Estimation of impurity profiles of drugs and related materials. Part 16: Identification of the side-products of the ethinylation step in the synthesis of contraceptive gestogens.
A new apolar impurity (3,17 alpha-diethinyl-13-ethyl-3,5-gonadiene-17-ol, IIb) was detected and identified in norgestrel with the aid of thin-layer and high-performance chromatography and spectroscopic techniques. IIb is the product of the acid-catalysed dehydration of an overethinylated side product (Ib) of the ethinylation step in the synthesis of norgestrel. IIb can be determined by thin-layer densitometry and high-performance liquid chromatography. Another impurity (17 alpha-ethinyl-13-ethyl-4-gonene-17-ol, IV), originating from a side product of the Birch reduction step in the synthesis of norgestrel was also detected and identified. The spot of IV overlaps with that of IIb in the TLC system of USP XXIII but can be separated and quantification by more selective TLC systems and by gas chromatography.
Horváth
P
P
Chemical Works of Gedeon Richter Ltd., Budapest, Hungary.
Balogh
G
G
Brlik
J
J
Csehi
A
A
Dravecz
F
F
Halmos
Z
Z
Laukó
A
A
Rényei
M
M
Varga
K
K
Görög
S
S
D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D003280:Contraceptives, Oral, Synthetic / Q000138:chemical synthesis / Q000302:isolation & purification*; D009644:Norgestrel / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000302:isolation & purification*; D045167:Progesterone Congeners / Q000138:chemical synthesis / Q000302:isolation & purification*; D013057:Spectrum Analysis
C107815:3,17-diethynyl-13-ethyl-3,5-gonadiene-17-ol; D003280:Contraceptives, Oral, Synthetic; D045167:Progesterone Congeners; C107814:3-deoxonorgestrel; D009644:Norgestrel