Samarium-153
History
1853
The element Samarium was first observed spectroscopically by the Swiss chemist Jean Charles Galissard de Marignac while he was working with a material called dydimia.
(Right) 1850s spectroscope, invented by Kirchhoff and Bunsen. Given the year, this is the spectroscope most likely used to discover samarium.
1879
Twenty-six years later, in Paris, Paul-Émile Lecoq de Boisbaudran became the first to isolate a Samarium salt.
"First, Boisbaudran extracted ‘didymium’ from the mineral samarskite and made a solution of ‘didymium’ nitrate. He then added ammonium hydroxide and found two precipitates were formed; one containing ‘didymium’ and the other a new element – samarium."
(Above) Ilmensky Mountains, Southern Ural Mountains of Russia; where samarskite was discovered.
Boisbaudran named Samarium after the mineral it had been discovered in, samarskite. Samarksite had been named in 1847 by mineralogist Gustav Rose, after the Russian mine official who gave him a sample of it: Colonel Vasili Samarsky-Bykhovets. He was the first person to have a chemical element named after him.
(Above) Cut samarskite. (Right) Gustav Rose.
1986
Samarium-153 was identified as having potential for use as a radiotherapeutic agent due to its nuclear properties, ease of synthesis and high purity yield.
(Above) University of Missouri-Columbia circa 1980s
1987
University of Missouri-Columbia developed samarium-153 EDTMP and proposed it for use in radiation treatment of tumors in humans. They proceeded with a pharmacokinetic trial in 5 patients with metastatic bone cancer, using subtherapeutic doses. The study came to the conclusion that samarium-153 ETDMP was safe and suitable for therapeutic trials.
1997
After several trials and adjustments, samarium-153 lexidronam pentasodium was cleared for use as the drug Quadramet on March 28th, 1997 by the Food and Drug Administration. Today, the final approved formulation is still in use.
2017
Starting November of last year, samarium-153 lexidronam is being studied for use in treating recurring nonmetastatic prostate cancer following radical prostatectomy. Another radiopharmaceutical, samarium-153 hydroxyapatite, is being evaluated for synovectomy in patients with hemophilic arthropathy.
(Above) Food and Drug Administration stamp, clip art.