Pharmacokinetics, safety and preliminary pharmacodynamic evaluation of DARE-VVA1: a soft gelatin capsule containing tamoxifen for the treatment of vulvovaginal atrophy.

OBJECTIVE: This study aimed to measure safety, systemic pharmacokinetics and preliminary efficacy of a vaginal tamoxifen capsule (DARE-VVA1) among postmenopausal women with moderate-to-severe vulvovaginal atrophy. METHODS: This was a randomized, placebo-controlled, double-blind, phase 1/2 study of DARE-VVA1, in four doses (1, 5, 10 and 20 mg). RESULTS: Seventeen women were enrolled and 14 completed the 8-week treatment. DARE-VVA1 was safe. All adverse events were of mild or moderate severity and distributed similarly among active and placebo groups. Plasma tamoxifen concentrations were highest among women using DARE-VVA1 20 mg, but the maximum mean (standard deviation) plasma tamoxifen concentrations on day 1 (2.66 ± 0.85 ng/ml) and day 56 (5.69 ± 1.87 ng/ml) were <14% of those measured after one oral tamoxifen dose. Active study product users had significant decreases from pre-treatment baseline in vaginal pH and proportion of vaginal parabasal cells (p = 0.04 for both endpoints), with women randomized to the 10 mg or 20 mg dose experiencing the largest treatment impact. The severity of vaginal dryness and dyspareunia decreased significantly from baseline with active study product use (p = 0.02 for both endpoints). CONCLUSIONS: DARE-VVA1 is safe and results in minimal systemic exposure to tamoxifen. Preliminary efficacy data support further development of this product.

Changes in membrane lipid composition during saline growth of the fresh water cyanobacterium Synechococcus 6311.

Growth of Synechococcus 6311 in the presence of 0.5 molar NaCl is accompanied by significant changes in membrane lipid composition. Upon transfer of the cells from a low salt' (0.015 molar NaCl) to high salt' (0.5 molar NaCl) growth medium at different stages of growth, a rapid decrease in palmitoleic acid (C16:1 delta 9) content was accompanied by a concomitant increase in the amount of the two C18:1 acids (C18:1 delta 9, C18:1 delta 11), with the higher increase in oleic acid C18:1 delta 9 content. These changes began to occur within the first hour after the sudden elevation of NaCl and progressed for about 72 hours. The percentage of palmitic acid (C16:0) and stearic acid (C18:0) remained almost unchanged in the same conditions. High salt-dependent changes within ratios of polar lipid classes also occurred within the first 72 hours of growth. The amount of monogalactosyl diacylglycerol (bilayer-destabilizing lipid) decreased and that of the digalactosyl diacylglycerol (bilayer-stabilizing lipid) increased. Consequently, in the three day old cells, the ratio of monogalactosyl diacylglycerol to digalactosyl diacylglycerol in the membranes of high salt-grown cells was about half of that in the membranes of low salt-grown cells. The total content of anionic lipids (phosphatidylglycerol and sulfoquinovosyl diacylglycerol) was always higher in the isolated membranes and the whole cells from high salt-grown cultures compared to that in the cells and membranes from low salt-grown cultures. All the observed rearrangements in the lipid environment occurred in both thylakoid and cytoplasmic membranes. Similar lipid composition changes, however, to a much lesser extent, were also observed in the aging, low salt-grown cultures. The observed changes in membrane fatty acids and lipids composition correlate with the alterations in electron and ion transport activities, and it is concluded that the rearrangement of the membrane lipid environment is an essential part of the process by which cells control membrane function and stability.

An animal model for human osteosarcoma.

Osteosarcomas formed in antilymphocyte serum (ALS)-treated hamsters when 2x10(6) TE-85 human osteosarcoma cells (maintained in tissue culture) infected with M-MSV (RD-114) virus were injected adjacent to the femur or the scapula; undifferentiated sarcomas formed when 1 x 10(6) cells were injected subcutaneously. Tumors were palpable 10 to 14 days after the cells were injected and grew progressively until the animals died (mean survival time was 30 days). All animals had pulmonary metastases. Neither the subcutaneous sarcomas nor the metastases contained bone or osteoid; however, the osteosarcomas adjacent ot the femur and scapula contained collagen, osteoid and calcified bone when observed by light and electron microscopy. These results indicate that the TE-85-M-MSV cell-ALS hamster system is an animal model for the study of osteosarcomas of human cell origin.