Lovastatin Acid Research Articles

Structural Analysis, Multi-Conformation Virtual Screening and Molecular Simulation to Identify Potential Inhibitors Targeting pS273R Proteases of African Swine Fever Virus.

The African Swine Fever virus (ASFV) causes an infectious viral disease in pigs of all ages. The development of antiviral drugs primarily aimed at inhibition of proteases required for the proteolysis of viral polyproteins. In this study, the conformation of the pS273R protease in physiological states were investigated, virtually screened the multi-protein conformation of pS273R target proteins, combined various molecular docking scoring functions, and identified five potential drugs from the Food and Drug Administration drug library that may inhibit pS273R. Subsequent validation of the dynamic interactions of pS273R with the five putative inhibitors was achieved using molecular dynamics simulations and binding free energy calculations using the molecular mechanics/Poison-Boltzmann (Generalized Born) (MM/PB(GB)SA) surface area. These findings demonstrate that the arm domain and Thr159-Lys167 loop region of pS273R are significantly more flexible compared to the core structural domain, and the Thr159-Lys167 loop region can serve as a "gatekeeper" in the substrate channel. Leucovorin, Carboprost, Protirelin, Flavin Mononucleotide, and Lovastatin Acid all have Gibbs binding free energies with pS273R that were less than -20 Kcal/mol according to the MM/PBSA analyses. In contrast to pS273R in the free energy landscape, the inhibitor and drug complexes of pS273R showed distinct structural group distributions. These five drugs may be used as potential inhibitors of pS273R and may serve as future drug candidates for treating ASFV.

Preclinical Pharmacokinetics and Pharmacodynamics of Coptidis Preparation in Combination with Lovastatin in High-Fat Diet-Induced Hyperlipidemic Rats.

Lovastatin is a standard therapy for dyslipidemia. Alternatively, some ethnomedicines, such as Coptidis preparation, have been used for the treatment of dyslipidemia. Statins and complementary and alternative medicines may possess individual mechanisms of action against dyslipidemia. We hypothesize that the combination of Coptidis preparation and lovastatin may have synergistic effects for the treatment of dyslipidemia. To investigate this hypothesis, we developed a validated ultra-high-performance liquid chromatography-tandem mass spectrometry method to monitor lovastatin and its metabolites for pharmacokinetic studies in rats. This study was divided into four groups: lovastatin (10 mg/kg, p.o.) alone and lovastatin (10 mg/kg, p.o.) + Coptidis preparation (0.3, 1, or 3 g/kg, p.o.) for five consecutive days. In pharmacodynamic studies, a high-fat diet (HFD) was used to induce dyslipidemia in experimental rat models. The HFD rats were divided into four groups: treatment with HFD, HFD + lovastatin (100 mg/kg, p.o.), HFD + Coptidis preparation (1 g/kg, p.o.), and HFD + lovastatin (50 mg/kg, p.o.) + Coptidis preparation (1 g/kg, p.o.) for 28 consecutive days. The pharmacokinetic results demonstrated that Coptidis preparation significantly augmented the conversion of lovastatin into its main metabolite lovastatin acid in vivo. The pharmacodynamic results revealed that the Coptidis preparation and half-dose lovastatin group reduced the body weight, liver weight, and visceral fat in HFD rats. These findings provide constructive preclinical pharmacokinetic and pharmacodynamic applications of Coptidis preparation on the benefit of hyperlipidemia.

Discovery of an orally active VHL-recruiting PROTAC that achieves robust HMGCR degradation and potent hypolipidemic activity in vivo

HMG-CoA reductase (HMGCR) protein is usually upregulated after statin (HMGCR inhibitor) treatment, which inevitably diminishes its therapeutic efficacy, provoking the need for higher doses associated with adverse effects. The proteolysis targeting chimera (PROTAC) technology has recently emerged as a powerful approach for inducing protein degradation. Nonetheless, due to their bifunctional nature, developing orally bioavailable PROTACs remains a great challenge. Herein, we identified a powerful HMGCR-targeted PROTAC (21c) comprising a VHL ligand conjugated to lovastatin acid that potently degrades HMGCR in Insig-silenced HepG2 cells (DC50 = 120 nmol/L) and forms a stable ternary complex, as predicated by a holistic modeling protocol. Most importantly, oral administration of the corresponding lactone 21b reveled favorable plasma exposures referring to both the parent 21b and the conversed acid 21c. Further in vivo studies of 21b demonstrated robust HMGCR degradation and potent cholesterol reduction in mice with diet-induced hypercholesterolemia, highlighting a promising strategy for treating hyperlipidemia and associated diseases.

Exploring the extremes: applying high concentration of yeast extract leads to drastic morphological changes and elimination of (+)-geodin and asterric acid production in Aspergillus terreus submerged cultures

ObjectiveEvaluation of morphology and secondary metabolites production in Aspergillus terreus ATCC 20542 cultures over a wide range of lactose and yeast extract concentrations from 0.2 up to an extremely high level of 200 g l−l.ResultsThe morphological differences of mycelial objects were quantified with the use of morphological parameters calculated by applying the tools of digital image analysis. At 200 g l−l of yeast extract clumps and loose hyphae were recorded instead of pellets commonly observed in submerged cultures of A. terreus. Under these conditions the biosynthesis of (+)-geodin and asterric acid was totally blocked, lovastatin formation was found to be at a relatively low level and biomass production turned out to be greater than in the remaining variants, where the pelleted growth was observed. At 200 g l−l of lactose the production of lovastatin, (+)-geodin and asterric acid was visibly stimulated compared to the media containing 0.2, 2 and 20 g l−l of the sugar substrate, but at the same time no traces of butyrolactone I could be detected in the broth. Lactose at the extremely high concentration of 200 g l−l did not induce the drastic morphological changes observed in the case of 200 g l-1 of yeast extract. It was proved that at the C/N values as low as 4 and as high as 374 A. terreus not only continued to display growth but also exhibited the production of secondary metabolites. The use of cultivation media representing the equivalent C/N ratios led to different metabolic and morphological outcomes depending on the concentration of lactose and yeast extract that contributed to the given C/N value.ConclusionThe extremely high concentration of yeast extract leads to marked morphological changes of A. terreus and the elimination of (+)-geodin and asterric production, while applying the excess of lactose is stimulatory in terms of lovastatin production.

The characteristics and mechanism of co-administration of lovastatin solid dispersion with kaempferol to increase oral bioavailability

Lovastatin shows low bioavailability (lower than 5%) after oral administration because of the poor aqueous solubility and widely metabolized by CYP3A4.Lovastatin solid dispersion was designed to enhance the dissolution. The in vitro intestinal absorption study indicated an increase in the apparent permeability of different intestinal segments compared with crude lovastatin. In the range of 12.5–50 μg/ml, the absorption of both lovastatin and lovastatin solid dispersion were found to be a passive process in rat’s jejunum and ileum, but not endocytosis process. CYP3A4 inhibitor (ketoconazole) significantly increased the intestinal absorption of lovastatin and lovastatin solid dispersion. However, P-glycoprotein efflux inhibitor (verapamil) had little effect on them.The absolute bioavailability of lovastatin and lovastatin acid after oral administration of lovastatin solid dispersion were increased by about 2.01-fold and 1.40-fold than that of lovastatin suspension. The oral bioavailability of lovastatin and lovastatin acid after oral administration of lovastatin solid dispersion with 10 mg/kg kaempferol (CYP3A4 inhibitor) were increased about 3.79-fold and 2.51-fold than that of lovastatin suspension, and the absolute bioavailability of lovastatin was up to 33.0%.As a result, co-administration of lovastatin solid dispersion with kaempferol could be a promising delivery system to improve the oral bioavailability of lovastatin.

Analysis of a Skeletal Muscle Injury and Drug Interactions in Lovastatin- and Fenofibrate-Coadministered Dogs.

Because dogs are widely used in drug development as nonrodent experimental animals, using a dog model for drug-induced adverse reactions is considered to be relevant for an evaluation and investigation of a mechanism and a biomarker of clinical drug-induced adverse reactions. Skeletal muscle injury occurs by various drugs, including statins and fibrates, during drug development. However, there is almost no report of a dog model for drug-induced skeletal muscle injury. In the present study, we induced skeletal muscle injury in dogs by oral coadministration of lovastatin (LV) and fenofibrate (FF) for 4 weeks. Increases in plasma levels of creatine phosphokinase, myoglobin, miR-1, and miR-133a and degeneration/necrosis of myofibers in skeletal muscles but not in the heart were observed in LV- and FF-coadministered dogs. Plasma levels of lovastatin lactone and lovastatin acid were higher in LV- and FF-coadministered dogs than LV-administered dogs. Taken together, FF coadministration is considered to affect LV metabolism and result in skeletal muscle injury.

Isoflavones enhance pharmacokinetic exposure of active lovastatin acid via the upregulation of carboxylesterase in high-fat diet mice after oral administration of Xuezhikang capsules.

Xuezhikang capsule (XZK) is a traditional Chinese medicine that contains lovastatin (Lv) for hyperlipidemia treatment, although it has fewer side effects than Lv. However, the pharmacokinetic mechanisms contributing to its distinct efficacy and low side effects are unclear. Mice were fed a high-fat diet (HFD) for 6 weeks to induce hyperlipidemia. We first conducted the pharmacokinetic studies in HFD mice following oral administration of Lv (10 mg/kg, i.g.) and found that HFD remarkably decreased the active form of Lv (the lovastatin acid, LvA) exposure in the circulation system, especially in the targeting organ liver, with a declined conversion from Lv to LvA, whereas the Lv (responsible for myotoxicity) exposure in muscle markedly increased. Then we compared the pharmacokinetic profiles of Lv in HFD mice after the oral administration of XZK (1200 mg/kg, i.g.) or an equivalent dose of Lv (10 mg/kg, i.g.). A higher exposure of LvA and lower exposure of Lv were observed after XZK administration, suggesting a pharmacokinetic interaction of some ingredients in XZK. Further studies revealed that HFD promoted the inflammation and inhibited carboxylesterase (CES) activities in the intestine and the liver, thus contributing to the lower transformation of Lv into LvA. In contrast, XZK inhibited the inflammation and upregulated CES in the intestine and the liver. Finally, we evaluated the effects of monacolins and phytosterols, the fractional extracts of isoflavones, on inflammatory LS174T or HepG2 cells, which showed that isoflavones inhibited inflammation, upregulated CES, and markedly enhanced the conversion of Lv into LvA. For the first time, we provide evidence that isoflavones and Lv in XZK act in concert to enhance the efficacy and reduce the side effects of Lv.

Quantitation of lovastatin and its hydroxy acid in human plasma by high-performance liquid chromatography-tandem mass spectrometry

An HPLC-MS/MS method was described for the quantitation of lovastatin and its main hydroxy acid metabolite lovastatin acid in human plasma. Lovastatin was detected in the positive ion mode, while Lovastatin acid was detected in the negative mode in a single injection, with simvastatin and simvastatin acid as internal standard, respectively. Plasma sample was treated by one-step liquid-liquid extraction with dichloromethane-diethyl ether (2:3 v/v). LC separation was performed within 4 min on a Zorbax Eclipse XDB-C8 column (5 μm, 4.6 × 150 mm I.D.) using 90% methanol-10% – 10 mmol/l ammonium acetate solution which contains 0.02% formic acid as mobile phase. Linear calibration curves were obtained in the concentration range 0.05–30.0 ng/ml. The intra- and inter-day precision values were below 15% and the accuracy was within ±15% at three quality control levels for both lovastatin and lovastatin acid. It was successfully applied to a pharmacokinetic study in 12 healthy volunteers after a single oral dose of 40 mg per subject.

Effects of a Series of Acidic Drugs on L-Lactic Acid Transport by the Monocarboxylate Transporters MCT1 and MCT4.

Drug-induced myopathy is a serious side effect that often requires removal of a medication from a drug regimen. For most drugs, the underlying mechanism of drug-induced myopathy remains unclear. Monocarboxylate transporters (MCTs) mediate L-lactic acid transport, and inhibition of MCTs may potentially lead to perturbation of L-lactic acid accumulation and muscular disorders. Therefore, we hypothesized that L-lactic acid transport may be involved in the development of drug-induced myopathy. The aim of this study was to assess the inhibitory potential of 24 acidic drugs on L-lactic acid transport using breast cancer cell lines Hs578T and MDA-MB-231, which selectively express MCT1 and MCT4, respectively. The influx transport of L-lactic acid was minimally inhibited by all drugs tested. The efflux transport was next examined: loratadine (IC50: 10 and 61 µM) and atorvastatin (IC50: 78 and 41 µM) demonstrated the greatest potency for inhibition of L-lactic acid efflux by MCT1 and MCT4, respectively. Acidic drugs including fluvastatin, cerivastatin, simvastatin acid, lovastatin acid, irbesartan and losartan exhibited weak inhibitory potency on L-lactic acid efflux. Our results suggest that some acidic drugs, such as loratadine and atorvastatin, can inhibit the efflux transport of L-lactic acid. This inhibition may cause an accumulation of intracellular L-lactic acid leading to acidification and muscular disorders.

Development and Validation of LC-MS/MS Method for the Estimation of Lovastatin and its Metabolite (β-Hydroxy Acid) in Pharmaceutical Dosage Form

The objective of this study was to validate a simple, specific, accurate and precise Liquid - Liquid extraction high performance liquid chromatographic method with Tandem Mass Spectrometry-Thermo Scientific TSQ Quantum Ultra method for the determination of Lovastatin and Lovastatin acid in human plasma using Atorvastatin as Internal Standard (IS). The precision and accuracy data have to fulfill the requirements for quantification of the analytes in biological matrices to generate data for bioequivalence, bioavailability investigations. A Luna C18, 5µmcolumn having 4.6 x 150 mm internal diameter in isocratic elution mode with flow rate1.0 mL/min of mobile phase containing and Methanol, 5mM ammonium formate in 0.1% formic acid (80:20v/v) were used. The chromatographic separation was achieved by using elution solution consisting of Methanol and 5mM ammonium formate in 0.1% formic acid (80:20%v/v), diluent solution of methanol and water (50:50%,v/v) were monitored on a triple quadrupole massspectrometer, operating in the multiple reaction monitoring (MRM) mode. The method was validated for both Lovastatin and Lovastatin acid over the concentration range of 0.05- 5.00 ng/mL using 300 µL plasma samples. Limit of quantification was found 0.05 ng/mL. The retention time for Lovastatin acid and Lovastatin min 2.84 and 3.45 respectively and Internal Standard were 2.06 min and overall chromatography run time was 5.50 minutes. The mean recovery of Lovastatin (71.00%) and Lovastatin acid (81.20) and IS (79.84%) from spiked plasma samples was consistent and reproducible. The method was validated for linearity, accuracy, precision, specificity, limit of quantification and robustness. The intra- and inter-day precision and accuracy values were found to be within the assay variability limits as per the FDA guidelines1. The developed assay method was applied to a clinical pharmacokinetic study in human volunteers.

Effect of Polymorphisms in CYP3A4, PPARA, NR1I2, NFKB1, ABCG2 and SLCO1B1 on the Pharmacokinetics of Lovastatin in Healthy Chinese Volunteers

This study examined whether gene polymorphisms (CYP3A4, ABCG2, SLCO1B1, NR1I2, PPARA and NFKB1) influenced the pharmacokinetics of lovastatin in Chinese healthy subjects. Plasma concentrations of lovastatin and lovastatin acid were quantified using LC/MS/MS. PPARA c.208+3819 G allele carriers had approximately twofold higher AUC0-∞ and Cmax of lovastatin than wild-type (PPARA c.208+3819 AA) subjects. After adjustment for the PPARA variants, subjects with the SLCO1B1 521TT genotype had approximately 50% lower AUC0-∞ of lovastatin acid than those with 521TC/CC genotypes, while the AUC0-∞ of lovastatin lactone in NFKB1-94 DD wild-type carriers was twofold higher than in mutant homozygotes carriers. Gene polymorphisms of PPARA, SLCO1B1 and NFKB1 affected the pharmacokinetics of lovastatin.

Simultaneous determination of lovastatin and its metabolite lovastatin acid in rat plasma using UPLC–MS/MS with positive/negative ion-switching electrospray ionization: Application to a pharmacokinetic study of lovastatin nanosuspension

Lovastatin (LOV) is an antihyperlipidemic agent which exhibits low bioavailability due to its poor solubility. Therefore, a nanosuspension (NS) was developed as an efficient strategy to improve its oral bioavailability. To evaluate the pharmacokinetics of LOV-NS, a novel, sensitive, and rapid UPLC-MS/MS method was developed and validated for the simultaneous determination of LOV and its metabolite lovastatin acid (LOVA) in rat plasma. Simvastatin (IS) was chosen as the internal standard, and a liquid-liquid extraction method was used to isolate LOV and LOVA from biological matrices. The analytes were analyzed on an Acquity UPLC BEH C18 column, and a gradient program was applied at a flow rate of 0.2mL/min. Then, a tandem quadrupole mass spectrometer coupled with a positive/negative ion-switching electrospray ionization interface was employed to detect the analytes. Quantitation of the analytes was performed in the multiple reaction monitoring mode to monitor the transitions of m/z 427.1→325.0 for LOV and m/z 441.1→325.0 for IS in the positive ion mode and m/z 421.0→101.0 for LOVA in the negative ion mode, respectively. The method was validated over the concentration range 0.25-500ng/mL (r(2)≥0.99) for both LOV and LOVA. The intra-day and inter-day precision (RSD%) of LOV and LOVA were less than 12.87% and the accuracy (RE%) was less than 5.22%. The average extraction recoveries were 90.1% and 91.9% for LOV and LOVA, and the matrix effects were found to be between 85% and 115%. The stability study showed that both analytes were stable during the experiment. Finally, this method has been successfully applied to a pharmacokinetic study in rats following a single oral dose of 10mg/kg LOV-NS.

SLCO1B1 polymorphism markedly affects the pharmacokinetics of lovastatin acid.

Organic anion transporting polypeptide 1B1 (OATP1B1, encoded by SLCO1B1 gene) is a hepatic uptake transporter, and its genetic variability is associated with pharmacokinetics and muscle toxicity risk of simvastatin. We examined the possible effects of variations in the SLCO1B1 gene on the pharmacokinetics of lovastatin in a prospective genotype panel study. Seven healthy volunteers with the SLCO1B1*1B/*1B genotype, five with the SLCO1B1*5/*15 or *15/*15 genotype, and 15 with the SLCO1B1*1A/*1A genotype (controls) were recruited. Each study participant ingested a single 40-mg dose of lovastatin. Plasma concentrations of lovastatin (inactive lactone) and its active metabolite lovastatin acid were measured up to 24 h. In the SLCO1B1*5/*15 or *15/*15 genotype group, the geometric mean Cmax and AUC0-24 of lovastatin acid were 340 and 286% of the corresponding values in the SLCO1B1*1A/*1A (reference) genotype group (P<0.005). In contrast, the AUC0-24 of lovastatin acid in the SLCO1B1*1B/*1B genotype group was only 68% of that in the reference genotype group (P=0.03). No statistically significant association was observed between the SLCO1B1 genotype and the pharmacokinetics of lovastatin lactone. SLCO1B1*5/*15 and *15/*15 genotypes markedly increase the exposure to active lovastatin acid, but have no significant effect on lovastatin lactone, similar to their effects on simvastatin and simvastatin acid. Accordingly, it is probable that the risk of muscle toxicity during lovastatin treatment is increased in individuals carrying the SLCO1B1*5 or *15 allele. The SLCO1B1*1B/*1B genotype is associated with reduced lovastatin acid concentrations, consistent with enhanced hepatic uptake.

Optimization, validation and application of an assay for the activity of HMG-CoA reductase in vitro by LC–MS/MS

A stable HMG-CoA reductase (HMGR) reaction in vitro was developed by a sensitive, selective and precise liquid chromatography–tandem mass spectrometry (LC–MS/MS) method. The optimized enzyme reaction condition contained 1.5μg of HMGR, 20nM of NADPH with 50min of reaction time. The method was validated by several intra- and inter-day assays. The production transitions of m/z 147.0/59.1 and m/z 154.0/59.1 were used to detect and quantify mevalonolactone (MVAL) and MVAL-D7, respectively. The accuracy and precision of the method were evaluated over the concentration range of 0.005–1.000μg/mL for MVAL and 0.010–0.500μg/mL for lovastatin acid in three validation batch runs. The lower limit of quantitation was found to be 0.005μg/mL for MVAL and 0.010μg/mL for lovastatin acid. Intra-day and inter-day precision ranged from 0.95% to 2.39% and 2.26% to 3.38% for MVAL, 1.46% to 3.89% and 0.57% to 5.10% for lovastatin acid, respectively. The results showed that the active ingredients in Xuezhikang capsules were 12.2 and 14.5mg/g, respectively. This assay method could be successfully applied to the quality control study of Xuezhikang capsule for the first time.

Application of the extended clearance concept classification system (ECCCS) to predict the victim drug-drug interaction potential of statins.

During drug development, it is an important safety factor to identify the potential of new molecular entities to become a victim of drug-drug interactions (DDIs). In preclinical development, however, anticipation of clinical DDIs remains challenging due to the lack of in vivo human pharmacokinetic data. We applied a recently developed in vitro-in vivo extrapolation method, including hepatic metabolism and transport processes, herein referred to as the Extended Clearance Concept Classification System (ECCCS). The human hepatic clearances and the victim DDI potentials were predicted for atorvastatin, cerivastatin, fluvastatin, lovastatin acid, pitavastatin, pravastatin, rosuvastatin, and simvastatin acid. Hepatic statin clearances were well-predicted by the ECCCS with six out of eight clearances projected within a two-fold deviation to reported values. In addition, worst-case DDI predictions were projected for each statin. Based on the ECCCS class assignment (4 classes), the mechanistic interplay of metabolic and transport processes, resulting in different DDI risks, was well-reflected by our model. Furthermore, predictions of clinically observed statins DDIs in combination with relevant perpetrator drugs showed good quantitative correlations with clinical observations. The ECCCS represents a powerful tool to anticipate the DDI potential of victim drugs based on in vitro drug metabolism and transport data.

Rod shaped nanocrystals exhibit superior in vitro dissolution and in vivo bioavailability over spherical like nanocrystals: A case study of lovastatin

The objective of this study was to compare the in vitro and in vivo performance of rod shaped and spherical like nanocrystals for oral administration. Lovastatin (LOV) was chosen as the model drug and LOV rod shaped nanocrystals (LOV-RNs) and spherical like nanocrystals (LOV-SNs) were prepared by sonoprecipitation and bead milling, respectively. The dry powders obtained following freeze-drying were characterized by hydrodynamic diameter, polydispersity index, zeta potential, transmission electron microscope, scanning electron microscope, atomic force microscope, differential scanning calorimetry, Fourier transform infrared spectroscopy, and in vitro dissolution test. The pharmacokinetic study was performed in beagle dogs. The results obtained showed that LOV-RNs and LOV-SNs had similar hydrodynamic diameters (500.6±21.0nm versus 503.2±20.4nm), and the same crystalline state. The dissolution test showed that LOV-RNs had a higher dissolution rate than LOV-SNs. The AUC(0–24h) values of LOV-RNs and LOV-SNs were higher than Junning® for both LOV (p<0.05 for LOV-RNs, and p>0.05 for LOV-SNs) and lovastatin acid (p>0.05). More importantly, the oral bioavailability of LOV-RNs was higher than LOV-SNs (p>0.05). The findings of this study show that the crystal shape has a significant effect on oral bioavailability.

Liquid chromatography-tandem mass spectrometry assay for the simultaneous quantification of simvastatin, lovastatin, atorvastatin, and their major metabolites in human plasma.

Millions of individuals are treated with a variety of statins that are metabolized to a variety of active metabolites. A single assay capable of simultaneously quantifying commonly used statins and their major metabolites has not been previously reported. Herein we describe the development and validation of a novel and robust liquid chromatography-tandem mass spectrometry assay for simultaneously quantifying simvastatin, lovastatin, atorvastatin, and their metabolites, simvastatin acid, lovastatin acid, para-hydroxy atorvastatin, and ortho-hydroxy atorvastatin in human plasma. Plasma samples were processed with a simple protein precipitation technique using acetonitrile, followed by chromatographic separation using an Agilent Zorbax Extend C18 column. A 12.0min linear gradient elution was used at a flow rate of 400μL/min with a mobile phase of water and methanol, both modified with 2mM ammonium formate and 0.2% formic acid. The analytes and internal standard, hesperetin, were detected using the selected reaction monitoring mode on a TSQ Quantum Discovery mass spectrometer with positive electrospray ionization. The assay exhibited a linear range of 1-1000nM for simvastatin acid and lovastatin acid, and a linear range of 0.1-100nM for the other analytes in human plasma. The accuracy and the within- and between-day precisions of the assay were within acceptable ranges, and the method was successfully utilized to quantify the statins and their metabolites in human plasma samples collected from an ongoing pharmacokinetic study.

A Simple Protein Precipitation-based Simultaneous Quantification of Lovastatin and Its Active Metabolite Lovastatin Acid in Human Plasma by Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry using Polarity Switching.

Lovastatin is an anti-cholesterol lactone drug indicated for the treatment of hyperlipidemia and to reduce the risk of coronary heart disease. It is converted to the β-hydroxy acid form (lovastatin acid) in vivo, which is the major pharmacologically active metabolite. Here, we describe the development and validation of an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS)-based method utilizing polarity switching for the simultaneous quantification of lovastatin and lovastatin acid in human plasma. Simple protein precipitation extraction and direct injection of the extracted samples without drying/reconstitution showed good recoveries of both analytes (~70%). The developed method exhibited satisfactory intra-day and inter-day accuracy and precision. The interconversion between lovastatin and lovastatin acid during sample preparation and storage was minimal (< 1.9%). The lower limits of quantification were 0.5 and 0.2 nM (or 0.2 and 0.084 ng/mL) for lovastatin and lovastatin acid, respectively, using only 50 μL of plasma during extraction. The validated method was successfully applied to analyze plasma samples obtained from a healthy human subject who enrolled in a clinical drug interaction study involving lovastatin.

Synthesis of a diastereomeric mixture of deuterium-labeled lovastatin and its acid ammonium salt

In this communication, a facile synthesis for (2S/2R)-[2H3]lovastatin and (2S/2R)-[2H3]lovastatin acid ammonium salt was described. The stable isotope-labeled (2S/2R)-lovastatin and its acid ammonium salt were prepared from butyric acid via several reaction steps with 11.1 and 6.3 % overall yield, respectively.

Simultaneous determination of statins in dietary supplements by ultra-performance liquid chromatography

A method for the determination of 12 statins [atorvastatin (ATOR), cerivastatin (CERI), fluvastatin (FLU), lovastatin (LO), lovastatin acid (LOA), mevastatin (ME), mevastatin acid (MEA), pitavastatin (PITA), pravastatin (PRA), rosuvastatin (ROSU), simvastatin (SIM), and simvastatin acid (SIMA)] in dietary supplements by ultra-performance liquid chromatography (UPLC) has been developed. Statins were ultrasonically extracted with 50% (v/v) methanol. Clean-up was performed using an Oasis MAX mini-cartridge column with methanol and methanol containing 0.2% (v/v) phosphoric acid as an eluting solvent. UPLC separation was performed on an ACQUITY UPLC BEH C18 column (2.1 mm i.d. × 150 mm, 1.7 μm) with 0.2% (v/v) phosphoric acid aqueous solution-acetonitrile gradient. The method was validated for dietary supplements spiked with the 12 statins at the quantitation limits and 10 times the quantitation limits, and the recoveries of statins were between 89.2% and 100.9%. Relative standard deviation values of repeatability and intermediate precision were not more than 7%. The analytical method was applied to 24 commercial dietary supplements. LO and LOA were found at maximum concentrations of 4.85 mg/packet and 1.28 mg/capsule, respectively. Other statins were not detected. When a dietary supplement was consumed according to the directions on the package, the daily intake of LO was 6.74 mg. This could be dangerous to consumers because it exceeds one half of the lowest recommended daily dose of LO (10 mg).