This article reports the development and preparation of an artificial cerebrospinal solution (CSF-19), which is a spinal fluid-like in-hospital formulation that has been prepared in the pharmacy at Keio University Hospital for 28 years since 1979. CSF-19 is an irrigation solution used for retaining the moisture of the brain tissue during open neurosurgeries. CSF-19 is similar to spinal fluid regarding electrolyte composition, pH and osmolarity, and the efficacy and safety of CSF-19 have been confirmed in clinical experiences of 28 years. Approximately 270 bottles (each 500 mL) of CSF-19 solution are prepared from 1 batch and 7 or 8 batches are produced per year. Two days are necessary for 1 batch production and total work time required for the whole processes from preparing premix solutions to labeling is 31.4 hours·person. Although the material cost is only 276 yen/bottle, the total production cost includes materials, personnel, depreciation and maintenance for autoclaves and clean room, quality testing, disposable materials and containers. However, this production cost of in-hospital preparation is not fully covered by the national health insurance. Therefore, a commercially available formulation of CSF-19 is expected to replace the in-hospital formulation.