Development and validation of a new UPLC-MS/MS method for quantification of ganoderic acid-A loaded nanolipidic carrier in rat plasma and application to pharmacokinetic studies.

A systematic methodology was used to quantify ganoderic acid-A (GA-A) loaded nano-lipid carriers (NLC) in rat plasma using UPLC-MS/MS. Separation of the analyte was achieved using ACQUITY UPLC BEH C18 column (1.7 µm) and mobile phase as water containing 0.1% Acetonitrile (40: 60% v/v) at a flow rate of 0.4 mL·min-1. The analyte was detected using MRM mode to track precursor-to-product ion transitions of 515.37 â†’ 285.31 m/z (time scan of 2 min) for GA-A, and 175.11 â†’ 115.08 m/z (time scan of 4 min) for ascorbic acid as an internal standard (IS), respectively. The developed method was validated for linearity, accuracy, within and between day precisions, limit of quantification and recovery of the analyte. The results indicated intra and inter-day consistency and precision values were found to be within the acceptance limit for the plasma samples. The method applicability for determination of pharmacokinetic parameters of GA-A was assessed after oral administration of free GA-A solution and GA-A-loaded NLC, which indicated significant difference (p < 0.05) in the rate and extent of absorption parameters of GA-A from the NLC formulation vis-à-vis the plain solution. Overall, the studies construed successful development and application of UPLC-MS/MS method for estimation of GA-A in the lipidic formulation.

Ganoderic Acid A Targeting ß-Catenin in Wnt Signaling Pathway: In Silico and In Vitro Study.

Wnt signaling pathways are the group of signaling transduction controlling the embryonic development, cell proliferation, cell migration, cell fate specification, and body axis pattern. Nuclear accumulation of ß-catenin in Wnt signaling is a widely recognized marker of poor cancer prognosis which regulates fat and glucose metabolism. Ganoderic acid is a triterpene isolated from fungus Ganoderma lucidum renowned for its pharmacological effects. The present study revealed the mechanistic study of ß-catenin with 50 isoforms of ganoderic acid by molecular docking using Maestro 9.6 (Schrödinger Inc) in Wnt signaling pathway. Molecular docking reveals the binding interaction of ß-catenin and ganoderic acid A with GScore (-9.44), kcal/mol, lipophilic EvdW (-2.86), electro (-0.72), Glide emodel (-50.401), MM-GBSA (-87.441), H bond (-1.91) with Lys 180 and Asn 220 residues involved in hydrogen bonding. Qikprop analyzed the absorption, distribution, metabolism, excretion, and toxicity and confirmed that most of the isoforms satisfies Lipinski rule but needs little modifications in their structure. The ganoderic acid A is the best-docked isoforms which inhibits the proliferation, viability, and intracellular ROS of pancreatic cancer RIN-5F cells in a dose-dependent manner.

Hepatic fatty acid profile of rats fed a triheptanoin-based ketogenic diet / Perfil de ácidos grasos de hígados de ratones alimentados con una dieta cetogénica basada en triheptanoína

Objective: the aim of this study was to evaluate the influence of consumption of a ketogenic diet supplemented with triheptanoin, a medium-chain anaplerotic triacylglycerol, on the liver fatty acid profile of Wistar rats. Methods: three groups of male Wistar rats (n=10) were submitted to an AIN-93 control diet, a triheptanoin-based ketogenic diet, or a soybean oil-based ketogenic diet for 60 days. Excised livers were subjected to lipid extraction and methylation to obtain fatty acids methyl esters, which were subjected to gas chromatography-mass spectrometry. Results and discussion: compared to the rats fed the control diet, those fed ketogenic diets showed a significant reduction in the concentrations of 9-hexadecenoic and 9-octadecenoic acids, whereas those fed triheptanoin showed increased levels of octadecanoic acid. Conclusion: changes in the liver fatty acid profiles of the rats fed a triheptanoin-based or a soybean oil-based ketogenic diet did not seem to be related to the dietary fat source, but rather to the characteristics of the ketogenic diets themselves (AU)

Objetivo: el objetivo de este estudio fue evaluar la influencia del consumo de una dieta cetogénica complementada con triheptanoína, un triacilglicerol de cadena media y anaplerótico, en el perfil de ácidos grasos del hígado de ratones Wistar. Métodos: tres grupos de ratones Wistar machos (n=10) fueron sometidos durante 60 días a una dieta AIN-93 de control, una dieta cetogénica basada en triheptanoína o una dieta cetogénica a base de aceite de soja. Los hígados fueron escindidos y sometidos a extracción de lípidos y metilación para obtener los ésteres metílicos de ácidos grasos, que se sometieron a cromatografía de gas-espectrometría de masa. Resultados y discusión: en comparación con los ratones alimentados con la dieta de control, los de ambas dietas cetogénicas mostraron una reducción significativa en las concentraciones de los ácidos grasos 9-hexadecenoico y 9-octadecenoico, mientras que los alimentados con triheptanoína mostraron niveles de ácido octadecenoico aumentados. Conclusión: los cambios en los perfiles de ácidos grasos del hígado de los ratones alimentados con dietas cetogénicas no están relacionados con la fuente de grasa de la dieta (triheptanoína o aceite de soja), sino más bien con la concentración total de lípidos (AU)

Effects of carbohydrate polymers in self-microemulsified tablets on the bioavailability of atorvastatin: In vitro-in vivo study.

AIMS: The concentrations of crospovidone (CP), maltodextrin and microcrystalline cellulose (MCC) have been optimized in the development of self-microemulsified tablets (SMET) to improve the oral bioavailability of an anti-hyperlipidemic drug, atorvastatin, and the in-vivo pharmacokinetic parameters of the optimized SMET were compared with those of a commercial tablet in rabbits. MAIN METHODS: Self microemulsified liquids (SELS) were prepared with oleic acid, Span 40 and Tween 80. SELS were converted into SMET by adsorption, followed by compression using factors such as CP, maltodextrin and MCC, which were optimized through a 2(3)-factorial design considering responses such as the disintegration time and, the times for 50% and 80% of the drug to be released. KEY FINDINGS: The results indicated that CP and MCC were inversely related to the responses, while maltodextrin was directly related to the responses. The droplet size of the disintegrated SMET oil globules was within 2.73 to 4.77 µm. The Cmax and AUC0-∞ of the optimized SMET were found to be 32.5% and 38.8% higher, respectively, than those of the commercial tablet. SIGNIFICANCE: The present results indicate that the bioavailability of the SMET of atorvastatin is better than the commercial formulation.

Pharmacokinetic Drug-Drug Interaction Study Between Raltegravir and Atorvastatin 20 mg in Healthy Volunteers.

BACKGROUND: Dyslipidemia is highly prevalent among patients with HIV infection and contributes to an increased risk of cardiovascular disease. We investigated the influence of a frequently used statin, atorvastatin, on the pharmacokinetics of the HIV-integrase inhibitor raltegravir and vice versa. METHODS: Open-label, crossover 3-period phase I trial in 24 healthy volunteers. Subjects took raltegravir 400 mg two times a day for 7 days, atorvastatin 20 mg once a day for 7 days, and the combination of atorvastatin 20 mg once a day + raltegravir 400 mg two times a day for 7 days with 2-week washout periods in between. Intensive steady-state 12- and 24-hour pharmacokinetic blood sampling was performed. Geometric mean ratios of the test treatment (combination raltegravir + atorvastatin) versus the reference treatment (raltegravir or atorvastatin alone) and 90% confidence intervals were calculated for the area under the plasma concentration-time curve (AUC). Fasting lipid profiles were obtained to assess short-term lipid-lowering effect of atorvastatin with or without concomitant raltegravir use. RESULTS: Twenty-four healthy volunteers (11 males) were enrolled. All but 1 subject completed the trial, and no serious adverse events were reported. Geometric mean ratios (90% confidence interval) were 1.01 (0.68-1.51) for raltegravir AUC(0-12h) and 1.00 (0.90-1.11) for atorvastatin AUC(0-24h). The AUC(0-24h) metabolite-to-parent ratio for atorvastatin lactone, ortho-hydroxy, and para-hydroxy atorvastatin did not change during concomitant raltegravir use. The effect of atorvastatin on low-density lipoprotein cholesterol was not significantly different when combined with raltegravir versus atorvastatin alone (P = 0.638). CONCLUSIONS: Atorvastatin 20 mg has no clinically relevant effect on the pharmacokinetics of raltegravir and vice versa. The combination was well tolerated and can be administered without dose adjustments.

[Choosing wisely when prescribing statins]. / Verstandig kiezen bij het voorschrijven van statinen.

The Dutch campaign 'Verstandig kiezen', based on the American programme 'Choosing wisely', aims to improve quality in healthcare, with attention to cost control. The 'Choosing wisely'-based programme can be applied in the choice of a statin. Atorvastatin and rosuvastatin are regarded as equal choices in various guidelines regarding cardiovascular risk management. Generic atorvastatin is available, and is approximately 25 times cheaper than rosuvastatin in almost equipotent doses. Rosuvastatin provides a greater LDL reduction than atorvastatin. Patient LDL targets can usually be achieved with atorvastatin, and rosuvastatin is not needed. At group level, there are no relevant differences in adverse-events profile between both statins. Atorvastatin and rosuvastatin do have different pharmacokinetic interactions. When changing medication, good provision of information is a prerequisite for patient satisfaction and compliance. We advise use of atorvastatin instead of rosuvastatin as drug of choice when the LDL target is not reached using simvastatin. However, under specific conditions, rosuvastatin should be the treatment of choice. Efficacy and adverse effects should then be evaluated at individual patient level.

Bioequivalence Study of Atorvastatin Tablets in Healthy Pakistani Volunteers.

A two way, randomized cross-over bioequivalence study was conducted to analyse the rate and extent of absorption of atorvastatin after a single dose of 80 mg atorvastatin as atorvastatin calcium tablets. The study was carried out using healthy male volunteers (N = 24). A high performance liquid chromatography method was employed to determine the level of drug in human plasma. It was concluded that the test and the reference drug exhibited comparable values of pharmacokinetic parameters. It was also concluded that since there was no significant difference between the rate and extent of absorption of the drug from the test and the reference formulations: these two formulations could thus be declared bioequivalent.

Effect of concomitant icosapent ethyl (eicosapentaenoic acid ethyl ester) on the pharmacokinetics of atorvastatin.

BACKGROUND AND OBJECTIVE: Icosapent ethyl is a high-purity prescription form of eicosapentaenoic acid ethyl ester approved as an adjunct to diet to reduce triglyceride levels in adult patients with triglyceride levels ≥500 mg/dL (≥5.65 mmol/L). The objective of this open-label, drug-drug interaction study was to examine the effects of icosapent ethyl on the steady-state pharmacokinetics of atorvastatin, a commonly prescribed medication in patients with dyslipidaemia. METHODS: Thirty healthy subjects received atorvastatin 80 mg/day on days 1-7, icosapent ethyl 4 g/day on days 8-28, and co-administration on days 29-35. Primary end-points were natural log-transformed maximum plasma concentration (C(max)) and area under the concentration-versus-time curve from 0 to 24 h (AUC(0-24)) for atorvastatin, 2-hydroxyatorvastatin, and 4-hydroxyatorvastatin with and without icosapent ethyl. RESULTS: Of the 30 subjects enrolled, 26 completed the study. The 90% confidence intervals for C(max) and AUC(0-24) least-squares geometric mean ratios were within the 0.80-1.25 bounds. Concomitant administration of icosapent ethyl and atorvastatin was safe and well tolerated and icosapent ethyl did not significantly change the steady state C(max) and AUC(0-24) of atorvastatin, 2-hydroxyatorvastatin, or 4-hydroxyatorvastatin. CONCLUSIONS: At steady-state concentrations, icosapent ethyl did not have an effect on the pharmacokinetics of atorvastatin. Co-administration of icosapent ethyl and atorvastatin was safe and well tolerated in healthy adult subjects.

LDL cholesterol variability in patients with Type 2 diabetes taking atorvastatin and simvastatin: a comparison of two formulae for LDL-C estimation.

BACKGROUND: A new formula was recently proposed by Cordovo et al. that was more highly correlated with low-density lipoprotein (LDL) measured directly than the Friedewald LDL formula. We conducted this prospective study to establish whether the new formula allows true variations in LDL within the same individual to be tracked more closely than that of the Friedewald formula. METHODS: A cross-over study of biological variation of lipids in 26 patients with Type 2 diabetes (T2DM) taking either a short half-life statin, simvastatin 40 mg (n=10), or a long half-life statin, atorvastatin 10 mg. After three months on one statin, fasting lipids were measured on 10 occasions over a five-week period. The same procedure was then followed for the other statin. The LDL was measured by a direct LDL immunoassay and was compared to the LDL estimated by the Friedewald and Cordova (0.7516) × (total cholesterol [TC]-high-density lipoprotein cholesterol [HDL-C]) formulae. RESULTS: As a group, the calculated or measured mean LDL was no different between statins. However, the biological coefficient of variation (CV) of directly measured LDL was far larger with simvastatin than atorvastatin. This difference was detected by Cordova LDL but not found with the Friedewald LDL formula. CONCLUSIONS: In contrast to Friedewald LDL, Cordova LDL estimation revealed LDL to be much more stable in T2DM patients taking atorvastatin rather than simvastatin that was in accord with LDL when measured directly. Therefore, Cordova LDL which is a measure of non-HDL-cholesterol is the simplest, cheapest and the most convenient measurement for assessment of response to statin treatment.

Preparation and evaluation of solid dispersion of atorvastatin calcium with Soluplus® by spray drying technique.

The aim of the present study was to investigate the effect of Soluplus® on the solubility of atorvastatin calcium and to develop a solid dispersion formulation that can improve the oral bioavailability of atorvastatin calcium. We demonstrated that Soluplus® increases the aqueous solubility of atorvastatin calcium. Several solid dispersion formulations of atorvastatin calcium with Soluplus® were prepared at various drug : carrier ratios by spray drying. Physicochemical analysis demonstrated that atorvastatin calcium is amorphous in each solid dispersion, and the 2 : 8 drug : carrier ratio provided the highest degree of sustained atorvastatin supersaturation. Pharmacokinetic analysis in rats revealed that the 2 : 8 dispersion significantly improved the oral bioavailability of atorvastatin. This study demonstrates that spray-dried Soluplus® solid dispersions can be an effective method for achieving higher atorvastatin plasma levels.

Efficacy, safety, tolerability, and pharmacokinetic profile of evacetrapib administered as monotherapy or in combination with atorvastatin in Japanese patients with dyslipidemia.

The cholesteryl ester transfer protein (CETP) inhibitor evacetrapib has been previously shown to increase high-density lipoprotein cholesterol (HDL-C) and decrease low-density lipoprotein cholesterol (LDL-C) levels, as monotherapy or in combination with statins. In this study, 165 Japanese patients with elevated LDL-C or low HDL-C levels were randomly assigned to receive placebo, evacetrapib monotherapy 30 mg, 100 mg, or 500 mg, atorvastatin 10 mg, or evacetrapib 100 mg in combination with atorvastatin 10 mg. After 12 weeks, evacetrapib monotherapy increased HDL-C levels by 74%, 115%, and 136% and decreased LDL-C levels by 15%, 23%, and 22% and CETP activity by 50%, 83%, and 95% (for the 30-mg, 100-mg, and 500-mg dose groups, respectively) versus placebo. In combination with atorvastatin 10 mg, evacetrapib 100 mg increased HDL-C levels by 103% and decreased LDL-C levels by 15% and CETP activity by 68% versus atorvastatin alone. After a 4- to 6-week washout, HDL-C, LDL-C, and CETP mass and activity returned to baseline levels in the evacetrapib-treated groups, and most patients had evacetrapib concentrations below the quantitation limit. Evacetrapib monotherapy or in combination with atorvastatin was not likely to be associated with any significant change in blood pressure and did not have any adverse effects on mineralocorticoid or glucocorticoid measures. Notably, plasma evacetrapib concentrations were mostly undetectable, and all pharmacodynamic biomarkers (HDL-C and LDL-C levels and CETP mass and activity) returned to baseline after a 4- to 6-week washout. In conclusion, evacetrapib as monotherapy or in combination with atorvastatin effectively decreased CETP activity and LDL-C levels and increased HDL-C levels after 12 weeks in Japanese patients with dyslipidemia.

Investigation of combined CYP3A4 inductive/inhibitory properties by studying statin interactions: a model study with the renin inhibitor ACT-178882.

PURPOSE: ACT-178882, a direct renin inhibitor, was used as a model compound in an elaborate drug-drug interaction study with atorvastatin and simvastatin to explore complex CYP3A4 inductive and inhibitory properties. METHODS: Thirty-two healthy male subjects received single doses of 20 mg atorvastatin and 20 mg simvastatin on days 1, 9, 31, and 41. On days 6 to 33, 500 mg ACT-178882 was administered once daily. Plasma concentrations of ACT-178882, simvastatin, and atorvastatin were measured by LC-MS/MS. Routine safety assessments were performed throughout the study. RESULTS: Exposure (as based on area under the curve) to simvastatin and 6ß-hydroxyacid simvastatin increased (90 % confidence interval) 4.63-fold (3.90, 5.50) and 3.71-fold (3.19, 4.32), respectively, when comparing day 9 and day 1. On day 9, exposure to atorvastatin was similar but Cmax decreased, while both variables decreased for ortho-hydroxy atorvastatin when compared to day 1. On day 31, after prolonged administration of ACT-178882, exposure to atorvastatin, ortho-hydroxy atorvastatin, simvastatin, and 6ß-hydroxyacid simvastatin decreased by 14, 19, 21, and 27 %, respectively, when compared to day 9. However, on this day, exposure to simvastatin and its metabolite was still markedly higher when compared to day 1. Effects of ACT-178882 had largely dissipated on day 41. CONCLUSIONS: This design enabled the study of complex time-dependent effects on CYP3A4 activity with clinically relevant substrates.

Prediction of clinical irrelevance of PK differences in atorvastatin using PK/PD models derived from literature-based meta-analyses.

To support the development of a fixed-dose combination (FDC) of ezetimibe and atorvastatin for the treatment of dyslipidemia, bioequivalence (BE) studies were conducted across a combined dose range (10/10, 10/20, 10/40, and 10/80 mg of ezetimibe/atorvastatin). In the BE trials, all parameters met traditional BE bounds except for atorvastatin peak plasma concentration (Cmax) at two intermediate doses. Literature-based metadata analysis predicted that the observed difference in Cmax between an ezetimibe+atorvastatin FDC and coadministration of these agents translates directly into a non-clinically significant change of <1.2% absolute difference in the percentage lowering of low-density-lipoprotein cholesterol . Both FDC doses were confirmed to be clinically equivalent to coadministration in the subsequent clinical equivalence trials. These data suggest that modeling of dose-response relationships may be useful in predicting clinical equivalence, lowering cost/timelines through effective powering of studies, and predicting the effectiveness of new dosage formulations without the need for additional clinical efficacy trials in regulatory settings.

Formulation and evaluation of fixed-dose combination of bilayer gastroretentive matrix tablet containing atorvastatin as fast-release and atenolol as sustained-release.

The objective of the present study was to develop bilayer tablets of atorvastatin and atenolol that are characterized by initial fast-release of atorvastatin in the stomach and comply with the release requirements of sustained-release of atenolol. An amorphous, solvent evaporation inclusion complex of atorvastatin with ß -cyclodextrin, present in 1 : 3 (drug/cyclodextrin) molar ratio, was employed in the fast-release layer to enhance the dissolution of atorvastatin. Xanthan gum and guar gum were integrated in the sustained-release layer. Bilayer tablets composed of sustained-release layer (10% w/w of xanthan gum and guar gum) and fast-release layer [1 : 3 (drug/cyclodextrin)] showed the desired release profile. The atorvastatin contained in the fast-release layer showed an initial fast-release of more than 60% of its drug content within 2 h, followed by sustained release of the atenolol for a period of 12 h. The pharmacokinetic study illustrated that the fast absorption and increased oral bioavailability of atorvastatin as well as therapeutic concentration of atenolol in blood were made available through adoption of formulation strategy of bilayer tablets. It can be concluded that the bilayer tablets of atorvastatin and atenolol can be successfully employed for the treatment of hypertension and hypercholesterolemia together through oral administration of single tablet.

Atorvastatin suppresses Toll-like receptor 4 expression and NF-κB activation in rabbit atherosclerotic plaques.

BACKGROUND: Toll-like receptor 4 (TLR4) plays an essential role in the pathogenesis and progression of atherosclerosis, which overexpresses in atherosclerotic lesions and mediates the production of inflammatory factors. The aim of this study was to investigate the effects of atorvastatin on TLR4 protein and mRNA expression and its downstream factor NF-κB activation in rabbit atherosclerotic plaques. MATERIALS AND METHODS: Rabbits continuously fed with high-fat diet for 24 weeks were randomly divided into two groups, the drug-treated group orally administrated with atorvastatin (2 mg/kg/day) three weeks after high-fat diet feeding and the model group with no treatment. The expression of TLR4 protein and mRNA, the level of activated NF-κB (p65) were respectively detected by western blotting, quantitative RT-PCR, and ELISA. RESULTS: The results showed that atorvastatin treatment reduced the expression of TLR4 protein and mRNA by 24.1% (p < 0.05) and 46.9% (p < 0.01), respectively, and also inhibited NF-κB activation by 76.0% (p < 0.001) in the atherosclerotic plaques. CONCLUSIONS: Thus, it was suggested that atorvastatin could exert an anti-atherosclerotic activity besides inhibiting cholesterol biosynthesis.

BSA nanoparticle loaded atorvastatin calcium--a new facet for an old drug.

BACKGROUND: Currently, the discovery of effective chemotherapeutic agents poses a major challenge to the field of cancer biology. The present study focuses on enhancing the therapeutic and anti cancer properties of atorvastatin calcium loaded BSA (ATV-BSA) nanoparticles in vitro. METHODOLOGY/RESULTS: BSA-ATV nanoparticles were prepared using desolvation technique. The process parameters were optimized based on the amount of desolvating agent, stabilization conditions as well as the concentration of the cross linker. The anti cancer properties of the protein coated ATV nanoparticles were tested on MiaPaCa-2 cell lines. In vitro release behavior of the drug from the carrier suggests that about 85% of the drug gets released after 72 hrs. Our studies show that ATV-BSA nanoparticles showed specific targeting and enhanced cytotoxicity to MiaPaCa-2 cells when compared to the bare ATV. CONCLUSION: We hereby propose that the possible mechanism of cellular uptake of albumin bound ATV could be through caveolin mediated endocytosis. Hence our studies open up new facet for an existing cholesterol drug as a potent anti-cancer agent.

Impact of switching treatment from rosuvastatin to atorvastatin on rates of cardiovascular events.

BACKGROUND: Now that generic atorvastatin has become available, a process of switching from rosuvastatin to atorvastatin may occur and could persist until the patent on branded rosuvastatin expires. It is important to understand the impact that such therapy may have on patients' cardiovascular (CV) health. OBJECTIVES: This simulated study estimates the impact of switching patients treated with rosuvastatin to atorvastatin on rates of CV events over a 5-year period. METHODS: A study of 50,038 virtual dyslipidemic patients aged 45 to 70 years was conducted using the Archimedes model. Virtual patients were created based on the profiles of patients in the National Health and Nutrition Examination Survey (NHANES). Statin treatment models were constructed based on data from published studies, including STELLAR, JUPITER, CARDS, ASCOT, and TNT. Patients were started on a dose of rosuvastatin based on their ATP III low-density lipoprotein cholesterol (LDL-C) goal and the distributions of statin use observed in US pharmacy claims data. Patients were monitored for 5 years, during which time they received regular visits with the opportunity to increase their dosage if they were above their LDL-C goal. In the experimental arm, patients were switched from rosuvastatin to atorvastatin at the first clinic visit 6 weeks after initiating rosuvastatin (using an atorvastatin dose twice the rosuvastatin milligram-dose). No switching occurred in the control arm, and patients were titrated as necessary per ATP III cholesterol management guidelines. The rate of first occurrence of a major adverse cardiovascular event (MACE; myocardial infarction, stroke, and/or cardiovascular-related death) over the 5-year period was estimated for each study arm. RESULTS: After 5 years, in the atorvastatin-switched arm compared with continuing rosuvastatin, 4.8% fewer patients reached goal (87% vs 91%, respectively). The 5-year relative risk for MACE with switching was 1.109 (95% CI, 1.092-1.127), and the number needed to harm (NNH) to incur 1 additional MACE over 5 years was 262, favoring treatment with rosuvastatin. In diabetic individuals who were switched to atorvastatin, the 5-year relative risk for MACE was 1.121 (95% CI, 1.091-1.151), and the NNH over 5 years was 195, indicating greater risk in diabetic individuals. The results were insensitive to adherence rates and LDL-C goal values. CONCLUSIONS: This study found that switching from rosuvastatin to atorvastatin led to fewer patients attaining LDL-C goal and a greater risk for MACE.

Hypoxia/reoxygenation stress signals an increase in organic anion transporting polypeptide 1a4 (Oatp1a4) at the blood-brain barrier: relevance to CNS drug delivery.

Cerebral hypoxia and subsequent reoxygenation stress (H/R) is a component of several diseases. One approach that may enable neural tissue rescue after H/R is central nervous system (CNS) delivery of drugs with brain protective effects such as 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (i.e., statins). Our present in vivo data show that atorvastatin, a commonly prescribed statin, attenuates poly (ADP-ribose) polymerase (PARP) cleavage in the brain after H/R, suggesting neuroprotective efficacy. However, atorvastatin use as a CNS therapeutic is limited by poor blood-brain barrier (BBB) penetration. Therefore, we examined regulation and functional expression of the known statin transporter organic anion transporting polypeptide 1a4 (Oatp1a4) at the BBB under H/R conditions. In rat brain microvessels, H/R (6% O2, 60 minutes followed by 21% O2, 10 minutes) increased Oatp1a4 expression. Brain uptake of taurocholate (i.e., Oap1a4 probe substrate) and atorvastatin were reduced by Oatp inhibitors (i.e., estrone-3-sulfate and fexofenadine), suggesting involvement of Oatp1a4 in brain drug delivery. Pharmacological inhibition of transforming growth factor-ß (TGF-ß)/activin receptor-like kinase 5 (ALK5) signaling with the selective inhibitor SB431542 increased Oatp1a4 functional expression, suggesting a role for TGF-ß/ALK5 signaling in Oatp1a4 regulation. Taken together, our novel data show that targeting an endogenous BBB drug uptake transporter (i.e., Oatp1a4) may be a viable approach for optimizing CNS drug delivery for treatment of diseases with an H/R component.

The effect of CYP3A4*1G allele on the pharmacokinetics of atorvastatin in Chinese Han patients with coronary heart disease.

The present study aimed to evaluate the impact of CYP3A4*1G allele on the pharmacokinetics of atorvastatin in the Chinese Han patients with coronary heart disease (CHD). Twenty male patients of CHD with different CYP3A4*1G genotypes were orally administered a single 20 mg dose of atorvastatin. Plasma concentrations of atorvastatin and 2-hydroxyatorvastatin were measured by high-performance liquid chromatography tandem mass spectrometry. The mean area under the plasma concentration-time curve from 0 to infinity (AUC0-∞ ) of atorvastatin in subjects with the CYP3A4*1G/*1G genotype were 36% or 25% lower than in those with the wild-type or the *1/*1G genotype, respectively. The time to peak plasma concentration (Tmax ) and oral clearance of atorvastatin (CL/F) were significantly different between subjects with the CYP3A4*1G/*1G genotype and the wild-type. The AUC0-∞ for 2-hydroxyatorvastatin in subjects with the CYP3A4*1G/*1G genotype was 44% or 31% lower than in those with the wild-type or the *1/*1G genotype, respectively. The peak plasma concentration, Tmax and apparent clearance of 2-hydroxyatorvastatin (CL/Fm) were significantly different between subjects with the CYP3A4*1G/*1G genotype and the wild-type. This study indicates that the CYP3A4*1G allele is associated with the pharmacokinetics of atorvastatin and its metabolites in those Chinese Han patients with CHD after a single oral dose.

Utility of Oatp1a/1b-knockout and OATP1B1/3-humanized mice in the study of OATP-mediated pharmacokinetics and tissue distribution: case studies with pravastatin, atorvastatin, simvastatin, and carboxydichlorofluorescein.

Although organic anion transporting polypeptide (OATP)-mediated hepatic uptake is generally conserved between rodents and humans at a gross pharmacokinetic level, the presence of three major hepatic OATPs with broad overlap in substrate and inhibitor affinity, and absence of rodent-human orthologs preclude clinical translation of single-gene knockout/knockin findings. At present, changes in pharmacokinetics and tissue distribution of pravastatin, atorvastatin, simvastatin, and carboxydichlorofluorescein were studied in oatp1a/1b-knockout mice lacking the three major hepatic oatp isoforms, and in knockout mice with liver-specific knockin of human OATP1B1 or OATP1B3. Relative to wild-type controls, oatp1a/1b-knockout mice exhibited 1.6- to 19-fold increased intravenous and 2.1- to 115-fold increased oral drug exposure, due to 33%-75% decreased clearance, 14%-60% decreased volume of distribution, and ≤74-fold increased oral bioavailability, with the magnitude of change depending on the contribution of oatp1a/1b to pharmacokinetics. Hepatic drug distribution was 4.2- to 196-fold lower in oatp1a/1b-knockout mice; distributional attenuation was less notable in kidney, brain, cardiac, and skeletal muscle. Knockin of OATP1B1 or OATP1B3 partially restored control clearance, volume, and bioavailability values (24%-142% increase, ≤47% increase, and ≤77% decrease vs. knockout, respectively), such that knockin pharmacokinetic profiles were positioned between knockout and wild-type mice. Consistent with liver-specific humanization, only hepatic drug distribution was partially restored (1.3- to 6.5-fold increase vs. knockout). Exposure and liver distribution changes in OATP1B1-humanized versus knockout mice predicted the clinical impact of OATP1B1 on oral exposure and contribution to human hepatic uptake of statins within 1.7-fold, but only after correcting for human/humanized mouse liver relative protein expression factor (OATP1B1 = 2.2, OATP1B3 = 0.30).