Lack of adverse effects on fertility of female cd‐1 mice exposed to repetitive intravaginal gel–microemulsion formulation of a dual‐function anti‐HIV agent: aryl phosphate derivative of bromo‐methoxy‐zidovudine (compound WHI‐07)

Abstract

5-bromo-6-methoxy-5,6-dihydro-3(')-azidothymidine-5(')-(p-bromophenyl) methoxyalaninyl phosphate (WHI-07), a novel bromo-methoxy-substituted aryl phosphate derivative of zidovudine (ZDV), is a potent dual-function contraceptive agent with anti-HIV activity. Its potential for reproductive toxicity was assessed in a series of experiments using CD-1 mice under the conditions of its intended use as an intravaginal microbicide. Female CD-1 mice were exposed intravaginally to a gel-microemulsion formulation containing 0%, 0.5%, 1.0% or 2.0% WHI-07 for up to 13 weeks. On a molar basis, these concentrations represent 1400-5700 times its in vitro spermicidal IC(50) and 1.4-5.7(x10(6)) times its in vitro anti-HIV IC(50). We examined the effects of intravaginally administered WHI-07 on: ovulation efficiency; in vivo fertilization and early embryonic, fetal development; and reproductive outcome, including neonatal survival and pup development. Compound WHI-07 was administered intravaginally during superovulation, organogenesis and prior to mating for 5 and 10 consecutive days and for 13 weeks, respectively. Mice were evaluated for ovulation efficiency and fertilization rate and cleavage 14 and 40 h after human chorionic gonadotropin (hCG) injection, respectively. Pregnant mice were administered 2% WHI-07 intravaginally during gestation days (GD) 6-15 and measures of teratogenicity were evaluated on GD 17. For short-term toxicity study, mice were given intravaginal treatment of gel-microemulsion containing 0%, 0.5%, 1.0% and 2.0% WHI-07 for 13 weeks and then mated with untreated males to evaluate potential reproductive and developmental effects. Repeated intravaginal exposure of mice to 2% WHI-07 had no adverse effects on ovulation response, mean number of eggs recovered or the percentage of eggs fertilized or cleaved. No evidence of reproductive toxicity, fetal toxicity or teratogenicity was found following repetitive intravaginal application of 2% WHI-07 during the period of organogenesis. Furthermore, repeated intravaginal exposure of mice to 0.5-2.0% WHI-07 for 13 weeks had no adverse effect on the subsequent reproductive capability, perinatal outcome or growth and development of the offspring. Compound WHI-07 shows unique clinical potential as a safe, dual-function vaginal contraceptive for curbing mucosal and perinatal HIV transmission.

Developmental Toxicology Studies of WHI-07, a Novel Nucleoside Analogue-Based Dual-Function Microbicide, Administered Intravaginally to Rabbits

“…Repeated intravaginal application of WHI-07 for up to 13 weeks did not cause local, systemic, or reproductive toxicity in mice (8,19). WHI-07 did not exhibit mucosal toxicity, maternal toxicity, fetotoxicity, embryotoxicity, or teratogenicity in mice or rabbits (7,9,18). Histological evaluation of rabbit vaginal tissues immediately after daily intravaginal application of 2% WHI-07 in gel-microemulsion for 10 consecutive days revealed lack of epithelial cell disruption, leukocyte influx, vaginal erythema, or submucosal edema (mean individual scores 0-2 out of 4; total scores 2-5 out of 16) (7).…”

“…Furthermore, repeated intravaginal exposure of CD-1 mice to WHI-07 for up to 13 weeks had no adverse effects on ovulation response, mean number of eggs recovered, the percent of eggs fertilized and cleaved or their subsequent reproductive capability (8,9,19). In molecular genotoxicity studies, WHI-07 did not increase DEL recombination frequency in yeast and did not activate any of the DNA damage-associated promoters in human HepG2 cells using the CAT-Tox(L) assay.…”

“…In previous subchronic and reproductive toxicity studies and a two-year carcinogenicity study, daily intravaginal application of 0.5 to 2.0% WHI-07 via a gel-microemulsion, was shown to cause no local, systemic and reproductive toxicity or increased carcinogenicity in mice. To evaluate the developmental toxicity potential of WHI-07 in a nonrodent model, subgroups of 20 superovulated NZW rabbits were artificially inseminated and exposed intravaginally to a gel-microemulsion containing 0, 0.5, 1.0, or 2.0% WHI-07 during major organogenesis [gestation days [6][7][8][9][10][11][12][13][14][15][16][17][18]. The dose of WHI-07 was equivalent to 1.4 × 10 6 to 5.7 × 10 6 times its anti-HIV IC 50 and 1400 to 5700 times its spermicidal EC 50 .…”

Influence of long-term stability conditions on microbicidal nucleoside prodrug (WHI-07)-loaded gel-microemulsion

“…In animal toxicity studies performed in mice, rabbits, cats, and/or pigs, intravaginal administration of gelmicroemulsion with or without 2.0% WHI-07 was not associated with any mucosal, systemic, developmental, and/ or reproductive toxicity. [22][23][24][25][26][27][28] Consequently, the shelf-life/ stability of WHI-07-loaded gel-microemulsion at 3 controlled temperatures (4ºC, 25ºC, and 40-C) was determined using a validated high-performance liquid chromatography (HPLC) method for up to 24 weeks (6 months). soya lecithin) was from American Lecithin Co (Danbury, CT); and propylene glycol was obtained from Spectrum Quality Products Inc (New Brunswick, NJ).…”

Antiretroviral Spermicide WHI-07 Prevents Vaginal and Rectal Transmission of Feline Immunodeficiency Virus in Domestic Cats

“…WHI-07-containing gel microemulsion is a potent vaginal contraceptive in the rabbit model (12). In preclinical studies, repetitive intravaginal administration of 2% WHI-07 via a gel microemulsion corresponding to 5.7 ϫ 10 6 times its in vitro anti-HIV IC 50 and 5,700 times its spermicidal 50% effective concentration for up to 13 weeks was not associated with mucosal, systemic, or reproductive toxicity in test animal species (13)(14)(15)(16). Repeated intravaginal administration of WHI-07 during the period of major organogenesis at concentrations as high as 2% did not produce teratogenicity or other developmental toxicity in rodent and nonrodent species tested (16).…”