Percutaneous absorption of chlorquinaldol (Sterosan)

Area of Science:

• Dermatology
• Pharmacokinetics
• Drug Metabolism

Background:

• Chlorquinaldol is an active pharmaceutical ingredient used in topical preparations for skin conditions.
• Understanding the percutaneous absorption of chlorquinaldol is crucial for assessing its efficacy and safety.
• Systemic absorption can lead to potential side effects, necessitating careful evaluation of topical formulations.

Purpose of the Study:

• To quantify the percutaneous absorption of chlorquinaldol from three distinct topical formulations.
• To compare the extent of topical absorption with that of an equivalent oral dose.
• To analyze the urinary excretion products of chlorquinaldol following topical and oral administration.

Main Methods:

• Three healthy volunteers participated in a four-period change-over study.
• Topical preparations (Sterosan-hydrocortisone ointment and cream, Sterosan ointment) were applied under occlusive dressings.
• Cumulative urinary excretion of chlorquinaldol was measured to determine absorption, with blood concentrations monitored.

Main Results:

• Percutaneous absorption varied among the topical preparations, ranging from 4.2% to 23.5% of the applied dose.
• Oral administration resulted in significantly higher absorption, with 67.6% of the dose excreted in urine.
• Blood concentrations of chlorquinaldol remained below the detection limit (<0.02 microgram/ml) after topical application.
• Urinary excretion products were similar for both topical and oral routes, primarily consisting of unchanged chlorquinaldol and its sulfate conjugate.

Conclusions:

• Percutaneous absorption of chlorquinaldol from the tested topical formulations is limited.
• The extent of absorption is considerably lower compared to oral administration.
• Topical application of chlorquinaldol, under the conditions studied, results in minimal systemic exposure.