Authors: A.R. Fakhari, A.R. Khorrami, M. Shamsipur
A stability-indicating
high-performance thin-layer chromatography (HPTLC) method was developed and validated for simultaneous determination of steroidal hormones levonorgestrel and ethinyloestradiol both in bulk drug and in low-dosage oral contraceptives. Optimization of conditions for the spectrodensitometric procedure was reached by eluting HPTLC silica gel plates in a 10cmx10cm horizontal chamber. The solvent system consisted of
hexane-chloroform-methanol (1.0: 3.0: 0.25, v/v/v). This system was found to give compact, dense and typical peaks for both levonorgestrel (R"f=0.65+/-0.03) and ethinyloestradiol (R"f=0.43+/-0.02). Densitometric analysis of the drugs was carried out in the