Analysis of chromameter results obtained from corticosteroid-induced skin blanching. I. Manipulation of data
- Smith, Eric W, Haigh, John M, Walker, Roderick B
- Authors: Smith, Eric W , Haigh, John M , Walker, Roderick B
- Date: 1998
- Language: English
- Type: text , Article
- Identifier: vital:6424 , http://hdl.handle.net/10962/d1006559
- Description: Purpose. One of the unresolved issues in the FDA Guidance document for topical corticosteroid bioequivalence testing is the method of manipulation suggested for the chromameter data. The purpose of this study was to manipulate the instrumental data from a typical blanching study in a number of ways to investigate the appropriateness of these procedures for comparison with the subjective visually-assessed results. Methods. The human skin blanching assay methodology routinely practiced in our laboratories was utilised and the vasoconstriction produced by two corticosteroid formulations of different potency was assessed visually and instrumentally by use of a Minolta chromameter. The instrumental data were corrected for zero-time and unmedicated site readings. In addition, Euclidean distances were calculated using all data generated by the instrument. Results. Individually the a-, b- and L-scale chromameter values are imprecise and there is negligible vasoconstriction response recorded for the moderately potent formulation. Arithmetical manipulation of the data as suggested by the FDA does not appear to improve the quality of the data in any way. Euclidean distance analysis more closely resembles the visual data and appears to have better precision. Conclusions. It is clear that mathematical correction of chromameter data is unnecessary, especially since the instrumental data are extremely imprecise. Furthermore, the assessment of each individual chromameter index does not adequately characterise the blanching response profile. It is therefore suggested that Euclidean distance may be a better measure on which to base an analysis of bioequivalence than the truncated data set methodology currently suggested by the FDA.
- Full Text: false
- Authors: Smith, Eric W , Haigh, John M , Walker, Roderick B
- Date: 1998
- Language: English
- Type: text , Article
- Identifier: vital:6424 , http://hdl.handle.net/10962/d1006559
- Description: Purpose. One of the unresolved issues in the FDA Guidance document for topical corticosteroid bioequivalence testing is the method of manipulation suggested for the chromameter data. The purpose of this study was to manipulate the instrumental data from a typical blanching study in a number of ways to investigate the appropriateness of these procedures for comparison with the subjective visually-assessed results. Methods. The human skin blanching assay methodology routinely practiced in our laboratories was utilised and the vasoconstriction produced by two corticosteroid formulations of different potency was assessed visually and instrumentally by use of a Minolta chromameter. The instrumental data were corrected for zero-time and unmedicated site readings. In addition, Euclidean distances were calculated using all data generated by the instrument. Results. Individually the a-, b- and L-scale chromameter values are imprecise and there is negligible vasoconstriction response recorded for the moderately potent formulation. Arithmetical manipulation of the data as suggested by the FDA does not appear to improve the quality of the data in any way. Euclidean distance analysis more closely resembles the visual data and appears to have better precision. Conclusions. It is clear that mathematical correction of chromameter data is unnecessary, especially since the instrumental data are extremely imprecise. Furthermore, the assessment of each individual chromameter index does not adequately characterise the blanching response profile. It is therefore suggested that Euclidean distance may be a better measure on which to base an analysis of bioequivalence than the truncated data set methodology currently suggested by the FDA.
- Full Text: false
Evaluation of the proposed FDA pilot-dose response methodology for topical corticosteroid bioeqivalence testing [authors' reply in Letters to the Editor]
- Smith, Eric W, Walker, Roderick B, Haigh, John M, Kanfer, Isadore
- Authors: Smith, Eric W , Walker, Roderick B , Haigh, John M , Kanfer, Isadore
- Date: 1998
- Language: English
- Type: text , Article
- Identifier: vital:6423 , http://hdl.handle.net/10962/d1006558
- Description: Reply to: Letter to the Editor by Singh GJ; Fleischer N; Lesko L; Williams R - relating to original article in Pharmaceutical Research (USA), Mar 1997, vol. 14, pp. 303-308.
- Full Text: false
- Authors: Smith, Eric W , Walker, Roderick B , Haigh, John M , Kanfer, Isadore
- Date: 1998
- Language: English
- Type: text , Article
- Identifier: vital:6423 , http://hdl.handle.net/10962/d1006558
- Description: Reply to: Letter to the Editor by Singh GJ; Fleischer N; Lesko L; Williams R - relating to original article in Pharmaceutical Research (USA), Mar 1997, vol. 14, pp. 303-308.
- Full Text: false
New developments in the methodology available for the assessment of topical corticosteroid-induced skin blanching
- Haigh, John M, Smith, Eric W, Maibach, Howard I
- Authors: Haigh, John M , Smith, Eric W , Maibach, Howard I
- Date: 1998
- Language: English
- Type: text , Article
- Identifier: vital:6384 , http://hdl.handle.net/10962/d1006305
- Description: Since the publication of the previous edition of this book there have been considerable developments and controversy in the field of topical corticosteroid bioequivalence assessment. There has been considerable discussion in the literature concerning the use of the Minolta chromameter for the measurement of corticosteroid-induced skin blanching, as it is believed this instrument would produce more objective results than the visual grading procedure. These efforts culminated in the release of a guidance document from the Food and Drug Administration (FDA) detailing the procedures to be followed for the determination of topical corticosteroid bioequivalence using the chromameter. Since the promulgation of this document there have been challenges on the validity and scientific merit of the documented procedures, and recently the FDA itself conceded that it may be necessary to redefine some of the protocol evaluations. This chapter attempts to redefine the current standing of the two methods of response assessment.
- Full Text:
- Authors: Haigh, John M , Smith, Eric W , Maibach, Howard I
- Date: 1998
- Language: English
- Type: text , Article
- Identifier: vital:6384 , http://hdl.handle.net/10962/d1006305
- Description: Since the publication of the previous edition of this book there have been considerable developments and controversy in the field of topical corticosteroid bioequivalence assessment. There has been considerable discussion in the literature concerning the use of the Minolta chromameter for the measurement of corticosteroid-induced skin blanching, as it is believed this instrument would produce more objective results than the visual grading procedure. These efforts culminated in the release of a guidance document from the Food and Drug Administration (FDA) detailing the procedures to be followed for the determination of topical corticosteroid bioequivalence using the chromameter. Since the promulgation of this document there have been challenges on the validity and scientific merit of the documented procedures, and recently the FDA itself conceded that it may be necessary to redefine some of the protocol evaluations. This chapter attempts to redefine the current standing of the two methods of response assessment.
- Full Text:
The requirements for accurate analysis of pharmaceutical research at South African Universities
- Haigh, John M, Smith, Eric W
- Authors: Haigh, John M , Smith, Eric W
- Date: 1998
- Language: English
- Type: text , Article
- Identifier: vital:6367 , http://hdl.handle.net/10962/d1006067
- Description: International Pharmaceutical Abstracts is a valuable database for pharmaceutical research, although the multisiciplinary nature of this field implies that the database should only be the starting point of a search. This database is totally inappropriate for comparing outputs of individual pharmacy teaching institutions.
- Full Text:
- Authors: Haigh, John M , Smith, Eric W
- Date: 1998
- Language: English
- Type: text , Article
- Identifier: vital:6367 , http://hdl.handle.net/10962/d1006067
- Description: International Pharmaceutical Abstracts is a valuable database for pharmaceutical research, although the multisiciplinary nature of this field implies that the database should only be the starting point of a search. This database is totally inappropriate for comparing outputs of individual pharmacy teaching institutions.
- Full Text:
- «
- ‹
- 1
- ›
- »