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Journal of Pharmaceutical and... Mar 2006A stability indicating, reversed-phase high performance liquid chromatographic method was developed for the quantification of Apomine, tetraisopropyl...
A stability indicating, reversed-phase high performance liquid chromatographic method was developed for the quantification of Apomine, tetraisopropyl 2-(3,5-di-tert-butyl-4-hydroxyphenyl)-ethyl-1, 1-bisphosphonate, in a topical cream formulation. Analysis of Apomine in the cream formulation was performed through a dilution of the cream base with tetrahydrofuran. This allowed the current method to bypass extraction and/or centrifugation for direct injection and analysis. Separation was achieved using an Alltima C18 5 microm, 150 mm x 2.1 mm column and employed a gradient procedure, beginning with acetonitrile-water (65:35, v/v), at 0.6 mL/min for 9 min, followed by a rinse with isopropyl alcohol for 9 min. The complete gradient method has been optimized to separate Apomine from the nonpolar cream components, wash and equilibrate the column in a 30-min assay. This report demonstrates that this method is effective for quantification of Apomine in a cream formulation.
Topics: Administration, Topical; Antineoplastic Agents; Chemistry, Pharmaceutical; Chromatography, High Pressure Liquid; Diphosphonates; Ointments; Reproducibility of Results; Spectrophotometry, Ultraviolet
PubMed: 16181759
DOI: 10.1016/j.jpba.2005.07.046 -
Journal of Cellular Biochemistry Jun 2005The human epidermal cell (HEC) assay, which uses carcinogen exposed normal skin keratinocytes to screen for cancer prevention efficacy, was used to screen possible... (Comparative Study)
Comparative Study
The human epidermal cell (HEC) assay, which uses carcinogen exposed normal skin keratinocytes to screen for cancer prevention efficacy, was used to screen possible preventive agents. The endpoints measured were inhibition of carcinogen-induced growth and induction of involucrin, an early marker of differentiation. Sixteen of twenty agents (apigenin, apomine, budesonide, N-(2-carboxyphenyl)retinamide, ellagic acid, ibuprofen, indomethacin, melatonin, (-)-2-oxo-4-thiazolidine carboxylic acid, polyphenon E, resveratrol, beta-sitosterol, sulfasalazine, vitamin E acetate, and zileuton) were positive in at least one of the two assay endpoints. Four agents (4-methoxyphenol, naringenin, palmitoylcarnitine chloride, and silymarin) were negative in the assay. Nine of the sixteen agents were positive for both endpoints. Agents that showed the greatest response included: ellagic acid > budesonide, ibuprofen > apigenin, and quinicrine dihydrochloride. Fifty-eight of sixty-five agents that have been evaluated in the HEC assay have also been evaluated in one or more rodent bioassays for cancer prevention and several are in clinical trials for cancer prevention. The assay has an overall predictive accuracy of approximately 91.4% for efficacy in rodent cancer prevention irrespective of the species used, the tissue model, or the carcinogen used. Comparison of the efficacious concentrations in vitro to plasma levels in clinical trials show that concentrations that produced efficacy in the HEC assay were achieved in clinical studies for 31 of 33 agents for which plasma levels and/or C(max) levels were available. For two agents, 9-cis-retinoic acid (RA) and dehydroepiandrosterone (DHEA), the plasma levels greatly exceeded the highest concentration (HC) found to have efficacy in vitro. Thus, the HEC assay has an excellent predictive potential for animal efficacy and is responsive at clinically achievable concentrations.
Topics: Animals; Anticarcinogenic Agents; Cells, Cultured; Clinical Trials as Topic; Drug Evaluation; Humans; Keratinocytes; Neoplasms
PubMed: 15786488
DOI: 10.1002/jcb.20426 -
Biochemical and Biophysical Research... Apr 2005The 1,1-bisphosphonate ester family member apomine (SR-45023A) is known to have anti-tumour activity in various cancer cell types. The aims of this study were to...
The 1,1-bisphosphonate ester family member apomine (SR-45023A) is known to have anti-tumour activity in various cancer cell types. The aims of this study were to determine the effect of apomine on the growth of two breast cancer cell lines, MCF-7 and MDA-MB-231, to ascertain whether any growth inhibitory effects found were due to induction of apoptosis, and to investigate the mechanism of action of apomine. Apomine caused significant growth inhibition of both cell lines after 72h of treatment. Apomine-induced growth inhibition was associated with caspase and p38 MAPK activation and DNA fragmentation. Apomine had no effect on Ras localisation, nor did addition of mevalonate to treatment media prevent apomine-induced apoptosis. We conclude that apomine induces apoptosis in breast cancer cells, an effect that is independent of oestrogen receptor status and is not via inhibition of the mevalonate pathway. Our study suggests apomine is a potential anti-neoplastic drug in breast cancer treatment.
Topics: Antineoplastic Agents; Apoptosis; Breast Neoplasms; Caspases; Cell Line, Tumor; Cell Proliferation; DNA Damage; Diphosphonates; Dose-Response Relationship, Drug; Enzyme Activation; Humans; p38 Mitogen-Activated Protein Kinases
PubMed: 15737653
DOI: 10.1016/j.bbrc.2005.02.032 -
British Journal of Clinical Pharmacology Aug 20041) To characterize the population pharmacokinetics of apomine in healthy males and in male and female patients with solid tumours and 2) to understand more fully the... (Meta-Analysis)
Meta-Analysis
AIMS
1) To characterize the population pharmacokinetics of apomine in healthy males and in male and female patients with solid tumours and 2) to understand more fully the influence of induction and between- and within-subject variability on exposure to drug using Monte Carlo simulation.
METHODS
Apomine was administered once- or twice-daily with or without food in single and multiple oral doses of 30-2100 mg to healthy males (n = 19) and patients with solid tumours (n = 19). The data were divided into model development and validation sets. Models were developed using standard population methods. These were the identification of an appropriate base model, calculation of the empirical Bayes estimates of the primary pharmacokinetic parameters, covariate screening, forward stepwise addition of covariates using the likelihood ratio test as a model selection criteria, and backwards elimination to obtain the final model. To study the influence of data from individual subjects, the model development dataset was subjected to the delete-1 jack-knife and the final model was fitted to each jack-knifed dataset. Principal components analysis of the jack-knifed matrix of model parameters identified two influential subjects who were removed from the dataset, and the final model contained data from the remaining subjects. Model validation was examined using goodness of fit statistics and relative error measures using independent datasets from cancer patients. The model provided a reasonable approximation to the pharmacokinetic measurements in the validation datasets. Computer simulations were undertaken to understand further the pharmacokinetics of apomine in otherwise healthy females, a population not yet studied.
RESULTS
Apomine pharmacokinetics were complex and consistent with a two-compartment model with a lag-time. Apparent oral clearance at baseline and apparent volume of distribution at steady-state were larger in healthy males than in cancer patients (41 ml h(-1) and 14.1 l vs 10 ml h(-1) and 8.9 l, respectively, for a 75 kg person). Clearance was time-variant showing a maximal increase with full induction of 320 ml h(-1), independent of patient type. The time to reach 50% maximal induction was about 2 days. The fraction of drug absorbed was relatively constant at doses less than 100-200 mg once daily but decreased at higher doses. Food also decreased relative bioavailability by 36%. Patient characteristics had no effect on apomine pharmacokinetics except for weight, which was proportional to the volume of the central compartment. Between-subject variability (68% for clearance, 30% for central volume, and 141% for peripheral volume) was moderate to large and independent of patient type. Inter-occasion variability was small (18% for both clearance and central volume). Residual variability was modelled with an additive and proportional error model. Cancer patients had slightly higher plasma concentrations than healthy males but this difference was probably not clinically significant. Steady-state was reached in about 3-4 days after once-daily drug administration. The half-life of apomine after three weeks of once-daily dosing was 41 h in cancer patients and 32 h in healthy males.
CONCLUSIONS
A population model for apomine has been developed has been developed that characterizes its pharmacokinetics in cancer patients and healthy subjects under a variety of conditions.
Topics: Adolescent; Adult; Aged; Antineoplastic Agents; Area Under Curve; Clinical Trials, Phase I as Topic; Clinical Trials, Phase II as Topic; Diphosphonates; Female; Humans; Male; Middle Aged; Models, Chemical; Monte Carlo Method; Neoplasms
PubMed: 15255796
DOI: 10.1111/j.1365-2125.2004.02111.x -
The Journal of Biological Chemistry Feb 2004Apomine, a novel 1,1-bisphosphonate ester, has been shown to lower plasma cholesterol concentration in several species. Here we show that Apomine reduced the levels of...
Apomine, a novel hypocholesterolemic agent, accelerates degradation of 3-hydroxy-3-methylglutaryl-coenzyme A reductase and stimulates low density lipoprotein receptor activity.
Apomine, a novel 1,1-bisphosphonate ester, has been shown to lower plasma cholesterol concentration in several species. Here we show that Apomine reduced the levels of 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGR), the rate-limiting enzyme in the mevalonate pathway, both in rat liver and in cultured cells. Apomine resembles sterols such as 25-hydroxycholesterol in its ability to potently accelerate the rate of HMGR degradation by the ubiquitin-proteasome pathway, a process that depends on the transmembrane domain of the enzyme. The similarity between Apomine and sterols in promoting rapid HMGR degradation extends to its acute requirements for ongoing protein synthesis and mevalonate-derived non-sterol product(s) as a co-regulator. Yet, at suboptimal concentrations, sterols potentiated the effect of Apomine in stimulating HMGR degradation, indicating that these agents act via distinct modes. Furthermore, unlike sterols, Apomine inhibited the activity of acyl-CoA:cholesterol acyltransferase in intact cells but not in cell-free extracts. Apomine stimulated the cleavage of the precursor of sterol-regulatory element-binding protein-2 and increased the activity of low density lipoprotein receptor pathway. This Apomine-enhanced activation of sterol-regulatory element-binding protein-2 was prevented by sterols or mevalonate. Taken together, our results provide a molecular mechanism for the hypocholesterolemic activity of Apomine.
Topics: Animals; Anticholesteremic Agents; CHO Cells; Cell-Free System; Cells, Cultured; Cholesterol; Cricetinae; DNA-Binding Proteins; Diphosphonates; Dose-Response Relationship, Drug; HeLa Cells; Humans; Hydroxycholesterols; Hydroxymethylglutaryl CoA Reductases; Immunoblotting; Liver; Male; Models, Chemical; Precipitin Tests; Rats; Rats, Wistar; Receptors, LDL; Sterol Regulatory Element Binding Protein 2; Time Factors; Transcription Factors
PubMed: 14627708
DOI: 10.1074/jbc.M308094200 -
Clinical Cancer Research : An Official... May 2001To study the human pharmacokinetics and in vitro cytotoxicity of Apomine, an p.o. administered, nonmyelosuppressive agent that selectively inhibits cell proliferation... (Clinical Trial)
Clinical Trial
PURPOSE
To study the human pharmacokinetics and in vitro cytotoxicity of Apomine, an p.o. administered, nonmyelosuppressive agent that selectively inhibits cell proliferation and induces tumor cell apoptosis through the farnesoid X receptor.
EXPERIMENTAL DESIGN
Seven solid cancer patients who participated in an ongoing Phase I study of Apomine and received the starting dose level of 125 mg/m(2)/day x 14 days every 3 weeks underwent a pharmacokinetic study on day 14 of the first course. Plasma concentrations of Apomine were assayed with a Hewlett Packard gas chromatograph using a nitrogen phosphorus detector and HP-5 15m x 0.32-mm column. Fresh human ovarian cancer tumor samples were obtained during initial exploratory laparotomy from 35 chemotherapy-naive, advanced stage epithelial ovarian cancer patients. Tumor samples were tested for sensitivity to Apomine, carboplatin, cisplatin, paclitaxel, and topotecan using an in vitro clonogenic [(3)H]thymidine end point assay.
RESULTS
Pharmacokinetic analysis revealed a mean Apomine plasma C(max) of 16.4 +/- 9.1 microg/ml (29.1 microM), a mean plasma AUC(0--12 h) of 173.4 +/- 105 microg. h/ml (308 microM. h), and a mean t(1/2 (24--192 h)) of 156.2 +/- 42.9 h. In vitro assay results showed that 63 and 91% of the ovarian cancers were sensitive (i.e., >70% inhibition of tumor cell growth) to Apomine at concentrations of 10 and 20 microM. The sensitivity rates were 91% for carboplatin (270 microM), 88% for cisplatin (33 microM), 41% for paclitaxel (5.9 microM), and 85% for topotecan (2.2 microM).
CONCLUSIONS
These in vitro assay results, taken together with our preliminary plasma pharmacokinetic data, suggest that Apomine should be clinically active at the 125 mg/m(2) dose level.
Topics: Administration, Oral; Antineoplastic Agents; Cell Division; Diphosphonates; Drug Screening Assays, Antitumor; Female; Humans; Male; Neoplasms; Tumor Cells, Cultured
PubMed: 11350890
DOI: No ID Found -
Current Pharmaceutical Design Mar 2001The orphan nuclear receptors FXR and LXRalpha have become challenging targets for the discovery of new therapeutic agents. Bile acids and hydroxysterol intermediates are... (Review)
Review
The orphan nuclear receptors FXR and LXRalpha have become challenging targets for the discovery of new therapeutic agents. Bile acids and hydroxysterol intermediates are the respective natural ligands of these two structurally and functionally closely related receptors. Both FXR and LXRalpha; are thought to play a major role in the control of cholesterol catabolism by regulating the expression of cholesterol 7alpha-hydroxylase, the rate limiting enzyme of bile acid synthesis. Reverse cholesterol transport might also be affected by FXR and LXR since they control the expression of PLTP and CETP, two proteins involved in the transfer of phospholipid, cholesterol and cholesteryl esters among plasma lipoproteins. A new class of potent synthetic activators of FXR, the 1,1-bisphosphonate esters, has been discovered which up regulate the Intestinal Bile Acid Binding Protein gene (I-BABP) as demonstrated for chenodeoxycholic acid, however there are no known synthetic activators yet identified for LXRalpha. The evaluation of FXR as a potential target for the development of drugs affecting plasma cholesterol can take advantage of the fact that the activators of FXR (farnesol, bile acids and the 1,1-bisphosphonate esters) have been studied in various in vitro and in vivo models. Administration of chenodeoxycholic acid to animals and man did not result in the increase in plasma cholesterol expected from a decrease in cholesterol 7alpha-hydroxylase expression. Like farnesol, the 1,1-bisphosphonate esters increase the rate of degradation of HMGCoA reductase and have the unexpected property of inducing hypocholesterolemia in normal animals. The natural and synthetic FXR agonists trigger differentiation, inhibit cell proliferation and are potent inducers of apoptosis. The 1,1-bisphosphonate ester SR-45023A (Apomine) is presently being developed as an antineoplastic drug.
Topics: Amino Acid Sequence; Animals; Anticholesteremic Agents; Antineoplastic Agents; Bile Acids and Salts; Cholesterol; Cholesterol 7-alpha-Hydroxylase; DNA-Binding Proteins; Drug Design; Humans; Lipid Metabolism; Liver X Receptors; Molecular Sequence Data; Orphan Nuclear Receptors; Receptors, Cytoplasmic and Nuclear; Receptors, Steroid; Transcription Factors
PubMed: 11254888
DOI: 10.2174/1381612013398185 -
Arzneimittel-Forschung Apr 2000Tetra-iso-propyl 2-(3,5-di-tert-butyl-4-hydroxyphenyl)ethyl-1,1-diphosphonate (CAS 126411-13-0, SR-9223i) is a member of a new class of compounds with multiple... (Comparative Study)
Comparative Study
Tetra-iso-propyl 2-(3,5-di-tert-butyl-4-hydroxyphenyl)ethyl-1,1-diphosphonate (CAS 126411-13-0, SR-9223i) is a member of a new class of compounds with multiple antiatherosclerotic activities. This report not only describes the cholesterol-lowering properties in four species of animals fed normocholesterolaemic diets but also reductions in lipid deposition in the arteries of cholesterol-fed New Zealand white rabbits following the administration of SR-9223i. Plasma cholesterol concentrations were reduced in mice by 27% (200 mg/kg/day administered in the diet for 10 days), in hamsters by 33% (200 mg/kg/day administered in the diet for 8 days), in dogs by 16% (25 mg/kg/day p.o. for 28 days) and 23% (75 mg/kg/day p.o. for 28 days) and in monkeys by 22% (25 mg/kg/day p.o. for 28 days). Further, the deposition of cholesterol, especially in the esterified form, in the aortae of cholesterol-fed New Zealand white rabbits was inhibited by SR-9223i (50 and 100 mg/kg/day p.o.). At the higher dose, the cholesteryl ester content of the aorta was half that of control animals. SR-9223i, at both doses, also inhibited the accumulation of cholesterol in the liver. SR-9223i has been shown to suppress HMG CoA reductase activity, inhibit ACAT activity and prevent lipid oxidation. These activities, demonstrated in vitro, have now been shown to translate into lipid lowering and antiatherosclerotic activities in vivo.
Topics: Animals; Anticholesteremic Agents; Aorta; Arteriosclerosis; Body Weight; Cholesterol; Cholesterol Esters; Cholesterol, Dietary; Cricetinae; Diphosphonates; Dogs; Lipoproteins; Liver; Macaca fascicularis; Male; Mice; Rabbits; Species Specificity
PubMed: 10800637
DOI: 10.1055/s-0031-1300217 -
Biochemical and Biophysical Research... Apr 2000Apomine (SR-45023A) is a new antineoplastic compound which is currently in clinical trials and representative of the family of cholesterol synthesis inhibitors... (Comparative Study)
Comparative Study
Apomine (SR-45023A) is a new antineoplastic compound which is currently in clinical trials and representative of the family of cholesterol synthesis inhibitors 1,1-bisphosphonate esters. Apomine inhibits growth of a wide variety of tumor cell lines with IC(50) values ranging from 5 to 14 microM. The antiproliferative activity of apomine was studied in comparison with that of other inhibitors of the mevalonate/isoprenoid pathway of cholesterol synthesis, simvastatin, farnesol, and 25-hydroxycholesterol. All these compounds inhibit 3-hydroxy-3-methylglutaryl-coenzyme A reductase activity. Apomine (IC(50) = 14 microM), simvastatin (IC(50) = 3 microM), farnesol (IC(50) = 60 microM), and 25-hydroxycholesterol (IC(50) = 2 microM) inhibited HL60 cell growth. Growth inhibition due to simvastatin was reverted by mevalonate, whereas the antiproliferative activity of apomine, farnesol, and 25-hydroxycholesterol was not. Apomine triggered apoptosis in HL60 cells in less than 2 h. Apomine and farnesol induced caspase-3 activity at concentrations similar to their IC(50) values for cell proliferation, whereas a 10-fold excess of simvastatin was necessary to trigger apoptosis compared to its potency on proliferation. Caspase-3 activity was not induced by 25-hydroxycholesterol. The overall similar profile on mevalonate synthesis inhibition, cell growth inhibition, and apoptosis suggests that apomine acts as a synthetic mimetic of farnesol.
Topics: Anticholesteremic Agents; Antineoplastic Agents; Apoptosis; Cell Division; Diphosphonates; Dose-Response Relationship, Drug; Farnesol; Humans; Hydroxycholesterols; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Mevalonic Acid; Molecular Mimicry; Simvastatin; Terpenes; Tumor Cells, Cultured
PubMed: 10733934
DOI: 10.1006/bbrc.2000.2421