An adaptor configured to couple with a sealed vial, the adaptor comprising: a connector interface; an access channel in fluid communication with the connector interface; a regulator assembly comprising: a first regulator inlet in fluid communication with an ambient environment surrounding the adaptor; a first regulator lumen; a second regulator inlet in fluid communication with the ambient environment; a second regulator lumen; a first filter capable of fluid communication with the first regulator lumen and configured to filter fluid passing into the first regulator lumen, the first filter positioned in a plug portion of a regulator cap configured to be inserted into the first regulator lumen; a second filter in fluid communication with the second regulator lumen and configured to filter fluid passing from the second regulator lumen and into the ambient environment; a regulator valve in fluid communication with the first regulator lumen, the regulator valve configured to permit passage of fluid from the ambient environment into the first regulator lumen, the regulator valve further configured to prevent passage of fluid from within the vial to the first filter, the regulator valve comprising a valve stem and a flap portion; a valve seat comprising a seat aperture configured to receive at least a portion of the valve stem, the valve seat comprising a mating portion configured to engage with the plug portion; a piercing member comprising a proximal end and a distal end, the distal end comprising a piercing tip; and a regulator channel positioned at least partially within the piercing member and comprising a first regulator channel opening in fluid communication with the first regulator lumen. a connector interface; an access channel in fluid communication with the connector interface; a regulator assembly comprising: a first regulator inlet in fluid communication with an ambient environment surrounding the adaptor; a first regulator lumen; a second regulator inlet in fluid communication with the ambient environment; a second regulator lumen; a first filter capable of fluid communication with the first regulator lumen and configured to filter fluid passing into the first regulator lumen, the first filter positioned in a plug portion of a regulator cap configured to be inserted into the first regulator lumen; a second filter in fluid communication with the second regulator lumen and configured to filter fluid passing from the second regulator lumen and into the ambient environment; a regulator valve in fluid communication with the first regulator lumen, the regulator valve configured to permit passage of fluid from the ambient environment into the first regulator lumen, the regulator valve further configured to prevent passage of fluid from within the vial to the first filter, the regulator valve comprising a valve stem and a flap portion; a valve seat comprising a seat aperture configured to receive at least a portion of the valve stem, the valve seat comprising a mating portion configured to engage with the plug portion; a first regulator inlet in fluid communication with an ambient environment surrounding the adaptor; a first regulator lumen; a second regulator inlet in fluid communication with the ambient environment; a second regulator lumen; a first filter capable of fluid communication with the first regulator lumen and configured to filter fluid passing into the first regulator lumen, the first filter positioned in a plug portion of a regulator cap configured to be inserted into the first regulator lumen; a second filter in fluid communication with the second regulator lumen and configured to filter fluid passing from the second regulator lumen and into the ambient environment; a regulator valve in fluid communication with the first regulator lumen, the regulator valve configured to permit passage of fluid from the ambient environment into the first regulator lumen, the regulator valve further configured to prevent passage of fluid from within the vial to the first filter, the regulator valve comprising a valve stem and a flap portion; a valve seat comprising a seat aperture configured to receive at least a portion of the valve stem, the valve seat comprising a mating portion configured to engage with the plug portion; a piercing member comprising a proximal end and a distal end, the distal end comprising a piercing tip; and a regulator channel positioned at least partially within the piercing member and comprising a first regulator channel opening in fluid communication with the first regulator lumen.