The efficacy of Elliotts B® solution as a diluent for intrathecal administration of methotrexate sodium and cytarabine is based on its buffering capacity which helps adjust the pH of these agents. In addition, data demonstrate that methotrexate sodium and cytarabine are stable in Elliotts B Solution for at least 10 hours at 25° C. No precipitation was observed.

¹Craddock et al at NCI showed that when physiologic saline was used to dilute methotrexate, the pH of the solution was as high as 8.5. When used to dilute cytarabine, the pH of the resulting solution was an unphysiological 5.3. On the other hand, when either was diluted in Elliotts B Solution, the pH was held in the more physiologic range of 7.3-7.8.2 Geiser et al found a significant decrease in chemical arachnoiditis if methotrexate was diluted in Elliotts B Solution and compared to saline: 13% to 61%.3 As a result of that study, NCI made Elliotts B Solution available to pediatric cooperative cancer study groups and major cancer centers where it is estimated that more than 95% of all children with leukemia were treated on NCI protocols between 1975 and 1992.

² Zhang et al. Physical and Chemical Stability of Methotrexate Sodium, Cytarabine and Hydrocortisone Sodium Succinate in Elliott’s B Solution. Hospital Pharmacy, 1996, Vol 31(8).

³ Craddock JC, et al. Evaluation of Some Pharmaceutical Aspects of Intrathecal Methotrexate Sodium, Cytarabine and Hydrocortisone Sodium Succinate. American Journal of Hospital Pharmacy, 1978, Vol 35(4):402-406.

⁴ Geiser CF, et al. Adverse Effects of Intrathecal Methotrexate in Children with Acute Leukemia in Remission. Blood, 1975, Vol 45(2):189-195.