In vitro preclinical testing of nonoxynol-9 as potential anti-human immunodeficiency virus microbicide: a retrospective analysis of results from five laboratories.
The first product to be clinically evaluated as a microbicide contained the nonionic surfactant nonoxynol-9 (nonylphenoxypolyethoxyethanol; N-9). Many laboratories have used N-9 as a control compound for microbicide assays. However, no published comparisons of the results among laboratories or attempts to establish standardized protocols for preclinical testing of microbicides have been performed. In this study, we compared results from 127 N-9 toxicity and 72 efficacy assays that were generated in five different laboratories over the last six years and were performed with 14 different cell lines or tissues. Intra-assay reproducibility was measured at two-, three-, and fivefold differences using standard deviations. Interassay reproducibility was assessed using general linear models, and interaction between variables was studied using step-wise regression. The intra-assay reproducibility within the same N-9 concentration, cell type, assay duration, and laboratory was consistent at the twofold level of standard deviations. For interassay reproducibility, cell line, duration of assay, and N-9 concentration were all significant sources of variability (P < 0.01). Half-maximal toxicity concentrations for N-9 were similar between laboratories for assays of similar exposure durations, but these similarities decreased with lower test concentrations of N-9. Results for both long (>24 h) and short (<2 h) exposures of cells to N-9 showed variability, while assays with 4 to 8 h of N-9 exposure gave results that were not significantly different. This is the first analysis to compare preclinical N-9 toxicity levels that were obtained by different laboratories using various protocols. This comparative work can be used to develop standardized microbicide testing protocols that will help advance potential microbicides to clinical trials.
Beer
Brigitte E
BE
Southern Research Institute, 431 Aviation Way, Frederick, MD 21701, USA. beer@sri.org
Doncel
Gustavo F
GF
Krebs
Fred C
FC
Shattock
Robin J
RJ
Fletcher
Patricia S
PS
Buckheit
Robert W
RW
Watson
Karen
K
Dezzutti
Charlene S
CS
Cummins
James E
JE
Bromley
Ena
E
Richardson-Harman
Nicola
N
Pallansch
Luke A
LA
Lackman-Smith
Carol
C
Osterling
Clay
C
Mankowski
Marie
M
Miller
Shendra R
SR
Catalone
Bradley J
BJ
Welsh
Patricia A
PA
Howett
Mary K
MK
Wigdahl
Brian
B
Turpin
Jim A
JA
Reichelderfer
Patricia
P
D019380:Anti-HIV Agents / Q000494:pharmacology*; D000890:Anti-Infective Agents / Q000494:pharmacology*; D002460:Cell Line; D015497:HIV-1 / Q000187:drug effects / Q000502:physiology; D017137:Nonoxynol / Q000494:pharmacology*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014779:Virus Replication / Q000187:drug effects
D019380:Anti-HIV Agents; D000890:Anti-Infective Agents; D017137:Nonoxynol