stopper such that fluid flow through the fluid channel between the first chamber and the second chamber of the syringe barrel is prevented wherein the cap is configured to be disconnected from the syringe barrel by sliding the proximal end of the stem through the second chamber and through the nozzle, thereby establishing fluid communication through the fluid channel of the stopper and defining a fluid flow path from the first chamber to the second chamber of the syringe barrel, and wherein, after disconnecting the cap from the syringe barrel, advancing the plunger towards the stopper causes a first component in the first chamber to pass through the fluid channel of the stopper to mix with a second component in the second chamber, and wherein, after the first component passes from the first chamber to the second chamber, the plunger is configured to advance the stopper from the initial position to a final position in which the stopper is adjacent to the distal end of the syringe barrel, thereby expelling the mixed first and second components from the second chamber through the nozzle. the syringe barrel; a stopper disposed within the syringe barrel which, in an initial position, is spaced apart from the distal end of the syringe barrel, thereby defining a first chamber of the syringe barrel proximal to the stopper and a second chamber distal to the stopper, the stopper being configured for slidable liquid-tight engagement with an inner surface of the syringe barrel and comprising a proximal end, a distal end, and a fluid channel extending therebetween; a plunger slidably positioned in the syringe barrel proximal the stopper, further defining the first chamber distal to the plunger, the plunger being configured for slidable engagement with the inner surface of the syringe barrel; and a cap comprising a base and a stem, the stem comprising a distal end connected to the base, a proximal end, and a sidewall extending therebetween, wherein the cap is removeably connected to the syringe barrel and, when connected to the syringe barrel, the stem extends through the nozzle and the second chamber of the syringe barrel into the fluid channel of the stopper to form a liquid-tight seal with the fluid channel of the stopper such that fluid flow through the fluid channel between the first chamber and the second chamber of the syringe barrel is prevented wherein the cap is configured to be disconnected from the syringe barrel by sliding the proximal end of the stem through the second chamber and through the nozzle, thereby establishing fluid communication through the fluid channel of the stopper and defining a fluid flow path from the first chamber to the second chamber of the syringe barrel, and wherein, after disconnecting the cap from the syringe barrel, advancing the plunger towards the stopper causes a first component in the first chamber to pass through the fluid channel of the stopper to mix with a second component in the second chamber, and wherein, after the first component passes from the first chamber to the second chamber, the plunger is configured to advance the stopper from the initial position to a final position in which the stopper is adjacent to the distal end of the syringe barrel, thereby expelling the mixed first and second components from the second chamber through the nozzle.