FormalPara Key Points

This study demonstrated that the newly developed fixed-dose combination product (FDCP) of amlodipine, losartan, ezetimibe, and rosuvastatin showed pharmacokinetic profiles comparable to those of the individual tablets, with the geometric mean ratios for Cmax and AUC within the acceptable range of 0.8–1.25 for all six analytes.

Both the FDCP and the individual tablets were well tolerated among participants, with no clinically significant changes in vital signs, physical, biochemical, hematological, electrocardiographic, or urinalysis findings, and no serious adverse events reported, suggesting a favorable safety and tolerability profile.

1 Introduction

Ischemic heart disease is the leading cause of premature death [1]. Strong relationships among high blood pressure, increased serum cholesterol levels, and mortality due to coronary heart disease are known, highlighting the importance of the management of hypertension and dyslipidemia [2]. High blood pressure and high total cholesterol account for 53% and 29% of worldwide ischemic heart disease disability-adjusted life years, respectively [3].

Primary agents used to treat hypertension include thiazide diuretics, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and calcium channel blockers. A combination of two agents is recommended for the treatment of patients who cannot achieve the target blood pressure with a single therapy or for the initial treatment of patients with stage 2 hypertension [4]. For dyslipidemia, statins are recommended as the first-line therapy, while a combination with ezetimibe is recommended if the goals are not achieved with the maximum tolerated statin dose [5]. When ezetimibe was added to stable rosuvastatin, low-density lipoproteins (LDL) levels decreased by 21% [6].

Adherence to cardiovascular drugs is important because low adherence is associated with an increased risk of cardiovascular disease and mortality [7]. A study found a 37% reduced risk of cardiovascular outcomes in compliant patients compared with patients with at least one episode of antihypertensive treatment discontinuation [8]. Another study reported that low statin adherence was associated with increased mortality, with a relative risk of 1.71 [9].

One reason for noncompliance is an increased pill count, and less adherence is expected as the pill count increases [10]. Introducing a fixed-dose combination product (FDCP) may be a promising approach for reducing the pill burden. Several studies have revealed better compliance with the use of FDCP than that with the use of corresponding individual drug combinations [11,12,13]. Especially for hypertension and dyslipidemia, a meta-analysis reported that a single pill count was associated with improved adherence and persistence to the drug as well as favorable clinical outcomes, such as a higher number of patients reaching blood pressure goals and reduced hospitalization or emergency room visits, compared with individual drug combinations [14].

HCP1701 (Amosartan® XQ tablet) is the first FDCP that combines four drugs (amlodipine, losartan, ezetimibe, and rosuvastatin) and targets patients with both hypertension and dyslipidemia. This study aimed to evaluate and compare the pharmacokinetics, safety, and tolerability of amlodipine, losartan, ezetimibe, and rosuvastatin as FDCP and separate tablets.

2 Methods

2.1 Participants

A total of 60 healthy male participants aged 19–45 years with a body mass index (BMI) of 18.5–29.9 kg/m2 were enrolled in the study after they agreed to participate and provided written informed consent. Participants were considered healthy after a physical examination by physicians, 12-lead electrocardiogram (ECG), vital signs, and clinical laboratory tests. Exclusion criteria included participants with clinically significant active disease or history that may affect the pharmacokinetics of drugs; participants who had an allergic history to the investigational drugs; participants whose transaminase aspartate aminotransferase/alanine aminotransferase (AST/ALT) was above 2.5-fold the upper normal limit, creatinine clearance below 80 mL/min, or QTc prolongation > 450 ms; and use of any medication ethical pharmaceuticals (ETC within 14 days and over-the-counter (OTC) within 10 days). The study protocol was approved (IRB no. 2018AN0310, clinicaltrial.gov; NCT04322266) by the Institutional Review Board of Anam Hospital, Korea University Medical Center (Seoul, Korea), and all procedures were conducted in accordance with the principles described in the Declaration of Helsinki and Good Clinical Practice guidelines.

2.2 Study Design

This was an open-label, randomized, single-dose crossover study. Eligible participants were randomized into one of two sequences: sequence 1 [period 1: individual components (ICs); period 2: FDCP] or sequence 2 (period 1: FDCP; period 2: ICs). Each sequence was administered a single dose of HCP1701 [FDCP, 5 mg amlodipine, 100 mg losartan potassium, 10 mg ezetimibe, and 20 mg rosuvastatin (Hanmi Pharmaceuticals, Seoul, Korea)] or a single dose of individual tablets consisting of amlodipine 5 mg [HGP0904, Norvasc Tab. 5 mg (Pfizer Korea, Seoul, Korea)], 100 mg losartan [HGP0608, Cozaar Tab. 100 mg (MSD Korea, Seoul, Korea)], 10 mg ezetimibe, and 20 mg rosuvastatin [HCP1306, Rosuzet Tab. 10/20 mg (Hanmi Pharmaceuticals, Seoul, Korea)]. For FDCP, the investigational products (IPs) were manufactured by Hanmi Pharmaceuticals in accordance with Good Manufacturing Practices (GMP). Their production received approval in Korea after undergoing rigorous evaluation and meeting the stringent criteria set forth by the Korean Ministry of Food and Drug Safety (MFDS). After an overnight fast, 200 mL of water was administered to the participants. The doses of amlodipine, losartan, ezetimibe, and rosuvastatin used in this study are commercially available and are the currently recommended doses for controlling hypertension and hypercholesterolemia.

Blood samples for pharmacokinetic analysis were collected before (0 h) and at 0.33, 0.67, 1, 1.33, 1.67, 2, 3, 4, 5, 6, 8, 10, 12, 24, 48, 72, 96, and 144 h after each dose to assess the pharmacokinetic characteristics of each drug. Safety was assessed by monitoring adverse events, physical examinations, vital signs, clinical laboratory tests, and 12-lead electrocardiogram throughout the study period. There was a 14-day wash-out period between the two periods.

2.3 Determination of Plasma Concentrations

The collected blood samples were centrifuged (at 3000 rpm, 4 ℃) for 15 min for plasma separation. The isolated plasma samples were kept frozen at − 70 ℃ until further analysis. The plasma concentrations of six compounds [amlodipine, losartan, EXP3174 (an active metabolite of losartan), rosuvastatin, free ezetimibe, and total ezetimibe] were determined using high-performance liquid chromatography coupled with tandem mass spectrometry described elsewhere, with minor modifications, following the Korea Ministry of Food and Drug Safety and European Medicines Agency guidelines [15, 16].

2.4 Pharmacokinetic Analysis

Pharmacokinetic parameters were calculated by noncompartmental analysis implemented in PhoenixTM WinNonlin® version 8.0 (Certara Inc., Princeton, NJ, USA). The maximal plasma concentration (Cmax) and time to Cmax (Tmax) were determined directly from the individual concentration–time profiles. The area under the concentration–time curve (AUC) from dosing to the last measurable concentration (AUClast) was calculated using the trapezoidal rule, and the AUC from time zero to infinity (AUCinf) was calculated as AUClast + Clast/ke, where Clast is the last measurable concentration and ke is the terminal elimination rate constant. The t1/2 (half-life) was equal to ln2/ke and the oral clearance (CL/F) was estimated using dose/AUCinf.

2.5 Statistical Analysis

Data are expressed as mean ± standard deviation (SD) unless otherwise indicated. All statistical analyses were performed using SAS 9.4 (SAS Institute, Cary, NC, USA). For the evaluation of pharmacokinetic equivalence, the Cmax and AUC values were log-transformed and then analyzed using a mixed effect model analysis of variance, considering period, sequence, and treatment as fixed effects and sequence-nested participants as a random effect. Point estimates of the geometric mean ratios (GMRs) and two-sided 90% confidence intervals (CIs) were calculated. After comparing the log-transformed data of FDCPs and ICs, 90% CIs of GMR between 0.8 and 1.25 after comparing the log-transformed data of FDCP and ICs were considered bioequivalent according to the US Food and Drug Administration guidelines [17]. Differences were considered statistically significant at P < 0.05.

3 Results

3.1 Participants

Of 74 participants who underwent screening, 60 healthy participants were enrolled in this study. Participants’ demographic characteristics are presented in Table 1. The mean age, weight, and BMI of the participants were 26.0 years, 72.5 kg, 174.8 cm, and 23.7 kg/m2, respectively. Three participants dropped out for personal reasons, and 57 participants completed both study periods.

Table 1 Baseline demographic characteristics (N=60)
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3.2 Comparison of Amlodipine Pharmacokinetics

The mean plasma concentration versus time profiles of amlodipine after treatment with ICs and FDCP are shown in Fig. 1A. When we compared the pharmacokinetic variables of amlodipine between ICs and FDCP, no significant differences were observed (Table 2). The mean Cmax values for amlodipine were 2.98 ng/mL for ICs and 2.93 ng/mL for FDCP, and its AUCinf values were also comparable (IC: 146.53 ng h/mL, FDCP: 142.91 ng h/mL). The estimated values of GMRs (Cmax: 0.9737, AUClast: 0.9664, AUCinf: 0.9717) and 90% CIs for both Cmax and AUCs were within the range of 0.8–1.25, indicating that FDCP and IC tablets were bioequivalent (Table 6).

Fig. 1
figure 1

Mean plasma concentration profiles of amlodipine (A), losartan (B), EXP3174 (C), rosuvastatin (D), free ezetimibe (E), and total ezetimibe (F) after administration of individual components (ICs) and FDCP for amlodipine, losartan, rosuvastatin, and ezetimibe.

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Table 2 Summary of pharmacokinetic variables of amlodipine
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3.3 Comparison of Losartan Pharmacokinetics

The mean plasma concentration versus time profiles of losartan and its active metabolite, EXP3174, after treatment with ICs and FDCP are presented in Figs. 1B, 2C. On comparing the pharmacokinetic variables of losartan and its active metabolite, EXP3174, between ICs and FDCP, no significant differences were observed in the pharmacokinetic parameters (Table 3). The mean Cmax values for losartan and EXP3174 were 608.86 ng/mL and 955.47 ng/mL (ICs) and 590.53 ng/mL 956.02 ng/mL (FDCP), respectively. AUCinf values of losartan and EXP3174 were also comparable without any statistical significance (IC: 936.41 ng h/mL for losartan and 5528.71 ng∙h/mL for EXP3174, FDCP: 988.80 ng∙h/mL for losartan and 5555.40 ng h/mL for EXP3174). The estimated values of GMRs (Cmax: 0.9632, AUClast: 1.0301, and AUCinf: 1.0296 for losartan; Cmax: 0.9995, AUClast: 1.0051, and AUCinf: 1.0044 for EXP3174) and 90% CIs for both Cmax and AUCs of losartan and EXP3174 were all within the range of 0.8–1.25, indicating that FDCP and IC tablets were bioequivalent (Table 6).

Table 3 Summary of pharmacokinetic variables of losartan and its active metabolite, EXP-3174
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3.4 Comparison of Rosuvastatin Pharmacokinetics

The mean plasma concentration versus time profile of rosuvastatin after treatment with ICs and FDCP is shown in Fig. 1D. On assessing the pharmacokinetic variables of rosuvastatin between ICs and FDCP formulations, no significant differences were observed (Table 4). The mean Cmax values for rosuvastatin were 43.91 ng/mL (ICs) and 45.15 ng/mL (FDCP) and its AUCinf values were also comparable (IC: 237.91 ng h/mL, FDCP: 245.29 ng h/mL). The estimated values of GMRs (Cmax: 1.0065, AUClast: 1.0189, AUCinf: 1.0279) and their 90% CIs for both Cmax and AUCs were within the range of 0.8–1.25, indicating that FDCP and IC tablets were bioequivalent (Table 6).

Table 4 Summary of pharmacokinetic variables of rosuvastatin
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3.5 Comparison of Ezetimibe Pharmacokinetics

The mean plasma concentration versus time profiles for free and total ezetimibe after treatment with ICs and FDCP are presented in Fig. 1E, F. On comparing the pharmacokinetic variables between ICs and FDCP, no significant differences were observed (Table 5). The mean Cmax values for free ezetimibe were 7.05 ng/mL (ICs) and 7.07 ng/mL (FDCP) and those for total ezetimibe were 52.96 ng/mL and 52.04 ng/mL, respectively. The AUCinf values of free and total ezetimibe were also similar without any statistical significance (IC: 100.31 ng h/mL for free ezetimibe and 577.00 ng h/mL for total ezetimibe; FDCP: 105.91 ng h/mL for free ezetimibe and 608.09 ng h/mL for total ezetimibe). The estimated GMRs (Cmax: 1.0244, AUClast: 1.0595, AUCinf: 1.0598 for free ezetimibe, Cmax: 1.0029, AUClast: 1.0402, and AUCinf: 1.0479 for total ezetimibe) and 90% CIs for both Cmax and AUCs of free and total ezetimibe were all within the range of 0.8–1.25, indicating that FDCP and IC tablets were bioequivalent (Table 6).

Table 5 Summary of pharmacokinetic variables of free ezetimibe (free and total)
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Table 6 Statistical analysis result for PK equivalence for amlodipine, losartan (and EXP-3174), rosuvastatin, and ezetimibe (free and total)
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3.6 Safety Profiles and Tolerability

No serious adverse events or clinically significant changes were observed during the study period. Four participants experienced adverse events. During the FDCP treatment (test) period, two adverse events were reported: gastroenteritis and viral infection. During the ICs (reference) treatment period, two adverse events were reported: respiratory tract infection and abnormal blood creatinine phosphokinase levels. All adverse events were mild and the patient recovered without treatment. As the FDCP was composed of two antihypertensive drugs (amlodipine and losartan), we compared the variation in blood pressure during the study period. Blood pressure profiles after administration of the investigational drugs were similar between the FDC and ICs (Supplementary Fig. 1). Both systolic and diastolic blood pressures reached their lowest mean values at 8 h post-dose. There were no clinically meaningful findings on vital signs, clinical laboratory tests, 12-lead electrocardiography, or physical examination.

4 Discussion

In this study, we compared the pharmacokinetics of FDCP with those of conventional individual components, specifically amlodipine and losartan, for hypertension treatment, and rosuvastatin and ezetimibe for lowering blood cholesterol levels.

Hypertension is often accompanied by hypercholesterolemia, which is associated with accelerated atherosclerosis [18]. According to a survey in the USA, the prevalence rates of hypertension, hypercholesterolemia, and both are 30%, 47%, and 18%, respectively [19]. The prevalence of blood pressure above 140/90 mmHg and cholesterol above 5.0 mmol/L was 34% in men and 28% in women based on the Monitoring of Trends and Determinants in Cardiovascular Disease surveys [20]. Controlling both risk factors is essential to significantly reduce morbidity and mortality [21]. To develop an FDCP for treating hypertension and hypercholesterolemia, four individual drugs, amlodipine and losartan for hypertension, and ezetimibe and rosuvastatin for hypercholesterolemia, were combined. This study evaluated the pharmacokinetics of amlodipine, losartan, rosuvastatin, and ezetimibe and compared the characteristics of FDCP administration and co-administration of the individual drugs. Safety, tolerability, and blood pressure profiles were also examined.

The study results showed that the pharmacokinetic profiles of amlodipine, losartan, rosuvastatin, and ezetimibe after individual drugs administration were comparable to the FDCP. Systemic exposure to the individual drugs and FDCP forms of amlodipine, losartan, rosuvastatin, and ezetimibe were similar in terms of Cmax and AUC, indicating similar absorption profiles for the two formulations. The pharmacokinetic parameters reported in this study were consistent with those of previous publications, with the shortest Tmax and half-life for losartan and the longest for amlodipine among the analytes [22, 23]. The 14-day washout period was designed to ensure sufficient elimination of amlodipine. The observed half-life of amlodipine was approximately 43 h, allowing for sufficient washout between treatments.

A large intra-subject coefficient of variance (CV) of pharmacokinetic parameters requires a large number of participants to assess bioequivalence in clinical trials. On the basis of the literature, the intra-participant CV for the Cmax of losartan was assumed to be 36.7%, requiring 45 participants to demonstrate bioequivalence with 80% power [24]. Therefore, this study aimed to enroll 60 participants with a dropout rate of 25%. The results of this study showed an intra-participant CV value of 44.31% for the Cmax of losartan, which was the highest among the parameters.

This study assessed the pharmacokinetics of the main active ingredients and metabolites. After rapid absorption, losartan underwent oxidative metabolism to produce EXP3174, an active metabolite that is up to 40 times more potent than the parent compound losartan [25]. Ezetimibe is rapidly absorbed and extensively metabolized by uridine 5′-diphosphate-glucuronosyltransferase enzymes to ezetimibe glucuronide, which is at least as potent as its parent compound [26, 27]. The pharmacokinetic parameters for losartan and ezetimibe as well as their metabolites were comparable, with 90% confidence intervals for geometric mean ratios within the range of 0.8–1.25. These results suggest that the activity of FDCP is comparable to that of the individual products.

FDCP and ICs were well tolerated in this study and their blood pressure profiles were similar. However, as the study was conducted on healthy participants and involved only a single-dose administration, the efficacy of FDCP in patients cannot be conclusively determined. In addition, we only enrolled young male Korean volunteers, which might affect the results. Nevertheless, comparable blood pressure profiles and systemic exposure to the two treatments suggest that their efficacies in patients are likely to be similar.

In summary, this study demonstrated that a newly developed FDCP containing amlodipine, losartan, ezetimibe, and rosuvastatin exhibited pharmacokinetic equivalence with the individual components and met the regulatory criteria in healthy volunteers.