Bioequivalence evaluation of lansoprazole 30-mg capsules (Lanfast and Lanzor) in healthy volunteers

Pharmacodynamics and Pharmacokinetics of a New Type of Compound Lansoprazole Capsule in Gastric Ulcer Rats and Beagle Dogs: Importance of Adjusting Oxidative Stress and Inflammation

The aim of this study was to investigate the pharmacodynamics and pharmacokinetics of a new type of compound lansoprazole capsule in gastric ulcer rats and beagle dogs in order to confirm whether it is more effective in treating gastric ulcers and its rapid absorption. A rat model of gastric ulcers was used to evaluate the anti-ulcerogenic effect of the compound lansoprazole capsule. A fast and sensitive UPLC-MS/MS method was developed to detect lansoprazole in dog plasma. Macroscopic and histological evaluation results revealed that the compound lansoprazole capsule is more effective in treating gastric ulcers as it was able to significantly reduce the gastric ulcer compared to the other groups. Additionally, it was able to enhance the expression of the antioxidant enzyme superoxide dismutase (SOD) and suppress lipid peroxidation as indicated by the reduction of malondialdehyde (MDA) and H⁺-K⁺-ATP activity. Furthermore, this capsule increased the expression of mucosal vascular endothelial growth factor (VEGF) and cyclic oxygenase 2 (COX-2). The established UPLC-MS/MS method was successfully applied to the evaluation of pharmacokinetic parameters of lansoprazole in beagle dogs. The results indicate that the compound lansoprazole capsule had an advantage of rapid absorption. This study demonstrated that the compound lansoprazole capsule has better gastroprotective activity and that this might be related to its positive influence on oxidative stress and inflammation. This new type of compound lansoprazole capsule may be potentially useful in preclinical therapy.

Investigation of the bioequivalence of two lansoprazole formulations in healthy Chinese volunteers after a single oral administration

The objective of this study was to compare two lansoprazole products (the reference brand enteric-coated capsules and the test generic enteric-coated tablets), and the key pharmacokinetic (PK) parameters for both formulations and their metabolites were assessed. The study used an open-label, randomized two-period crossover design with an 8-day washout period between doses in 24 healthy subjects under fasting conditions. The concentration of lansoprazole and its two metabolites was determined using liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. The in vitro release of lansoprazole from the test and reference formulations was within the acceptable limits. The relationship between concentration and peak area ratio was found to be linear within the range for lansoprazole and metabolites. The point estimates (ratios of geometric mean) of lansoprazole and two main metabolites were between 94.3% and 105.1% for AUC_0-t, AUC_0-∞, and C_max. No statistically significant difference between the two formulations was found. The results of in vitro and in vivo suggested equivalent clinical efficacy of the two brands.

Eudragit L/HPMCAS blend enteric-coated lansoprazole pellets: enhanced drug stability and oral bioavailability

The objectives of the present work were to use blends of Eudragit L and hydroxypropyl methylcellulose acetate succinate (HPMCAS) as enteric film coatings for lansoprazole (LSP) pellets. The enteric-coated pellets were prepared with a fluid-bed coater. The influence of the blend ratio, type of plasticizer, plasticizer level, coating level, and curing conditions on gastric stability in vitro drug release and drug stability was evaluated. Furthermore, the bioavailability of the blend-coated pellets in beagle dogs was also performed. The blend-coated pellets exhibited significant improvement of gastric stability and drug stability compared to the pure polymer-coated pellets. Moreover, the AUC values of blend-coated pellets were greater than that of the pure polymer-coated pellets. It was concluded that the using blends of Eudragit L and HPMCAS as enteric film coatings for LSP pellets improved the drug stability and oral bioavailability.

Prediction of inter-individual variability in the pharmacokinetics of CYP2C19 substrates in humans

Significant inter-individual variability of exposure for CYP2C19 substrates may be only partly due to genetic polymorphism. Therefore, the in vivo inter-individual variability in hepatic intrinsic clearance (CL(int,h)) of CYP2C19 substrates was estimated from reported AUC values using Monte Carlo simulations. The coefficient of variation (CV) for CL(int,h) in poor metabolizers (PM) expected from genotypes CYP2C19*2/*2, CYP2C19*3/*3 or CYP2C19*2/*3 was estimated as 25.8% from the CV for AUC of omeprazole in PMs. With this, CVs of CL(int,h) in extensive metabolizers (EM: CYP2C19*1/*1), intermediate metabolizers (IM: CYP2C19*1/*2 or *3) and ultra-rapid metabolizers (UM), CYP2C19*17/*17 and *1/*17, were estimated as 66.0%, 55.8%, 6.8% and 48.0%, respectively. To validate these CVs, variability in the AUC of CYP2C19 substrates lansoprazole and rabeprazole, partially metabolized by CYP3A4 in EMs and IMs, were simulated using the CV in CL(int,h) for CYP2C19 EMs and IMs and 33% of the CV previously reported for CYP3A4. Published values were within 2.5-97.5 percentile range of simulated CVs for the AUC. Furthermore, simulated CVs for the AUC of omeprazole and lansoprazole in ungenotyped populations were comparable with published values. Thus, estimated CL(int,h) variability can predict variability in the AUC of drugs metabolized not only by CYP2C19 but also by multiple enzymes.

Modeling chemical interaction profiles: II. Molecular docking, spectral data-activity relationship, and structure-activity relationship models for potent and weak inhibitors of cytochrome P450 CYP3A4 isozyme

Polypharmacy increasingly has become a topic of public health concern, particularly as the U.S. population ages. Drug labels often contain insufficient information to enable the clinician to safely use multiple drugs. Because many of the drugs are bio-transformed by cytochrome P450 (CYP) enzymes, inhibition of CYP activity has long been associated with potentially adverse health effects. In an attempt to reduce the uncertainty pertaining to CYP-mediated drug-drug/chemical interactions, an interagency collaborative group developed a consensus approach to prioritizing information concerning CYP inhibition. The consensus involved computational molecular docking, spectral data-activity relationship (SDAR), and structure-activity relationship (SAR) models that addressed the clinical potency of CYP inhibition. The models were built upon chemicals that were categorized as either potent or weak inhibitors of the CYP3A4 isozyme. The categorization was carried out using information from clinical trials because currently available in vitro high-throughput screening data were not fully representative of the in vivo potency of inhibition. During categorization it was found that compounds, which break the Lipinski rule of five by molecular weight, were about twice more likely to be inhibitors of CYP3A4 compared to those, which obey the rule. Similarly, among inhibitors that break the rule, potent inhibitors were 2–3 times more frequent. The molecular docking classification relied on logistic regression, by which the docking scores from different docking algorithms, CYP3A4 three-dimensional structures, and binding sites on them were combined in a unified probabilistic model. The SDAR models employed a multiple linear regression approach applied to binned 1D ¹³C-NMR and 1D ¹⁵N-NMR spectral descriptors. Structure-based and physical-chemical descriptors were used as the basis for developing SAR models by the decision forest method. Thirty-three potent inhibitors and 88 weak inhibitors of CYP3A4 were used to train the models. Using these models, a synthetic majority rules consensus classifier was implemented, while the confidence of estimation was assigned following the percent agreement strategy. The classifier was applied to a testing set of 120 inhibitors not included in the development of the models. Five compounds of the test set, including known strong inhibitors dalfopristin and tioconazole, were classified as probable potent inhibitors of CYP3A4. Other known strong inhibitors, such as lopinavir, oltipraz, quercetin, raloxifene, and troglitazone, were among 18 compounds classified as plausible potent inhibitors of CYP3A4. The consensus estimation of inhibition potency is expected to aid in the nomination of pharmaceuticals, dietary supplements, environmental pollutants, and occupational and other chemicals for in-depth evaluation of the CYP3A4 inhibitory activity. It may serve also as an estimate of chemical interactions via CYP3A4 metabolic pharmacokinetic pathways occurring through polypharmacy and nutritional and environmental exposures to chemical mixtures.

Pharmacokinetic properties of lansoprazole (30-mg enteric-coated capsules) and its metabolites: A single-dose, open-label study in healthy Chinese male subjects

BACKGROUND

Lansoprazole, a benzimidazole derivative, is indicated for the treatment of various peptic diseases. It is metabolized mainly in the liver, and its primary active metabolites present in plasma are 5'-hydroxy lansoprazole and lansoprazole sulfone. Few data are available on the pharmacokinetic properties of lansoprazole, 5'-hydroxy lansoprazole, and lansoprazole sulfone, which can be used to measure cytochrome P450 (CYP) 2C19 activity.

OBJECTIVES

The aims of this study were to investigate the clinical plasma pharmacokinetic properties of lansoprazole and its metabolites in healthy Chinese male volunteers, and to assess the influences of CYP2C19 on the pharmacokinetics of lansoprazole.

METHODS

Healthy adult Chinese male volunteers were enrolled in this single-dose, open-label study. All patients received a single oral enteric capsule containing 30 mg of lansoprazole after a 12-hour overnight fast. Serial blood samples were collected immediately before (0 hour) and at 20, 40, 60, 90, 120, and 150 minutes and 3, 4, 6, 8, 10, 12, 15, and 24 hours after study drug administration. The plasma concentrations of lansoprazole, 5'-hydroxy lansoprazole, and lansoprazole sulfone were determined using a validated internal standard high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method. Pharmacokinetic properties (including Cmax, Tmax, elimination t½ [t½z], mean residence time [MRT], AUC0-24, AUC0-∞, apparent oral clearance [CLz/F], and apparent volume of distribution [Vz/F]) were determined using the noncompartmental method.

RESULTS

Twenty volunteers (mean [SD] age, 34.9 [2.9] years; weight, 64.6 [2.2] kg; height, 171.3 [3.3] cm) were enrolled in and completed the study. The mean (SD) pharmacokinetic properties of lansoprazole were as follows: Cmax, 1047 (344) ng/mL; Tmax, 2.0 (0.7) hours; t½z, 2.24 (1.43) hours; MRT, 3.62 (0.87) hours; AUC0-24, 3388 (1484) ng/mL/h; AUC0-∞, 3496 (1693) ng/mL/h; CLz/F, 9.96 (3.74) L/h; and Vz/F, 32.83 (11.74) L. The findings with 5'-hydroxy lansoprazole and lansoprazole sulfone, respectively, were as follows: Cmax, 111.2 (41.8) and 66.6 (52.9) ng/mL; Tmax, 2.1 (0.8) and 1.9 (0.8) hours; t½z, 2.31 (1.18) and 2.52 (1.54) hours; and AUC0-24, 317.0 (81.2) and 231.9 (241.7) ng/mL/h. No adverse events were reported throughout the study.

CONCLUSIONS

In these healthy Chinese male volunteers administered a single oral dose of lansoprazole 30 mg, absorption of lansoprazole was rapid (mean Cmax, 1047 ng/mL; Tmax, ~2.0 hours). Its 2 primary active metabolites, 5'-hydroxy lansoprazole and lansoprazole sulfone, were identified in measurable quantities in plasma (Cmax, 111.2 and 66.6 ng/mL, respectively; and Tmax, 2.1 and 1.9 hours). The plasma t½z did not appear to reflect the duration of suppression of gastric acid secretion: the t½z values of lansoprazole and the 2 metabolites were ~2 to 2.5 hours, while the acid-inhibitory effect lasted >24 hours. Cmax, AUC, and t½z of lansoprazole, and especially lansoprazole sulfone, varied. Differences in metabolism types and/or genotype of CYP2C19 should be taken into account when planning a lansoprazole dosing regimen.

Simultaneous determination of lansoprazole enantiomers and their metabolites in plasma by liquid chromatography with solid-phase extraction

A simple and highly sensitive high-performance liquid chromatography (HPLC) method for the simultaneous quantitative determination of lansoprazole enantiomers and their metabolites, 5-hydroxylansoprazole enantiomers and lansoprazole sulfone, in human plasma have been developed. Chromatographic separation was achieved with a Chiral CD-Ph column using a mobile phase of 0.5M NaClO(4)-acetonitrile-methanol (6:3:1 (v/v/v)). The analysis required only 100 microl of plasma and involved a solid-phase extraction with Oasis HLB cartridge, with a high extraction recovery (>94.1%) and good selectivity. The lower limit of quantification (LOQ) of this assay was 10 ng/ml for each enantiomer of both lansoprazole and 5-hydroxylansoprazole, and 5 ng/ml for lansoprazole sulfone. The coefficient of variation of inter- and intra-day assay was <8.0% and accuracy was within 8.4% for all analytes (concentration range 10-1000 ng/ml). The linearity of this assay was set between 10 and 1000 ng/ml (r2>0.999 of the regression line) for each of the five analytes. This method is applicable for accurate and simultaneous monitoring of the plasma levels of lansoprazole enantiomers and their metabolites in the renal transplant recipients.

Lansoprazole quantification in human plasma by liquid chromatography-electrospray tandem mass spectrometry

An analytical method based on liquid chromatography with positive ion electrospray ionization (ESI) coupled to tandem mass spectrometry detection was developed for the determination of lansoprazole in human plasma using omeprazole as the internal standard. The analyte and internal standard were extracted from the plasma samples by liquid-liquid extraction using diethyl-ether-dichloromethane (70:30; v/v) and chromatographed on a C(18) analytical column. The mobile phase consisted of acetonitrile-water (90:10; v/v)+10 mM formic acid. The method has a chromatographic total run time of 5 min and was linear within the range 2.5-2000 ng/ml. Detection was carried out on a Micromass triple quadrupole tandem mass spectrometer by Multiple Reaction Monitoring (MRM). The intra- and inter-run precision, calculated from quality control (QC) samples, was less than 3.4%. The accuracy as determined from QC samples was less than 9%. The method herein described was employed in a bioequivalence study of two capsule formulations of lansoprazole.