Exercise-Induced Excessive Blood Pressure Elevation Is Associated with Cardiac Dysfunction in Male Patients with Essential Hypertension.

Objective: Cardiopulmonary exercise testing (CPET) has been used to explore the blood pressure response and potential cardiovascular system structure and dysfunction in male patients with essential hypertension during exercise, to provide a scientific basis for safe and effective exercise rehabilitation and improvement of prognosis. Methods: A total of 100 male patients with essential hypertension (aged 18-60) who were admitted to the outpatient department of the Center for Diagnosis and Treatment of Cardiovascular Diseases of Jilin University from September 2018 to January 2021 were enrolled in this study. The patients had normal cardiac structure in resting state without clinical manifestations of heart failure or systematic regularization of treatment at the time of admission. Symptom-restricted CPET was performed and blood pressure was measured during and after exercise. According to Framingham criteria, male systolic blood pressure (SBP) ≥210 mmHg during exercise was defined as exercise hypertension (EH), and the subjects were divided into EH group (n = 47) and non-EH group (n = 53). Based on whether the oxygen pulse (VO2/HR) plateau appeared immediately after anaerobic threshold (AT), the EH group was further divided into the VO2/HR plateau immediately after AT (EH-ATP) group (n = 19) and EH-non-ATP group (n = 28). The basic clinical data and related parameters, key CPET indicators, were compared between groups. Result: Body mass index (BMI) visceral fat, resting SBP, and SBP variability in EH group were significantly higher than those in non-EH group. Moreover, VO2/HR at AT and the ratio of VO2/HR plateau appearing immediately after AT in EH group were significantly higher than those in the non-EH group. The resting SBP, 15-minute SBP variability, and the presence of VO2/HR plateau were independent risk factors for EH. In addition, work rate (WR) at AT but also WR, oxygen consumption per minute (VO2), VO2/kg, and VO2/HR at peak were significantly lower in the EH-ATP group compared to the EH-non-ATP group. Peak diastolic blood pressure (DBP) increment and decreased △VO2/△WR for AT to peak were independent risk factors for VO2/HR plateau appearing immediately after AT in EH patients. Conclusion: EH patients have impaired autonomic nervous function and are prone to exercise-induced cardiac dysfunction. EH patients with exercise-induced cardiac dysfunction have reduced peak cardiac output and exercise tolerance and impaired vascular diastolic function. CPET examination should be performed on EH patients and EH patients with exercise-induced cardiac dysfunction to develop precise drug therapy and effective individual exercise prescription, to avoid arteriosclerosis and exercise-induced cardiac damage. The retrospective study protocol was approved by medical ethics committee of the First Hospital of Jilin University (AF-IRB-032-06 No. 2021-015). The study was registered with the Chinese Clinical Trials Register, registration number: ChiCTR2100053140.

Pharmacokinetics of Subcutaneous Dupilumab Injection With an Autoinjector Device or Prefilled Syringe.

Dupilumab, a human monoclonal antibody against interleukin-4 receptor alpha, has demonstrated efficacy and an acceptable safety profile in adult and pediatric patients with moderate-to-severe atopic dermatitis (AD) and other type 2 inflammatory diseases. Dupilumab is available in 200- and 300-mg strengths as a prefilled syringe with a needle shield (PFS-S), and more recently as an autoinjector (AI) device. This study was designed to assess the pharmacokinetic (PK) comparability of a single subcutaneous (SC) dose of dupilumab 200 mg, delivered by 2 different devices, AI (test) versus PFS-S (reference). A total of 130 healthy male and female participants were enrolled in this phase 1 parallel design study, with 128 evaluable for PK. Following dupilumab 200-mg SC injection, dupilumab exposure in serum was similar for both AI and PFS-S. The geometric mean ratios of PK parameters with 90% confidence intervals were 1.08 (0.97-1.21) for maximum serum concentration (Cmax ) and 1.11 (0.96-1.28) for area under the serum concentration-time curve until the last quantifiable concentration (AUClast ). Dupilumab administration by both devices was well tolerated, and there were no serious adverse events, or severe treatment-emergent adverse events experienced during the study. Overall, exposure to dupilumab 200 mg was comparable when administered via the AI or PFS-S devices in healthy male and female study participants.

A Rare Case of Adult Aortopulmonary Window Combined with Anomalous Origin of the Right Pulmonary Artery from the Aorta Leading to Eisenmenger Syndrome.

Aortopulmonary window is a rare congenital heart disease that can increase pulmonary vascular resistance, exacerbate left-to-right shunt and lead to heart failure and respiratory tract infections. Most patients die during childhood. We report a 53-year-old male patient with a large aortopulmonary window combined with anomalous origin of the right pulmonary artery from the aorta, with Eisenmenger syndrome and without surgery.

Physiologically-Based Pharmacokinetic Modeling in Renal and Hepatic Impairment Populations: A Pharmaceutical Industry Perspective.

The predictive performance of physiologically-based pharmacokinetics (PBPK) models for pharmacokinetics (PK) in renal impairment (RI) and hepatic impairment (HI) populations was evaluated using clinical data from 29 compounds with 106 organ impairment study arms were collected from 19 member companies of the International Consortium for Innovation and Quality in Pharmaceutical Development. Fifty RI and 56 HI study arms with varying degrees of organ insufficiency along with control populations were evaluated. For RI, the area under the curve (AUC) ratios of RI to healthy control were predicted within twofold of the observed ratios for > 90% (N = 47/50 arms). For HI, > 70% (N = 43/56 arms) of the hepatically impaired to healthy control AUC ratios were predicted within twofold. Inaccuracies, typically overestimation of AUC ratios, occurred more in moderate and severe HI. PBPK predictions can help determine the need and timing of organ impairment study. It may be suitable for predicting the impact of RI on PK of drugs predominantly cleared by metabolism with varying contribution of renal clearance. PBPK modeling may be used to support mild impairment study waivers or clinical study design.

Food Effect Projections via Physiologically Based Pharmacokinetic Modeling: Predictive Case Studies.

Food can alter the absorption of orally administered drugs. Biopharmaceutics physiologically based pharmacokinetic (PBPK) modeling offers the possibility to simulate a compound's pharmacokinetics under fasted or fed states. To advance the utility of PBPK modeling, with a view to regulatory impact, we have pooled our experience across 4 pharmaceutical companies to propose a general multistep PBPK workflow leveraging pre-existing clinical data for immediate-release formulations of Biopharmaceutics Classification System I and II compounds. With this strategy, we wish to promote pragmatic PBPK approaches for compounds where absorption is well understood, that is, compounds with moderate-to-high permeability that are not substrates for uptake transporters. Five case studies demonstrate how food effect can be well predicted using appropriately established and validated models. The case studies integrate solubility and dissolution data for initial model development and apply a "middle-out" validation with clinical data in one prandial state. Then, whenever possible, a validation against both fasted and fed state data is recommended before application of the models prospectively for to-be-marketed formulations. Thus, when combined with limited clinical data, PBPK models could be used to simulate outcomes for new doses, formulations, or active pharmaceutical ingredient forms, in lieu of a clinical food-effect study.

Integration of Precipitation Kinetics From an In Vitro, Multicompartment Transfer System and Mechanistic Oral Absorption Modeling for Pharmacokinetic Prediction of Weakly Basic Drugs.

Solubility, dissolution, and precipitation in the gastrointestinal tract can be critical for the oral bioavailability of weakly basic drugs. To understand the dissolution and precipitation during the transfer out of the stomach into the intestine, a multicompartment transfer system was developed by modifying a conventional dissolution system. This transfer system included gastric, intestinal, sink and supersaturation, and reservoir compartments. Simulated gastric fluid and fasted state simulated intestinal fluid were used in the gastric and intestinal compartment, respectively, to mimic fasted condition. The new transfer system was evaluated based on 2 model weak bases, dipyridamole and ketoconazole. Traditional 2-stage dissolution using 250 mL of simulated gastric fluid media, followed by 250 mL of fasted state simulated intestinal fluid, was used as a reference methodology to compare dissolution and precipitation results. An in silico model was built using R software suite to simulate the in vitro time-dependent dissolution and precipitation process when formulations were tested using the transfer system. The precipitation rate estimated from the in vitro data was then used as the input for absorption and pharmacokinetic predictions using GastroPlus. The resultant simulated plasma concentration profiles were generally in good agreement with the observed clinical data, supporting the translatability of the transfer system in vitro precipitation kinetics to in vivo.

A canine biorelevant dissolution method for predicting in vivo performance of orally administered sustained release matrix tablets.

Preclinical species are a crucial component of drug development, but critical differences in physiology and anatomy need to be taken into account when attempting to extrapolate to humans or between species. The same is true when trying to develop oral formulations for preclinical species, especially unconventional formulations, such as sustained release tablets. During the evaluation of such specialized dosage forms, dissolution can be a critical in vitro tool used to rank-order formulations and ultimately choose the desired release rate. Here, the development of a canine biorelevant dissolution method for the prediction of the in vivo performance of sustained release matrix tablets in beagle dogs is described. The method accounts for differences in physiology between humans and dogs such as gastrointestinal fluid composition, gastric emptying forces, and gastric residence time. The most critical dissolution method parameters were found to be the paddle speed used to simulate the gastric emptying forces as well as the time spent in simulated gastric fluid. The resulting differences in method conditions are further explored through in silico models of the hydrodynamic forces applied to a dosage form. Two case studies are reported showing that the method was able to obtain excellent in vitro-in vivo relationships (slopes ranging from 1.08-1.01) which are significantly (p < 0.01-0.05) improved compared to human biorelevant dissolution used to predict in vivo performance in humans (slopes ∼1.5-1.75). The quality of the method's predictive ability allows for it to help drive the development of matrix sustained release formulations intended for preclinical studies.

Comparison of Deconvolution-Based and Absorption Modeling IVIVC for Extended Release Formulations of a BCS III Drug Development Candidate.

In vitro-in vivo correlations (IVIVC) are predictive mathematical models describing the relationship between dissolution and plasma concentration for a given drug compound. The traditional deconvolution/convolution-based approach is the most common methodology to establish a level A IVIVC that provides point to point relationship between the in vitro dissolution and the in vivo input rate. The increasing application of absorption physiologically based pharmacokinetic model (PBPK) has provided an alternative IVIVC approach. The current work established and compared two IVIVC models, via the traditional deconvolution/convolution method and via absorption PBPK modeling, for two types of modified release (MR) formulations (matrix and multi-particulate tablets) of MK-0941, a BCS III drug development candidate. Three batches with distinct release rates were studied for each formulation technology. A two-stage linear regression model was used for the deconvolution/convolution approach while optimization of the absorption scaling factors (a model parameter that relates permeability and input rate) in Gastroplus(TM) Advanced Compartmental Absorption and Transit model was used for the absorption PBPK approach. For both types of IVIVC models established, and for either the matrix or the multiparticulate formulations, the average absolute prediction errors for AUC and C max were below 10% and 15%, respectively. Both the traditional deconvolution/convolution-based and the absorption/PBPK-based level A IVIVC model adequately described the compound pharmacokinetics to guide future formulation development. This case study highlights the potential utility of absorption PBPK model to complement the traditional IVIVC approaches for MR products.

Development of a Novel Oral Cavity Compartmental Absorption and Transit Model for Sublingual Administration: Illustration with Zolpidem.

Intraoral (IO) delivery is an alternative administration route to deliver a drug substance via the mouth that provides several advantages over conventional oral dosage forms. The purpose of this work was to develop and evaluate a novel, physiologically based oral cavity model for projection and mechanistic analysis of the clinical pharmacokinetics of intraoral formulations. The GastroPlus™ Oral Cavity Compartmental Absorption and Transit (OCCAT™) model was used to simulate the plasma concentration versus time profiles and the fraction and rate of intraoral drug transit/absorption for Intermezzo® sublingual tablets (zolpidem tartrate). The model was evaluated by the goodness-of-fit between simulated and observed concentrations and the deviation of key PK parameters (e.g., C max, T max, and AUC). In addition, a sensitivity analysis was conducted to demonstrate the interplay and impact of key modeling parameters on the fraction absorbed via oral mucosa (F a_IO). The OCCAT™ model captured the observed pharmacokinetics for Intermezzo® sublingual tablets (R (2) > 0.9). The predicted deviations (%) for C max, AUC0-inf, AUC0-20 min, and T max were 5.7, 28.0, 11.8, and 28.6%, respectively, indicating good prediction accuracy. The model also estimated ~18% of total drug was absorbed via the IO route. Furthermore, the sensitivity analysis indicated that the F a_IO was not only associated with drug diffusivity and unbound fraction in epithelium tissue (f ut) but also depended on the physicochemical properties of compounds for IO delivery (e.g., solubility and logD pH = 7.4). The novel physiologically based IO absorption OCCAT™ model showed satisfactory performance and will be helpful to guide development of future intraoral formulations.

Physiologically based pharmacokinetic modeling for assessing the clinical drug-drug interaction of alisporivir.

Alisporivir is a novel cyclophilin-binding molecule with potent anti-hepatitis C virus (HCV) activity. In vitro data from human liver microsomes suggest that alisporivir is a substrate and a time-dependent inhibitor (TDI) of CYP3A4. The aim of the current work was to develop a novel physiologically based pharmacokinetic (PBPK) model to quantitatively assess the magnitude of CYP3A4 mediated drug-drug interactions with alisporivir as the substrate or victim drug. Towards that, a Simcyp PBPK model was developed by integrating in vitro data with in vivo clinical findings to characterize the clinical pharmacokinetics of alisporivir and further assess the magnitude of drug-drug interactions. Incorporated with absorption, distribution, elimination, and TDI data, the model accurately predicted AUC, Cmax, and tmax values after single or multiple doses of alisporivir with a prediction deviation within ± 32%. The model predicted an alisporivir AUC increase by 9.4-fold and a decrease by 86% when alisporivir was co-administrated with ketoconazole (CYP3A4 inhibitor) or rifampin (CYP3A4 inducer), respectively. Predictions were within ± 20% of the observed changes. In conclusion, the PBPK model successfully predicted the alisporivir PK and the magnitude of drug-drug interactions.

Application of physiologically based absorption modeling to formulation development of a low solubility, low permeability weak base: mechanistic investigation of food effect.

Physiologically based pharmacokinetic (PBPK) modeling has been broadly used to facilitate drug development, hereby we developed a PBPK model to systematically investigate the underlying mechanisms of the observed positive food effect of compound X (cpd X) and to strategically explore the feasible approaches to mitigate the food effect. Cpd X is a weak base with pH-dependent solubility; the compound displays significant and dose-dependent food effect in humans, leading to a nonadherence of drug administration. A GastroPlus Opt logD Model was selected for pharmacokinetic simulation under both fasted and fed conditions, where the biopharmaceutic parameters (e.g., solubility and permeability) for cpd X were determined in vitro, and human pharmacokinetic disposition properties were predicted from preclinical data and then optimized with clinical pharmacokinetic data. A parameter sensitivity analysis was performed to evaluate the effect of particle size on the cpd X absorption. A PBPK model was successfully developed for cpd X; its pharmacokinetic parameters (e.g., C max, AUCinf, and t max) predicted at different oral doses were within ±25% of the observed mean values. The in vivo solubility (in duodenum) and mean precipitation time under fed conditions were estimated to be 7.4- and 3.4-fold higher than those under fasted conditions, respectively. The PBPK modeling analysis provided a reasonable explanation for the underlying mechanism for the observed positive food effect of the cpd X in humans. Oral absorption of the cpd X can be increased by reducing the particle size (<100 nm) of an active pharmaceutical ingredient under fasted conditions and therefore, reduce the cpd X food effect correspondingly.

Utility of physiologically based modeling and preclinical in vitro/in vivo data to mitigate positive food effect in a BCS class 2 compound.

Physiologically based pharmacokinetic (PBPK) modeling has become a useful tool to estimate the performance of orally administrated drugs. Here, we described multiple in silico/in vitro/in vivo tools to support formulation development toward mitigating the positive food effect of NVS123, a weak base with a pH-dependent and limited solubility. Administered orally with high-fat meal, NVS123 formulated as dry filled capsules displayed a positive food effects in humans. Three alternative formulations were developed and assessed in in vitro and in vivo preclinical and/or clinical studies. By integrating preclinical in vitro and in vivo data, the PBPK model successfully estimated the magnitude of food effects and the predicted values were within ± 30% of the observed results. A model-guided parameter sensitivity analysis illustrated that enhanced solubility and longer precipitation times under fed condition were the main reason for enhanced NVS123's exposure in presence of food. Eventually, exposure after an amorphous formulation was found to be not significantly altered because of remarkably enhanced intestinal solubility and reduced precipitation. Gastroplus population simulations also suggested that the amorphous formulation is promising in mitigating a clinically significant food effect. Overall, these efforts supported the rationale of clinical investigation of the new formulation, and more importantly, highlighted a practical application of PBPK modeling solving issues of undesirable food effects in weakly basic compounds based on preclinical in vitro/in vivo data.

A simplified PBPK modeling approach for prediction of pharmacokinetics of four primarily renally excreted and CYP3A metabolized compounds during pregnancy.

During pregnancy, a drug's pharmacokinetics may be altered and hence anticipation of potential systemic exposure changes is highly desirable. Physiologically based pharmacokinetics (PBPK) models have recently been used to influence clinical trial design or to facilitate regulatory interactions. Ideally, whole-body PBPK models can be used to predict a drug's systemic exposure in pregnant women based on major physiological changes which can impact drug clearance (i.e., in the kidney and liver) and distribution (i.e., adipose and fetoplacental unit). We described a simple and readily implementable multitissue/organ whole-body PBPK model with key pregnancy-related physiological parameters to characterize the PK of reference drugs (metformin, digoxin, midazolam, and emtricitabine) in pregnant women compared with the PK in nonpregnant or postpartum (PP) women. Physiological data related to changes in maternal body weight, tissue volume, cardiac output, renal function, blood flows, and cytochrome P450 activity were collected from the literature and incorporated into the structural PBPK model that describes HV or PP women PK data. Subsequently, the changes in exposure (area under the curve (AUC) and maximum concentration (C max)) in pregnant women were simulated. Model-simulated PK profiles were overall in agreement with observed data. The prediction fold error for C max and AUC ratio (pregnant vs. nonpregnant) was less than 1.3-fold, indicating that the pregnant PBPK model is useful. The utilization of this simplified model in drug development may aid in designing clinical studies to identify potential exposure changes in pregnant women a priori for compounds which are mainly eliminated renally or metabolized by CYP3A4.

Case studies for practical food effect assessments across BCS/BDDCS class compounds using in silico, in vitro, and preclinical in vivo data.

Practical food effect predictions and assessments were described using in silico, in vitro, and/or in vivo preclinical data to anticipate food effects and Biopharmaceutics Classification System (BCS)/Biopharmaceutics Drug Disposition Classification System (BDDCS) class across drug development stages depending on available data: (1) limited in silico and in vitro data in early discovery; (2) preclinical in vivo pharmacokinetic, absorption, and metabolism data at candidate selection; and (3) physiologically based absorption modeling using biorelevant solubility and precipitation data to quantitatively predict human food effects, oral absorption, and pharmacokinetic profiles for early clinical studies. Early food effect predictions used calculated or measured physicochemical properties to establish a preliminary BCS/BDDCS class. A rat-based preclinical BCS/BDDCS classification used rat in vivo fraction absorbed and metabolism data. Biorelevant solubility and precipitation kinetic data were generated via animal pharmacokinetic studies using advanced compartmental absorption and transit (ACAT) models or in vitro methods. Predicted human plasma concentration-time profiles and the magnitude of the food effects were compared with observed clinical data for assessment of simulation accuracy. Simulations and analyses successfully identified potential food effects across BCS/BDDCS classes 1-4 compounds with an average fold error less than 1.6 in most cases. ACAT physiological absorption models accurately predicted positive food effects in human for poorly soluble bases after oral dosage forms. Integration of solubility, precipitation time, and metabolism data allowed confident identification of a compound's BCS/BDDCS class, its likely food effects, along with prediction of human exposure profiles under fast and fed conditions.

Nilotinib preclinical pharmacokinetics and practical application toward clinical projections of oral absorption and systemic availability.

Nilotinib is a highly potent and selective bcr-abl tyrosine kinase inhibitor used for the treatment of patients who are in the chronic and accelerated phases of Philadelphia chromosome-positive (Ph+) chronic myeloid leukemia (CML). Nilotinib preclinical data and its use for practical predictions of systemic exposure profiles and oral absorption are described. The systemic clearance (CL) of nilotinib was relatively low in rodents with a value of less than 25% of hepatic blood flow (Q(H)), while it was moderate in monkeys and dogs (CL/Q(H) = 32-35%). The steady state volume of distribution (V(ss) ) ranged from 0.55 to 3.9 l/kg across the species tested. The maximum concentration (C(max)) of nilotinib occurred at 0.5-4 h and the bioavailability was moderate (17-44%). The plasma protein binding was high (> 97.5%) in preclinical species and humans. The human CL (~ 0.1 l/h/kg) and V(ss) (~2.0 l/kg) were best predicted by the rat-dog-human proportionality method and allometric scaling method, respectively. The human intravenous pharmacokinetic profile was projected by the Wajima 'C(ss)-MRT' method. The predicted micro-constants from human intravenous profiles were incorporated into the advanced compartmental absorption and transit model within the GastroPlus program to simulate the oral concentration-time curves in humans. Overall, the simulated oral human pharmacokinetic profiles showed good agreement with observed clinical data, and the model predicted that the C(max) , AUC, t(½) , V(z) /F and CL/F values were within 1.3-fold of the observed values. The absolute oral bioavailability of nilotinib in healthy humans was predicted to be low (< 25%).

Novel physiologically based pharmacokinetic modeling of patupilone for human pharmacokinetic predictions.

PURPOSE: Patupilone (EPO906) is a novel potent microtubule stabilizer, which has been evaluated for cancer treatment. A novel physiologically based pharmacokinetics (PBPK) model was developed based on nonclinical data to predict the disposition of patupilone in cancer patients. METHODS: After a single intravenous dose (1.2 mg/kg) in male Han-Wistar rats, the tissue distribution of (14)C-patupilone was investigated by quantitative whole-body autoradiography (QWBA). The blood radioactivity and patupilone concentration were determined by LC-MS/MS and liquid scintillation counting. A novel PBPK model was developed based on rat tissue concentration data to predict blood concentration-time profiles of patupilone in cancer patients. PBPK parameters derived from the rat were applied to a human PBPK model. Phase I clinical pharmacokinetic data in Caucasian and Japanese cancer patients at various doses ranging from 0.75 to 10 mg/m(2) were successfully described using the PBPK approach. RESULTS: Patupilone dispositions in lung, heart, muscle, spleen, liver, brain, adipose, and testes of rats were well described using the PBPK model developed assuming a perfusion rate-limited distribution between different compartments. For skin and bone marrow, concentration-time profiles were modeled assuming a permeability-limited distribution between different compartments. The simulated human pharmacokinetic profiles from the PBPK model showed good agreement with observed clinical pharmacokinetic data, where the model predicted AUC, t(1/2), V(ss), and CL values were within approximately twofold of the observed values for all dose groups. CONCLUSIONS: The distribution of patupilone in rats was well described by a PBPK model based on measured tissue distribution profiles generated by QWBA combined with metabolism data. The human PBPK model adequately predicted blood pharmacokinetics of patupilone in cancer patients. The PBPK model based upon preclinical tissue distribution data can aid in successful prediction of pharmacokinetics in humans.

Preclinical pharmacokinetics and metabolism of MNP001, a piperidine analog of 3-carbamyl compounds.

MNP001 is a newly synthesized 3-carbamyl-4-methylpyrrole analog with dual pharmacophores simultaneously to inhibit phosphodiesterase type 4 (PDE4) and to antagonize L-type calcium channels. The physicochemical properties of MNP001, including solubility, pKa, Log P, plasma protein binding and plasma/blood partitioning, were determined to support the pharmacokinetic characterization. The preclinical pharmacokinetic parameters were determined in an in vivo rat model and the metabolic pathways of MNP001 were characterized by incubating the compound in vitro in rat or human microsomes/supersomes cocktails. MNP001 was found to have a low solubility in simulated intestinal fluid but a high solubility in simulated gastric fluid. MNP001 is a highly lipophilic compound with a Log P value greater than 4. MNP001 was highly bound to the plasma protein and had an uneven partition between red blood cells and plasma. MNP001 exhibited a rapid absorption, broad distribution, slow systemic clearance and a low but pharmacologically relevant oral bioavailability in rats. The low oral bioavailability was possibly caused by the low aqueous solubility of MNP001 in the gastrointestinal tract. However, 8 h after oral dosing, the mean plasma level of MNP001 was able to remain about 2-fold greater than the minimum effective concentration. The major metabolite of MNP001 was defined as a tetrahydropyridine product (MNP001-M4) of CYP3A4-mediated phase I oxidation. The possibility that the major metabolite MNP001-M4 may have a comparable antihypertensive efficacy to MNP001 needs to be studied.

HPLC/MS/MS analysis of 3-carbamyl-4-methylpyrrole analog MNP001, a highly potent antihypertensive agent, in rat plasma.

Chemically synthesized 3-carbamyl-4-methylpyrroles were characterized as a group of antihypertensive agents with dual-targeting mechanism to simultaneously inhibit type 4 phosphodiesterase (PDE4) and L-type calcium channels. A 5-butyl analog of the pyrrole family, MNP001, was found to have high potency in reducing animal blood pressure and heart rate. A method for measuring MNP001 using high performance liquid chromatography combined with tandem mass spectrometry (HPLC/MS/MS) was developed. The calibration curve for MNP001 showed good linearity with the value of correlation coefficient greater than 0.987 over the range of 0.25-500 ng/mL. The results for inter-day and intra-day precision as well as accuracy were acceptable according to the criteria established by FDA. The lower limit of quantification was 0.25 ng/mL. This method was quick, sensitive and sufficient for in vivo pharmacokinetic and pharmacodynamic studies on this novel antihypertensive pyrrole compound.