Comparison of pharmacokinetics and bioavailability of bedaquiline fumarate, benzoate and maleate in dogs.

BACKGROUND: Bedaquiline (BDQ) as a fumarate salt is indicated as part of a regimen to treat multidrug-resistant TB (MDR-TB). BDQ benzoate and maleate have been identified as promising alternatives that will encourage generic pharmaceutical houses to manufacture this drug. Our study compared the pharmacokinetics (PK) of BDQ fumarate vs. the maleate and benzoate salts in dogs.METHODS: The PK of BDQ and its active N-desmethyl metabolite M2 following intravenous administration of 1 mg/kg BDQ (as fumarate) and oral administration of 10 mg/kg BDQ as fumarate, benzoate, or maleate salts in suspension to fasted male beagle dogs was evaluated in a parallel-group and crossover study with N = 4 per group. BDQ and M2 plasma concentrations were determined up to 168 h post-dose. T-tests were conducted to compare the area under the curve, AUC0-t among groups.RESULTS: Orally administered fumarate, benzoate, and maleate salts, in parallel-group design, resulted in mean BDQ AUC0-t of 9,267 ± SD 10,182, 19,258 ± SD 11,803, and 15,396 ± SD 9,170 ng.h/ml, respectively; and in a crossover design of 9,267 ± SD 10,182, 17,441 ± SD 24,049, and 18,087 ± SD 19,758 ng.h/ml, respectively. P values were >0.05.CONCLUSION: There was no statistically significant difference in BDQ and M2 AUC0-t following oral administration of fumarate, benzoate and maleate salts in dogs.

Synthesis and evaluation of styrene-maleic acid copolymer conjugated amphotericin B.

Amphotericin B (AmB), which plays a central role in the treatment of systemic fungal infections, is difficult to formulate because it's sparingly soluble in water and organic solvents. We previously prepared AmB-loaded micelles using styrene-maleic acid copolymer (SMA). Although solubilization was achieved by this formulation, stability in the blood circulation was as insufficient as that of Fungizone®, which is a conventional formulation of AmB. Meanwhile, it is well known that polymer-drug conjugates are more stable in circulation than drug-loaded micelles. Therefore, in this study, we developed covalently conjugated SMA-AmB (SMA-AmB conjugate). The SMA-AmB conjugate was found to be soluble and present as micelles in aqueous solution. Furthermore, it was revealed that this micelle behaves as a larger molecule by forming a complex with albumin. The circulation in the blood increased significantly compared to that of Fungizone®, which was suggested to be due to this complex-forming ability. Although in vitro and in vivo antifungal activity of the SMA-AmB conjugate against Saccharomyces cerevisiae was reduced by 1/3 compared to that of Fungizone®, hemolysis decreased to 1/40 or less, and the LD50 decreased to 1/10. In conclusion, it is expected that the SMA-AmB conjugate can be a polymer-therapeutic agent with high antifungal selectivity.

Indium-111 labeling of high-density lipoprotein-mimicking phospholipid-styrene maleic acid copolymer complexes and its biodistribution in mice.

Discoidal lipid nanoparticles mimicking native high-density lipoproteins (HDL) are promising delivery vehicles of drugs and/or imaging agents. However, little is known about the in vivo biodistribution of such discoidal lipid nanoparticles compared to liposomes, clinically available spherical lipid nanoparticles. Recently, it has been reported that synthetic polymers instead of apolipoproteins can be complexed with phospholipid to form discoidal nanoparticles. In the present study, with the aim of developing phospholipid-synthetic polymer complexes for future clinical applications, the biodistribution of such particles in normal mice was investigated. Lipid nanoparticles comprising 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine (POPC) and styrene maleic acid copolymer (SMA), having sizes similar to native HDL, were prepared using the freeze-sonication method. POPC-SMA complexes remained stable at 37°C for at least 3 days in buffer. By devising ways to avoid detrimental effects accompanied by pH reduction and nonspecific binding of 111 In to SMA, POPC-SMA complexes were successfully labeled with 111 In without affecting particle integrity. The biodistribution of POPC-SMA complexes in normal mice was similar to that of discoidal lipid nanoparticles composed of POPC and apolipoprotein A-I, the major protein constituent of native HDL. Unlike liposomes, the accumulation of POPC-SMA complexes in the spleen was low, suggesting that these complexes are not recognized as foreign substances. To the best of our knowledge, this is the first in vivo study of HDL-mimicking phospholipid-synthetic polymer complexes.

Poly(methyl vinyl ether-co-maleic acid) for enhancement of solubility, oral bioavailability and anti-osteoporotic effects of raloxifene hydrochloride.

Raloxifene HCl (RH) has poor water solubility and due to its extensive first pass metabolism; its bioavailability is only 2%. The purpose of the present study was to enhance the aqueous solubility, oral bioavailability and anti-osteoporotic effects of RH by electro-sprayed nanoparticles (NPs) in ovariectomized rats. NPs containing RH and different ratio of poly(methyl vinyl ether-co-maleic acid) (PMVEMA) were electrosprayed. The voltage, distance of needle to the collector, flow rate of the solution and polymeric percentage were optimized according to the size of NPs and drug solubility. The optimized formulation was characterized by SEM, XRD, DSC, and FTIR. The pharmacokinetic parameters were studies by oral administration of a single dose of 15mg/kg in Wistar rats. The anti-osteoporotic effects were studied in female ovariectomized rats. Animals were treated with 6mg/kg/day for 2months then serum calcium, phosphorous and alkaline phosphatase levels were measured. RH loaded electrosprayed NPs showed 10-fold enhanced solubility compared to the free drug. Moreover, the XRD and SEM tests displayed an amorphous state of drug in the NPs. FTIR and DSC tests revealed no interaction between the polymer and the drug. Serum calcium, phosphorous and alkaline phosphatase levels were significantly decreased in ovariectomized rats receiving oral RH NPs (P<0.05). No significant difference was detected between RH NPs and estradiol groups (P>0.05). Oral bioavailability of NPs showed 7.5-fold increase compared to the pure drug. The electrosprayed PMVEMA nanoparticles can enhance solubility, bioavailability and antiosteoporotic effects of RH.

The Pharmacokinetics of Fumaric Acid Esters Reveal Their In Vivo Effects.

Fumaric acid ester-based drugs are used for the treatment of psoriasis and multiple sclerosis. All licensed fumaric acid ester drugs contain dimethylfumarate (DMF) as the main active component. Due to the expanding use of oral DMF there is growing scientific interest in determining its as-yet-unknown mechanism of action. However, the pharmacology and chemistry of DMF are often not fully considered in the design and interpretation of experiments; namely, that while DMF is plasma-membrane permeable and has strong effects on many cell types in vitro, it is rapidly metabolized into membrane-impermeable monomethylfumarate (MMF) in vivo. This can lead to significant biological effects being erroneously assigned to DMF. Understanding the pharmacology of DMF means that future work can more closely reflect the state in vivo.

Bioequivalence study of two formulations of flupirtine maleate capsules in healthy male Chinese volunteers under fasting and fed conditions.

AIM: This study developed a high-performance liquid chromatography-tandem mass spectrometry method to simultaneously determine the concentrations of flupirtine and its major active metabolite D-13223 in human plasma in order to assess the bioequivalence (BE) of two flupirtine maleate capsules among healthy male Chinese volunteers under fasting and fed conditions. MATERIALS AND METHODS: There were two single-center, randomized, single-dose, open-label, laboratory-blinded, two-period, cross-over studies which included 24 healthy male Chinese volunteers under fasting and fed conditions, respectively. Plasma samples were collected prior to and up to 48 h after dosing. The concentrations of flupirtine and its major active metabolite D-13223 in plasma samples were determined by a validated method, that is, high-performance liquid chromatography coupled with a tandem mass spectrometry detector. Pharmacokinetic metrics of area from time zero to the last measurable concentration (AUC0-t), area under the plasma concentration-time curve from administration to infinite time (AUC0-∞), and Cmax were used for BE assessment. RESULTS: Forty-eight healthy volunteers who met the criteria were enrolled and completed the study. According to the observation of vital signs and laboratory measurement, no volunteers had any adverse reactions. Under fasting condition, the geometric mean ratios (90% CI) of the test/reference drug for flupirtine were 103.0% (98.1%-108.2%) for AUC0-t, 102.9% (98.2%-107.9%) for AUC0-∞, and 97.0% (85.9%-109.5%) for Cmax. Under fed condition, the geometric mean ratios (90% CI) of the test/reference drug for flupirtine were 101.7% (98.4%-105.1%) for AUC0-t, 101.6% (98.5%-104.8%) for AUC0-∞, and 103.5% (94.7%-113.0%) for Cmax. The difference between test and reference formulations, Tmax, was not statistically significant. The 90% CIs of the test/reference AUC ratio and Cmax ratio of D-13223 were also within the acceptance range for BE both under fasting and fed conditions. CONCLUSION: The two formulations of flupirtine maleate capsule were bioequivalent (the test and the reference products) under fasting and fed conditions, and thus both can be used interchangeably in the clinical setting.

Evaluation of Potential Drug-Drug Interaction Between Delayed-Release Dimethyl Fumarate and a Commonly Used Oral Contraceptive (Norgestimate/Ethinyl Estradiol) in Healthy Women.

Delayed-release dimethyl fumarate (DMF) is an oral therapy for relapsing multiple sclerosis with anti-inflammatory and neuroprotective properties. This 2-period crossover study was conducted to evaluate the potential for drug-drug interaction between DMF (240 mg twice daily) and a combined oral contraceptive (OC; norgestimate 250 µg, ethinyl estradiol 35 µg). Forty-six healthy women were enrolled; 32 completed the study. After the lead-in period (OC alone), 41 eligible participants were randomized 1:1 to sequence 1 (OC and DMF coadministration in period 1; OC alone in period 2) or sequence 2 (regimens reversed). Mean concentration profiles of plasma norelgestromin (primary metabolite of norgestimate) and ethinyl estradiol were superimposable following OC alone and OC coadministered with DMF, with 90% confidence intervals of geometric mean ratios for area under the plasma concentration-time curve over the dosing interval and peak plasma concentration contained within the 0.8-1.25 range. Low serum progesterone levels during combined treatment confirmed suppression of ovulation. The pharmacokinetics of DMF (measured via its primary active metabolite, monomethyl fumarate) were consistent with historical data when DMF was administered alone. No new safety concerns were identified. These results suggest that norgestimate/ethinyl estradiol-based OCs may be used with DMF without dose modification.

Discovery of DS79182026: A potent orally active hepcidin production inhibitor.

Hepcidin has emerged as the central regulatory molecule of systemic iron homeostasis. Inhibition of hepcidin could be a strategy favorable to treating anemia of chronic disease (ACD). We report herein the synthesis and structure-activity relationships (SARs) of a series of benzisoxazole compounds as orally active hepcidin production inhibitors. The optimization study of multi kinase inhibitor 1 led to a potent and bioavailable hepcidin production inhibitor 38 (DS79182026), which showed serum hepcidin lowering effects in a mouse IL-6 induced acute inflammatory model.

Salt Selection Matters: Differential Renal Toxicity With MDV1634.Maleate Versus MDV1634.2HCl.

Salt forms of pharmaceutical compounds can have unique pharmacokinetic and toxicity properties. MDV1634 was evaluated for neurology indication and also demonstrated blood pressure (BP)-lowering effects in nonclinical studies. During the chemistry manufacturing campaign, 2 salt forms, dihydrochloride (2HCl) and maleate (MAL), which improved chemical stability and water solubility of the free base were identified. MDV1634.MAL showed better chemical attributes and was evaluated in toxicology studies for further development. A 28-day oral toxicity study in dogs with MDV1634.MAL demonstrated partially reversible renal toxicity. Although MAL salt is generally regarded as safe, renal toxicity is sometimes observed in rats and dogs. To evaluate contribution of each salt form to renal toxicity and BP lowering, an additional 28-day study was conducted with MDV1634.2HCL and MDV1634.MAL, which included toxicokinetics, continuous BP measurement in a subset of dogs, and sensitive urinary biomarker evaluation for temporal monitorability and reversibility of potential renal findings. In the repeat study, both salt forms showed similar exposures during the dosing period, but renal tubular toxicity was observed only with MDV1634.MAL and not with MDV1634.2HCl. The renal findings with MDV1634.MAL included early urinary biomarker changes (increase in albumin, clusterin, ß2 microglobulin, and neutrophil gelatinase-associated lipocalin); elevations in serum blood urea nitrogen and creatinine; and microscopic findings of partially reversible tubular basophilia, single cell necrosis, pigmentation, and mineralization. The renal findings in contrast to the BP findings were MAL-specific and considered not related to MDV1634, thereby under scoring the importance of salt forms in pharmaceutical development.

Pharmacodynamic and pharmacokinetic investigation of cyclodextrin-mediated asenapine maleate in situ nasal gel for improved bioavailability.

Asenapine maleate (AM) is used in the treatment of schizophrenia. Its oral and sublingual bioavailability is <2% and 35%, respectively, due to first pass metabolism and poor solubility. To avoid first pass metabolism and to enhance solubility at all nasal pH conditions, thermo-responsive in situ nasal gel containing asenapine maleate-hydroxyl propyl ß cyclodextrin inclusion complex (AM-HPßCD) was prepared in the present study. Inclusion complex (1:1 molar ratio) was characterized using UV spectroscopy, FITR and XRD techniques. Selected formulation (F8b) contained a thermo-sensitive polymer poloxamer 407 which formed gel at 23%w/v concentration and a mucoadhesive polymer PVP K 30 (0.3%w/v) in temperature range of 29-34 °c. It was analyzed for pH, clarity, gelation temperature, mucoadhesive strength, gel strength and rheological parameters using Anton paar compact rheometer. This formulation was subjected to in vitro drug diffusion study using the Franz diffusion cell. Maximum % drug diffusion was obtained at the end of 120 min (99.1 ± 0.44%w/v). Dissolution in simulated nasal fluid was 92.33 ± 0.15%w/v at the end of 120 min. Locomotor activity was improved with nasal gel containing AM-HPßCD as compared to AM and AM-HPßCD oral solution in rats. Cmax for nasal gel was found to be more (9 ng/ml) as compared to AM-HPßCD (5.5 ng/mL) and oral standard solution (2 ng/ml). Tmax was found to be 1.5 h. AUC and thus bioavailability in rats by nasal route was increased by 2.5 fold.

Evaluation of the cytotoxicity, genotoxicity and mucus permeation capacity of several surface modified poly(anhydride) nanoparticles designed for oral drug delivery.

The main concerns with drugs designed for oral administration are their inactivation or degradation in the harsh conditions of the gastrointestinal tract, their poor solubility through the gastrointestinal mucus gel layer, the poor intestinal epithelium permeability that limits their absorption, and their toxicity. In this context, poly(anhydride) nanoparticles are capable of protecting the drug from the harsh environment, reduce the drug's toxicity and, by virtue of surface modification, to enhance or reduce their mucus permeability and the bioadhesion to specific target cells. The copolymer between methyl vinyl ether and maleic anhydride (commercialized as Gantrez® AN 119) are part of the poly(anhydride) nanoparticles. These biocompatible and biodegradable nanoparticles (NPs) can be modified by using different ligands. Their usefulness as drug carriers and their bioadhesion with components of the intestinal mucosa have been described. However, their toxicity, genotoxicity and mucus permeation capacity has not been thoroughly studied. The aim of this work was to evaluate and compare the in vitro toxicity, cell viability and in vitro genotoxicity of the bioadhesive empty Gantrez® AN 119 NPs modified with dextran, aminodextran, 2-hydroxypropyl-ß-cyclodextrin, mannosamine and poly-ethylene glycol of different molecular weights. Results showed that, in general, coated NPs exhibit better mucus permeability than the bare ones, those coated with mannosamine being the most permeable ones. The NPs studied did not affect cell metabolism, membrane integrity or viability of Caco-2 cells at the different conditions tested. Moreover, they did not induce a relevant level of DNA strand breaks and FPG-sensitive sites (as detected with the comet assay).

Pharmacokinetics of Maleic Acid as a Food Adulterant Determined by Microdialysis in Rat Blood and Kidney Cortex.

Maleic acid has been shown to be used as a food adulterant in the production of modified starch by the Taiwan Food and Drug Administration. Due to the potential toxicity of maleic acid to the kidneys, this study aimed to develop an analytical method to investigate the pharmacokinetics of maleic acid in rat blood and kidney cortex. Multiple microdialysis probes were simultaneously inserted into the jugular vein and the kidney cortex for sampling after maleic acid administration (10 or 30 mg/kg, i.v., respectively). The pharmacokinetic results demonstrated that maleic acid produced a linear pharmacokinetic phenomenon within the doses of 10 and 30 mg/kg. The area under concentration versus time curve (AUC) of the maleic acid in kidney cortex was 5-fold higher than that in the blood after maleic acid administration (10 and 30 mg/kg, i.v., respectively), indicating that greater accumulation of maleic acid occurred in the rat kidney.

Pharmacokinetics and bioavailability of oral single-dose maleic acid in biofluids of Sprague-Dawley rats.

Maleic acid (MA) was purposefully adulterated in an array of starch-based foods in Taiwan, inciting a food safety incident. Due to limited data on the pharmacokinetics and bioavailability of ingested MA, we studied pharmacokinetic (PK) parameters in serum and urine of Sprague Dawley rats. Three groups of male and female rats were given three doses of MA by oral gavage; biofluid samples were collected accordingly. Data demonstrated that a non-compartment model best described MA's linear kinetic behavior upon ingestion. The mean residence life of maleic acid in serum was 17.58 h and 9.84 h for low-dosed male and female rats, whereas 8.24 h and 4.17 h for high-dosed male and female rats, respectively. Our results revealed oral bioavailability ranged from 30.8 to 41.0% for males and 32.2-39.1% for females. The data confirmed that ingested MA is absorbed and metabolized rapidly, along with low bioavailability. Future pathological studies may determine whether prolonged and low-level exposures of MA produce nephrotoxicity. These data provide additional contribution to current understanding of the kinetics of MA in a rat model and enable the development of a physiologically based model, which is essential to form the basis of evidenced-based food safety guidelines.

Determination of the maleic acid in rat urine and serum samples by isotope dilution-liquid chromatography-tandem mass spectrometry with on-line solid phase extraction.

A rapid and simple on-line solid-phase extraction coupled with isotope dilution-liquid chromatography-tandem mass spectrometry (SPE-ID-LC-MS/MS) method was developed to quantitate maleic acid in serum and urine of SpragueDawley (SD) rats. The aforementioned biological samples were spiked with (13)C2-maleic acid, vigorously vortexed, added with acetonitrile to precipitate proteins, and then injected into the on-line SPE-LC-MS/MS system for quantification. Upon validation, this method demonstrated excellent feasibility and sensitivity: calibration curves for maleic acid in serum and urine display excellent linearity with the coefficient of determination (R(2)) greater than 0.999; the limits of detection and quantitation (LOD and LOQ) for maleic acid were determined at 0.2 and 0.5µg L(-1), respectively. Additionally, intra-day accuracy for maleic acid in serum and urine samples ranged from 94.0% to 100.2% and 101.3% to 104.4%, respectively. Furthermore, inter-day accuracy ranged from 93.6% to 101.0% and from 102.3% to 111.4% in serum and urine samples, respectively. Intra-day precision %RSD of maleic acid in serum and urine samples was 13.8% or less, whereas the inter-day precision was 6.1% or less. The matrix effects were not found to be statistically significant (p=0.9145 and p=0.5378, correspondingly) based on the calculations of recovery functions. The collected serum and urine samples were analyzed using SPE-ID-LC-MS/MS. Our results reveal trace levels of maleic acid in the control rats, demonstrating that this method is capable of analyzing background levels of contaminants in biofluids with excellent sensitivity and specificity at part-per-billion levels concentrations in complex matrices.

An in silico toxicogenomics approach for inferring potential diseases associated with maleic acid.

Maleic acid is a multi-functional chemical widely applied in the manufacturing of polymer products including food packaging. However, the contamination of maleic acid in modified starch has raised the concerns about the effects of chronic exposure to maleic acid on human health. This study proposed a novel toxicogenomics approach for inferring functions, pathways and diseases potentially affected by maleic acid on humans by using known interactions between maleic acid and proteins. Neuronal signal transmission and cell metabolism were identified to be most influenced by maleic acid in this study. The top disease categories inferred to be associated with maleic acid were mental disorder, nervous system diseases, cardiovascular diseases, and cancers. The results from the in silico analysis showed that maleic acid could penetrate the blood-brain barrier to affect the nervous system. Several functions and pathways were further analyzed and identified to give insights into the mechanisms of maleic acid-associated diseases. The toxicogenomics approach may offer both a better understanding of the potential risks of maleic-acid exposure to humans and a direction for future toxicological investigation.

Styrene-maleic acid copolymer-encapsulated CORM2, a water-soluble carbon monoxide (CO) donor with a constant CO-releasing property, exhibits therapeutic potential for inflammatory bowel disease.

Carbon monoxide (CO), the physiological product of heme oxygenase during catabolic breakdown of heme, has versatile functions and fulfills major anti-oxidative and anti-apoptotic roles in cell systems. Administration of CO is thus thought to be a reasonable therapeutic approach in diseases-such as inflammatory bowel disease-that are induced by reactive oxygen species (ROS). Tricarbonyldichlororuthenium(II) dimer (CORM2) is a commonly used CO donor, but it has poor aqueous solubility and a very short CO-releasing half-life (t1/2). In the present study, we prepared micelles consisting of water-soluble styrene-maleic acid copolymer (SMA) encapsulating CORM2 (SMA/CORM2) that had a hydrodynamic size of 165.3nm. Compared with free CORM2, SMA/CORM2 demonstrated better water solubility (>50mg/ml in a physiological water solution). Moreover, because of micelle formation in an aqueous environment, the CO release rate was slow and sustained. These properties resulted in much longer in vivo bioactivity of SMA/CORM2 compared with that of free CORM2, i.e. the t1/2 in blood of SMA/CORM2 in mice after intravenous (i.v.) injection was about 35 times longer than that of free CORM2. We then evaluated the therapeutic potential of SMA/CORM2 in a murine model of inflammatory colitis induced by dextran sulfate sodium (DSS). Administration (either i.v. or oral) of SMA/CORM2 once at the beginning of colitis, 3days after DSS treatment, significantly improved colitis symptoms-loss of body weight, diarrhea, and hematochezia-as well as histopathological colonic changes-shortening of the colon and necrosis or ulcers in the colonic mucosa. Up-regulation of inflammatory cytokines including monocyte chemotactic protein-1, tumor necrosis factor-α, and interleukin-6 in this DSS-induced colitis was significantly suppressed in SMA/CORM2-treated mice. SMA/CORM2 may thus be a superior CO donor and may be a candidate drug, which involves cytokine suppression, for ROS-related diseases including inflammatory bowel disease.

Ionic complexation as a non-covalent approach for the design of folate anchored rifampicin Gantrez nanoparticles.

The present study discloses the design of folate anchored Rifampicin-Poly methylvinylether maleic anhydride copolymer (Gantrez AN-119, Gantrez) nanoparticles (RFMGzFa) by ionic complexation. Folic acid was anchored to the preformed drug loaded nanoparticles. Folic acid was anchored in different concentration by simply varying the amount of folic acid added during preparation. RFMGzFa nanoparticles were prepared by emulsion solvent diffusion method. Gantrez AN-119 rapidly hydrolyzes in aqueous medium releasing carboxylic acid groups, to create an acidic environment. This facilitates protonation and subsequent ionic complexation of folic acid with the carboxylic groups, to enable anchoring. FTIR spectra confirmed this interaction. Infrared imaging revealed distribution of folic acid across the nanoparticle surface. Nanoparticles were obtained in the size range 350-450 nm with RFM loading of 12-14% w/w. Zeta potential confirmed colloidal stability. TEM/SEM revealed spherical morphology. RFMGzFa nanoparticles exhibited sustained release of RFM and folic acid. Folic acid showed sustained release upto 12 h, which was ion exchange mediated. A 480% enhancement in RFM uptake with RFMGzFa nanoparticles compared to 300% with RFMGz nanoparticles in-vitro, in human macrophage cell line U-937, suggested the role of folic acid in folate receptor mediated uptake. Ionic complexation represents a simple non-covalent approach for anchoring folic acid on polymeric nanoparticles of Gantrez.

Pharmacokinetic comparison of the maleate and free base formulations of LB80380, a novel nucleotide analog, in healthy male volunteers.

OBJECTIVE: LB80380, a dipivoxil ester prodrug of LB80331, is a novel antiviral agent for the treatment of chronic hepatitis B. The aim of this study was to compare the pharmacokinetic differences after single oral administrations of the free base and maleate formulations of LB80380 in healthy male subjects. METHODS: An open-label, single- dose, randomized-sequence, 2-treatment crossover study was conducted in 32 Korean male volunteers. Subjects received either a combination of 60 and 90 mg tablets of the free base LB80380 formulation or a 183 mg (150 mg as a free base) tablet of the maleate LB80380 formulation. Then, after a 14- day washout period, each subject received the other formulation. Plasma and urine concentrations of LB80331 and LB80317 (active metabolites of LB80380) were measured by validated liquid chromatographytandem mass spectrometry assays. A safety assessment, which included vital signs, adverse events, electrocardiograms and clinical laboratory tests, was performed for each subject. RESULTS: A total of 32 healthy subjects was enrolled, and 26 subjects completed the study. Single oral administrations of LB80380 maleate tablets did not result in clinically significant differences in the safety profile compared to the LB80380 free base tablets. The 90% confidence intervals (CIs) for the geometric mean ratios of Cmax and AUClast for LB80331 of the two treatments (maleate versus free base formulation) were 0.986 - 1.1240 and 0.9848 - 1.0533, respectively. The 90% CIs for the geometric mean ratios of Cmax and AUClast for LB80317 were 0.8379 - 0.9696 and 0.7224 - 0.9196. CONCLUSIONS: In healthy male subjects, the 183 mg LB80380 maleate tablet was pharmacokinetically equivalent to the 60 and 90 mg LB80380 free base tablets.

Intracellular uptake and behavior of two types zinc protoporphyrin (ZnPP) micelles, SMA-ZnPP and PEG-ZnPP as anticancer agents; unique intracellular disintegration of SMA micelles.

SMA-ZnPP and PEG-ZnPP are micellar drugs, encapsulating zinc protoporphyrin IX (ZnPP) with styrene maleic acid copolymer (SMA) and covalent conjugate of ZnPP with polyethylene glycol (PEG) respectively. Their intracellular uptake rate and subcellular localization were investigated. We found SMA-ZnPP showed higher and more efficient (about 2.5 times) intracellular uptake rate than PEG-ZnPP, although both SMA-ZnPP and PEG-ZnPP micelles were localized at endoplasmic reticulum (ER) and inhibited the target enzyme heme oxygenase 1 (HO-1) similarly. Both micellar ZnPP were taken up into the tumor cells by endocytosis. Furthermore SMA-ZnPP and PEG-ZnPP were examined for their drug releasing mechanisms. Liberation of ZnPP from the SMA micelle appears to depend on cellular amphiphilic components such as lecithin, while that for PEG-ZnPP depends on hydrolytic cleavage. These results indicate that these micelle formulations make water insoluble ZnPP to water soluble practical anticancer agents.

Quantification of henatinib maleate, a novel potent inhibitor of VEGF receptors, in rat plasma by LC-MS/MS.

Henatinib maleate (R,Z)-2-[(5-fluoro-1,2-dihydro-2-oxo-3H-indol-3-ylidene) methyl]-5-(2-hydroxy-3-morpholinopropyl)-3-methyl-5,6,7,8-tetrahydro-1H-pyrrolo[3,2-c] azepin-4-ketone maleate is a potent inhibitor of vascular endothelial growth factor receptors, and is currently under preclinical evaluation as an anticancer drug. A novel method for the quantification of henatinib maleate in rat plasma using high performance liquid chromatography-tandem mass spectrometry has been developed. The analyte (henatinib maleate) and internal standard (papaverine hydrochloride) were extracted from 50 microL of rat plasma by protein precipitation and separated on a C(18) column using a mixture of 25 mm ammonium acetate buffer : methanol : acetonitrile (35 : 50 : 15, v/v/v) as mobile phase with a run time of 4.5 min. The detection was performed by means of triple quadrupole mass spectrometer equipped with an ESI interface operating in the multiple-reaction monitoring mode. A linear response was observed over the concentration range 5.0-1000 ng/mL. The limit of quantification was 5.0 ng/mL. Both intra- and inter-day precision, defined as relative standard deviation, were within 9.7%. Accuracy, defined as relative error, was within +/- 3.1%. The developed method was successfully applied to preclinical pharmacokinetic studies of henatinib maleate in rat after a single oral administration of the drug.