Pharmacokinetic bioequivalence crossover study of branded generic and innovator formulations of the cholesterol lowering agent ezetimibe

Comparison of pharmacokinetics of a fixed-dose combination of atorvastatin/ezetimibe 5 mg/10 mg versus separate tablets in healthy subjects

The 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors are well-established treatment options for dyslipidemia. For patients not meeting low-density lipoprotein cholesterol targets with monotherapy, combination therapy with another lipid-lowering agent including ezetimibe, is recommended. This study compared the pharmacokinetics (PKs) and safety of a fixed-dose combination (FDC) of atorvastatin/ezetimibe 5 mg/10 mg with the individual components in healthy Korean subjects. A randomized, open-label, single-dose, 2-treatment, 2-sequence, crossover study was conducted in 60 healthy subjects. An FDC of atorvastatin/ezetimibe 5 mg/10 mg or the corresponding individual components was administered in the first period, and the alternative in the second period after a 14-day washout. Serial blood samples were collected up to 72 hours post-dose to calculate PK parameters such as maximum plasma concentration (Cmax) and the area under the plasma concentration-time curve to the last measurable concentration (AUClast). The geometric mean ratios (GMRs) and 90% confidence intervals (CIs) of the Cmax and AUClast for the atorvastatin and total ezetimibe were estimated compared to the individual components. Adverse events (AEs) and other safety variables were monitored to evaluate safety and tolerability profile. Sixty subjects were enrolled and 58 subjects completed the study. For atorvastatin, the GMRs (90% CIs) for Cmax and AUClast were 1.18 (1.04-1.33) and 1.04 (1.00-1.08), respectively, and the corresponding values were 1.37 (1.26-1.50) and 0.98 (0.93-1.03) for total ezetimibe. No clinically significant treatment-emergent AEs were observed with either formulations. The FDC of atorvastatin/ezetimibe 5 mg/10 mg was safe and showed similar exposure to those of the individual components.

Trial Registration

ClinicalTrials.gov Identifier: NCT05202405.

Pharmacokinetic Simulation and Area under the Curve Estimation of Drugs Subject to Enterohepatic Circulation

Enterohepatic circulation (EHC) is a complex process where drugs undergo secretion and reabsorption from the intestinal lumen multiple times, resulting in pharmacokinetic profiles with multiple peaks. The impact of EHC on area under the curve (AUC) has been a topic of extensive debate, questioning the suitability of conventional AUC estimation methods. Moreover, a universal model for accurately estimating AUC in EHC scenarios is lacking. To address this gap, we conducted a simulation study evaluating five empirical models under various sampling strategies to assess their performance in AUC estimation. Our results identify the most suitable model for EHC scenarios and underscore the critical role of meal-based sampling strategies in accurate AUC estimation. Additionally, we demonstrate that while the trapezoidal method performs comparably to other models with a large number of samples, alternative models are essential when sample numbers are limited. These findings not only illuminate how EHC influences AUC but also pave the way for the application of empirical models in real-world drug studies.

Pharmacokinetics and Bioequivalence of Fixed-Dose Combination of Simvastatin and Ezetimibe Tablets: A Randomized, Crossover, Open-Label Study in Healthy Volunteers

The current study aimed to evaluate the bioequivalence of a new generic combination of simvastatin and ezetimibe with the reference formulation. An open-label, randomized, 3-period, 3-sequence, crossover study, including 60 healthy volunteers, was implemented. Participants received the test and reference formulation, each containing 20 mg of simvastatin and 10 mg of ezetimibe as a single-dose tablet, separated by a minimum of 2-week washout periods. Blood samples were collected for 20 time points from predose to 72 hours after the dose. The total ezetimibe assay was carried out using a validated liquid chromatography-tandem mass spectrometry, while unconjugated ezetimibe, simvastatin, and simvastatin β-hydroxy acid determination was done via a validated ultra-performance liquid chromatography-tandem mass spectrometry. Each assay was preceded by a liquid-liquid extraction step. The pharmacokinetic parameters were derived using noncompartmental analysis and then compared between the reference and test formulations via a multivariate analysis of variance. No statistical difference was found in under the concentration-time curve from time 0 to the last quantifiable concentration and maximum concentration of unconjugated ezetimibe, total ezetimibe, and simvastatin between the reference and test formulations. The 90% confidence intervals of unconjugated ezetimibe, total ezetimibe, and simvastatin natural log-transformed under the concentration-time curve from time 0 to the last quantifiable concentration, and maximum concentration were in the range of 80%-125% as per the bioequivalence acceptance criteria. Therefore, the test formulation was bioequivalent to the reference formulation.

Anti-Inflammatory Effects of Lipid-Lowering Drugs and Supplements-A Narrative Review

Cardiovascular diseases (CVD) are the leading cause of death worldwide. Since the establishment of the "lipid hypothesis", according to which, cholesterol level is directly correlated to the risk of CVD, many different lipid-lowering agents have been introduced in clinical practice. A majority of these drugs, in addition to their lipid-lowering properties, may also exhibit some anti-inflammatory and immunomodulatory activities. This hypothesis was based on the observation that a decrease in lipid levels occurs along with a decrease in inflammation. Insufficient reduction in the inflammation during treatment with lipid-lowering drugs could be one of the explanations for treatment failure and recurrent CVD events. Thus, the aim of this narrative review was to evaluate the anti-inflammatory properties of currently available lipid-lowering medications including statins, ezetimibe, bile acid sequestrants (BAS), proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, fibrates, omega-3 fatty acids, and niacin, as well as dietary supplements and novel drugs used in modern times.

Generic versus brand-name drugs used in cardiovascular diseases

This meta-analysis aimed to compare the efficacy and adverse events, either serious or mild/moderate, of all generic versus brand-name cardiovascular medicines. We searched randomized trials in MEDLINE, Scopus, EMBASE, Cochrane Controlled Clinical Trial Register, and ClinicalTrials.gov (last update December 1, 2014). Attempts were made to contact the investigators of all potentially eligible trials. Two investigators independently extracted and analyzed soft (including systolic blood pressure, LDL cholesterol, and others) and hard efficacy outcomes (including major cardiovascular adverse events and death), minor/moderate and serious adverse events. We included 74 randomized trials; 53 reported ≥1 efficacy outcome (overall sample 3051), 32 measured mild/moderate adverse events (n = 2407), and 51 evaluated serious adverse events (n = 2892). We included trials assessing ACE inhibitors (n = 12), anticoagulants (n = 5), antiplatelet agents (n = 17), beta-blockers (n = 11), calcium channel blockers (n = 7); diuretics (n = 13); statins (n = 6); and others (n = 3). For both soft and hard efficacy outcomes, 100 % of the trials showed non-significant differences between generic and brand-name drugs. The aggregate effect size was 0.01 (95 % CI -0.05; 0.08) for soft outcomes; -0.06 (-0.71; 0.59) for hard outcomes. All but two trials showed non-significant differences in mild/moderate adverse events, and aggregate effect size was 0.07 (-0.06; 0.20). Comparable results were observed for each drug class and in each stratified meta-analysis. Overall, 8 serious possibly drug-related adverse events were reported: 5/2074 subjects on generics; 3/2076 subjects on brand-name drugs (OR 1.69; 95 % CI 0.40-7.20). This meta-analysis strengthens the evidence for clinical equivalence between brand-name and generic cardiovascular drugs. Physicians could be reassured about prescribing generic cardiovascular drugs, and health care organization about endorsing their wider use.