The disclosure provides an injectable ganaxolone formulation comprising ganaxolone, sulfobutyl ether-ß-cyclodextrin； and water. The injectable ganaxolone formulation optionally includes a surfactant and a pH modifier. The ganaxolone and sulfobutyl ether-ß-cyclodextrin may be in an inclusion complex. The disclosure also provides a lyophilized powder of the ganaxolone/ sulfobutyl ether-ß-cyclodextrin formulation that may be reconstituted in water for injection. The disclosure provides a method of treating a patient having a seizure disorder, stroke, or traumatic brain injury, comprising administering an effective amount of the injectable ganaxolone formulation comprising ganaxolone, sulfobutyl ether-ß-cyclodextrin； and water. The disclosure also provides combination methods in which the injectable ganaxolone/ sulfobutyl ether-ß-cyclodextrin formulation is administered in combination with at least one additional active agent.
