Injectable compositions containing gabapentin and processes for preparing sterile injectable compositions containing gabapentin are discussed. The process includes subjecting the compositions to heat. Heating results in increased production of gabapentin lactam, which has previously been shown to be toxic. Surprisingly, heated injectable compositions containing gabapentin are found to be non-toxic when administered intrathecally. Thus, heating for the purposes of sterilization or to assure sterility provides a viable option in the production of injectable compositions containing gabapentin.