Neutron activation of NDDP, a liposomal platinum antitumor agent.
Cis-bis-neodecanoato-trans-R,R-1,2-diamminocyclohexane platinum (II) [NDDP] is a liposome-entrapped platinum compound currently, in phase II clinical trials, that has been shown to undergo intraliposomal activation. The objective of this study was to determine the feasibility of activating NDDP and using the induced radioactivity to monitor NDDP distribution and penetration.


METHODS
Neutron activation analysis (NAA) was done on NDDP using the nuclear reactor at Texas A & M University, College Station, Texas. After a 3-hour irradiation, the NDDP samples were analyzed using an HPGE (high purity germanium) detector to determine the activation of the radioisotopic platinum. This was followed by HPLC-UV analysis to determine the stability of NDDP after exposure to the reactor's core.


RESULTS
Platinum radioisotopes were produced along with potassium-40 and sodium-24. Irradiation did not result in any significant degradation of NDDP.


CONCLUSIONS
(1) Irradiating fully synthesized NDDP is feasible for diagnostic use if a purification step is taken after the irradiation, and (2) radiation exposure is lessened by irradiating NDDP after synthesis rather than starting with high-specific-activity isotopes.
MacLean
D S
DS
Department of Thoracic/Head and Neck Medical Oncology, University of Texas M.D. Anderson Cancer Center, Houston, USA.
Khokhar
A R
AR
Perez-Soler
R
R
D000970:Antineoplastic Agents / Q000737:chemistry*; D004355:Drug Stability; D009501:Neutron Activation Analysis; D009944:Organoplatinum Compounds / Q000737:chemistry*
D000970:Antineoplastic Agents; D009944:Organoplatinum Compounds; C054367:bis-neodecanoato-1,2-diaminocyclohexaneplatinum(II)