Determination of transdermal sildenafil in nude mouse skin by reversed-phase high-performance liquid chromatography.
A simple and sensitive high-performance liquid chromatographic method was developed for the determination of sildenafil transdermal permeation of nude mouse skin. A reversed-phase column with UV detection at 224 nm was used for chromatographic separation. The mobile phase consisted of 32% acetonitrile with 0.2% phosphoric acid in water at pH 5.3 adjusted with 10 M NaOH with the flow-rate set at 1.0 ml/min. The limit of quantitation achieved was 5 ng/ml, and the calibration curve showed good linearity over the concentration range of 5-500 ng/ml. The relative standard deviations of within- and between-day analyses were all within 15%. Sildenafil was found to be stable between pH 3 and 12 during 24-h incubation with skin. After transdermal administration of 15.8 microg/ml of sildenafil to nude mouse skin, it was detected as early as 15 min. The transport amount of sildenafil could be quantitated and, at pH 8-11, had the highest permeation rate in nude mouse skin.
Lia
J
J
Department of Pharmaceutics, School of Pharmacy, Taipei Medical University, Taiwan. jhorng@tmu.edu.tw
Chang
T W
TW
D000279:Administration, Cutaneous; D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D051379:Mice; D008819:Mice, Nude; D010726:Phosphodiesterase Inhibitors / Q000008:administration & dosage / Q000378:metabolism*; D010879:Piperazines / Q000008:administration & dosage / Q000378:metabolism*; D011687:Purines; D012015:Reference Standards; D015203:Reproducibility of Results; D000068677:Sildenafil Citrate; D012867:Skin / Q000378:metabolism*; D013056:Spectrophotometry, Ultraviolet; D013450:Sulfones
D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D011687:Purines; D013450:Sulfones; D000068677:Sildenafil Citrate