Assessment of topical corticosteroid preparations: the human skin-blanching assay
- Authors: Haigh, John M , Kanfer, Isadore
- Date: 1984
- Language: English
- Type: text , Article
- Identifier: vital:6374 , http://hdl.handle.net/10962/d1006284
- Description: (From the introduction) Since the introduction of topical corticosteroid formulations, their use has become widespread, being prescribed for a large variety of dermatological conditions. This widespread use has created a need for a reliable method of assessing the various dosage forms of these compounds. Clinical trials are laborious, costly and difficult to mount as well as being impractical for the screening of large numbers of drugs. Patients suffering from dermatological complaints are not ideal subjects for the testing of topical corticosteroid preparations as it is difficult to obtain standardized lesions which are necessary for the comparison of results between patients (Baker and Sattar, 1968). For these reasons a number of methods have been developed for the screening of novel corticosteroids and testing of topical corticosteroid formulations.
- Full Text:
- Date Issued: 1984
Rapid UPLC - MS/MS method for the determination of ketoprofen in human dermal microdialysis samples
- Authors: Tettey-Amlalo, Ralph N O , Kanfer, Isadore
- Date: 2009
- Language: English
- Type: text , Article
- Identifier: vital:6444 , http://hdl.handle.net/10962/d1006631
- Description: Dermal microdialysis (DMD) is a technique capable of determining the percutaneous penetration of drugs from topical formulations intended for local and/or regional activity. Typically, the concentrations of drug collected in dialysates are very low, generally in the ng/ml or even pg/ml range. An additional challenge is the very low volume of sample collected at each collection time and which can range from 1 to 30 μl only. Hence the objective was to develop and validate a rapid, accurate, precise, reproducible and highly sensitive LC–MS/MS method for the quantitative analysis of ketoprofen (KET) in dialystes following application of a topical gel product to the skin of human subjects. UPLC–MS/MS was used and KET was separated on an Acquity™ UPLC BEH C18 column (100 mm × 2.1 mm i.d., 1.7 μm) and analysed in negative-ion (NI) electrospray ionisation (ESI) mode. The mobile phase (MP) consisted of acetonitrile:methanol:water (60:20:20, v/v/v) under isocratic conditions at a flow rate of 0.3 ml/min. Samples were extracted using ethyl acetate with ibuprofen (IBU) as internal standard (IS) and the organic solvent was then evaporated to dryness and the residue re-constituted in methanol. 5 μl samples were injected and analysis was performed at ambient temperature 22 ± 0.5 °C. KET and IBU eluted at 1.07 and 1.49 min, respectively. KET and IBU responses were optimised at the transitions 253.00 > 209.00 and 205.00 > 161.00, respectively. Calibration curves were linear over the range 0.5–500 ng/ml with correlation coefficients > 0.999. The accuracy and precision of the method were found to be between 99.97% and 104.67% (R.S.D. < 2%) and the mean recovery of KET from normal saline was 88.03 ± 0.3% (R.S.D. < 2.20%). The LLOQ and LOD values were found to be 0.5 and 0.1 ng/ml respectively whereas the ULOD was set at 500 ng/ml. The method was successfully applied to determine the bioavailability of KET following application of topical KET gel, Fastum® gel, to the skin of human volunteers.
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- Date Issued: 2009