Comparative Pharmacokinetic Study Research Articles

Mixing energy as an adjustment tool for aerodynamic behaviour of an inhaled product: In-vitro and in-vivo effects

This paper describes the development of a fixed dose dry powder combination of indacaterol maleate (Inda) and glycopyrronium bromide (Glyco) in Easyhaler® inhaler for a comparative pharmacokinetic (PK) study, as well as the outcome of such a study. The development aim was to produce formulations with three different in vitro dispersibility profiles for both Inda and Glyco. This so-called ‘rake’ approach allows for quantitation of the candidate formulations relative to the reference product Ultibro® Breezhaler® in terms of the key PK parameters.Three formulations (A, B and C) were produced based on the mixing energy concept. For both APIs, formulation A (lowest mixing energy) displayed the highest fine particle fractions and formulation C (highest mixing energy) the lowest. GMP manufacturing confirmed the performance of the three formulations.The candidate formulations were tested against the reference product in a single dose PK study in healthy volunteers. Clear differences in Inda plasma concentration profiles were observed between the treatments when administered concomitantly with charcoal, with Easyhaler A showing the highest Cmax value and Easyhaler C the lowest. Easyhaler B was bioequivalent to Ultibro Breezhaler with regard to the primary PK parameters of Inda, Cmax and AUC72h. For Glyco, Easyhaler formulations A, B and C provided lower peak concentrations than Ultibro Breezhaler. For AUC72h of Glyco, Easyhaler B was bioequivalent to the reference product. Additional measures for adjustment of formulation performance can be foreseen, whose effects can be predicted based on mixing energy theory.

Comparative Study of Dermal Pharmacokinetics Between Topical Drugs Using Open Flow Microperfusion in a Pig Model

PurposeAccurate methods to determine dermal pharmacokinetics are important to increase the rate of clinical success in topical drug development. We investigated in an in vivo pig model whether the unbound drug concentration in the interstitial fluid as determined by dermal open flow microperfusion (dOFM) is a more reliable measure of dermal exposure compared to dermal biopsies for seven prescription or investigational drugs. In addition, we verified standard dOFM measurement using a recirculation approach and compared dosing frequencies (QD versus BID) and dose strengths (high versus low drug concentrations).MethodsDomestic pigs were topically administered seven different drugs twice daily in two studies. On day 7, drug exposures in the dermis were assessed in two ways: (1) dOFM provided the total and unbound drug concentrations in dermal interstitial fluid, and (2) clean punch biopsies after heat separation provided the total concentrations in the upper and lower dermis.ResultsdOFM showed sufficient intra-study precision to distinguish interstitial fluid concentrations between different drugs, dose frequencies and dose strengths, and had good reproducibility between studies. Biopsy concentrations showed much higher and more variable values. Standard dOFM measurements were consistent with values obtained with the recirculation approach.ConclusionsdOFM pig model is a robust and reproducible method to directly determine topical drug concentration in dermal interstitial fluid. Dermal biopsies were a less reliable measure of dermal exposure due to possible contributions from drug bound to tissue and drug associated with skin appendages.

Comparative pharmacokinetic studies of transferosomes loaded gel and pressure sensitive adhesive based patch formulation for transdermal delivery of benztropine mesylate

Oral bioavailability of benztropine mesylate (BZM) is low due to its limited gastric absorption, low biological half-life, and susceptibility to extensive hepatic first pass metabolism. It is an anti-muscarinic drug used for the management of Parkinson's disease. The goal of the present research work was to compare a BZM transferosome-loaded Carbopol 940 gel formulation and an acrylate pressure sensitive adhesive based transdermal patch for their efficacy in transdermal penetration and pharmacokinetic profiles. BZM transferosomes were formulated using the thin-film hydration method. The developed formulation showed a (-) 12.0 mV zeta potential and a mean vesicle size of 138.5 nm. When compared to aqueous BZM solution, transferosomes exhibited a considerable increase in transdermal penetration in an ex vivo study across isolated rat skin. When compared to oral, intravenous, and drug-in-adhesive transdermal patch, in vivo pharmacokinetic investigations in Wistar rats revealed an increase in AUC, Tmax, and MRT and a higher and prolonged drug release from transferosome-loaded gel formulations. The findings suggest that the BZM transferosome-loaded gel might be a better and more patient-friendly alternative to oral administration of BZM for the management of Parkinson's disease.

Dual strategy to improve the oral bioavailability of efavirenz employing nanomicelles and curcumin as a bio-enhancer

The present investigation was focused on the development of Soluplus®-based nanomicelles (NMs) (10 % w/v) loaded with Efavirenz (EFV) (5 mg/mL) and Curcumin (natural bio-enhancer) (CUR) (5, 10 and 15 mg/mL) to improve the oral bioavalability of EFV. Micellar formulations were obtained employing an acetone-diffusion technique. Apparent aqueous solubility was increased up to ∼1250-fold and 25,000-fold for EFV and CUR, respectively. Drug-loaded nanoformulations showed an excellent colloidal stability with unimodal size distribution and PDI values < 0.30. In vitro drug release was 41.5 % (EFV) and 2.6 % (CUR) from EFV-CUR-NMs over 6 h in simulated gastrointestinal fluids. EFV-CUR-loaded NMs resulted as safe nanoformulations according to the in vitro cytocompatibility assays in Caco-2 cells. Furthermore, CUR bio-enhancer activity was demonstrated for those nanoformulations. A CUR concentration of 15 mg/mL produced a significant (p < 0.05) increment (2.64-fold) of relative EFV oral bioavailability. Finally, the active role of the lymphatic system in the absorption process of EFV, after its oral administration was assessed in a comparative pharmacokinetic study in presence and absence of cycloheximide, a lymphatic transport inhibitor.Overall our EFV-CUR-NMs denoted their potential as a novel nanotechnological platform, representing a step towards an optimized “nano-sized” therapy for AIDS patients.

Comparative Pharmacokinetic Study of Rhubarb Anthraquinones in Normal and Nonalcoholic Fatty Liver Disease Rats.

Rhubarb anthraquinones contain five main components, that is, rhein, emodin, aloe-emodin, chrysophanol, and physcion, which demonstrate good therapeutic effects on nonalcoholic fatty liver disease (NAFLD). However, research on its pharmacokinetics in NAFLD remains lacking. This study aimed to investigate the pharmacokinetic differences of rhubarb anthraquinones in normal and NAFLD rats. This study developed an NAFLD rat model by high-fat diet feeding for 6weeks. Normal and NAFLD groups were orally administered different rhubarb anthraquinones doses (37.5, 75, and 150mg/kg). The concentration of the rhein, emodin, aloe-emodin, chrysophanol, and physcion in plasma was determined by high-performance liquid chromatography-ultraviolet. The results revealed significant differences in pharmacokinetic behavior between normal and NAFLD rats. Compared with normal rats, NAFLD rats demonstrated significantly increased maximum plasma concentration (Cmax) and area under the plasma concentration-time curve (AUC0 → ∞) of rhubarb anthraquinones (P<0.05), as well as significantly prolonged time to reach maximum plasma concentration (Tmax), terminal elimination half-life (t1/2), and mean residence time (MRT) of rhubarb anthraquinones (P<0.05). This study indicates significant differences in the pharmacokinetics of rhubarb anthraquinones between the physiological and NAFLD states of rats. Rhubarb anthraquinone demonstrated a longer retention time and slower absorption rate in NAFLD rats and exhibited higher bioavailability and peak concentration. This finding provides important information for guiding the clinical use of rhubarb anthraquinones under pathological conditions.

Intranasal administration of sertraline ensures sustained brain delivery and antidepressant effect in a mouse model of depression

The pursuit of more potent and efficacious antidepressant therapies is of utmost significance. Herein, the intranasal (IN) route was investigated for sertraline brain delivery, encompassing a comparative pharmacokinetic study after a single-dose administration to mice by IN, intravenous (IV) (4.87 mg/kg) and oral (10 mg/kg) routes, and an efficacy/toxicity study to explore the therapeutic effect in mice subjected to the unpredictable chronic mild stress (UCMS) protocol. Neurotransmitters and melatonin were quantified in prefrontal cortex and plasma, respectively. A different drug biodistribution behavior was unveiled for a CNS-acting drug administered by means of the IN route. For the first time, IN administration of sertraline exhibited heightened systemic exposure (bioavailability = 166 %), and a sustained drug release into the brain, in opposition to IV and oral routes, avoiding drug fluctuation. The lower lung exposition (given by normalized area under the curve) observed after IN instillation envisions the reduction of sertraline pulmonary side effects and similarly other peripheral side effects. IN sertraline treatment displayed significant efficacy in ameliorating anhedonia after one week of administration while the 14-day IN treatment regimen translated into decreased immobility time and increased swimming time in the forced swimming test, suggesting an improvement of the depressive-like behavior displayed by the animal depressive-model. Remarkably, these effects were absent with oral sertraline, despite the higher used dose. Noteworthy neurotransmitter alterations were observed, with IN sertraline markedly reducing adrenaline in the prefrontal cortex, while serotonin and melatonin increased following both administration routes. With its sustained brain delivery and serotonin- and melatonin-enhancing potential, the innovative strategy of IN sertraline holds the potential not only to effectively address depressive symptoms but also to mitigate challenges inherent to classic treatments.

Simultaneous determination of four phytoecdysteroids by LC-MS/MS: application to a comparative pharmacokinetic study in normal and adjuvant arthritis rats after oral administration of C. officinalis Kuan phytoecdysteroids extract

C. officinalis Kuan is the dry root of Cyathula officinalis Kuan. Clinically, it is used for fall and flutter injury, rheumatism and arthralgia. Phytoecdysteroids have significant anti-inflammatory effects, and the phytoecdysteroids present in C. officinalis Kuan exhibit potential for treating rheumatoid arthritis. This study first developed a selective, accurate and efficient LC-MS/MS method for 12-day pharmacokinetic studies regarding the simultaneous determination of cyasterone, 25-epi-28-epi-cyasterone, precyasterone and capitasterone from C. officinalis Kuan phytoecdysteroids extract in normal and adjuvant arthritis rats. An Agilent Eclipse Plus C18 RRHD column (1.8 µm, 50mm × 2.1 mm) with a gradient mobile phase consisting of water (A) and acetonitrile (B) was used for analysis. The mass analysis was performed in an Agilent 6430 QQQ-MS mass spectrometer with positive mode multiple reaction monitoring (MRM). The results indicated that the AUC0-t and AUC0-∞ values of the four phytoecdysteroids in adjuvant arthritis rats were different from those in normal rats on the first day, which could provide a helpful reference for pharmacological and toxicological studies, as well as clinical applications of C. officinalis Kuan in the treatment of rheumatoid arthritis.

Comparative Pharmacokinetic Studies of One‐Month Donepezil IM Depot and Once Daily Oral Tablet in Healthy Male Volunteers

AbstractBackgroundThis study is to evaluate the safety and tolerability of single dose of one‐month donepezil IM depot (GB‐5001) in healthy male volunteers and to compare pharmacokinetic parameters of 70mg donepezil IM depot and 10mg once daily oral tablet (Aricept®) in human.MethodIn this phase 1, a randomized, double‐blind, placebo‐controlled, dose‐escalation study, 48 healthy subjects were randomized to single dose of Aricept tablet or placebo or GB‐5001 (70mg or 140mg or 280mg) for 64 days. In this study, safety and tolerability of 70mg donepezil IM depot were examined by monitoring adverse events and vital signs. PK parameters such as AUCt, AUCinf, Cmax and Tmax were compared by measuring donepezil concentration after a single dose of 70mg IM depot and 10mg oral tablet.ResultA single dose of 70mg donepezil IM depot showed no significant adverse events and was well tolerated in healthy male volunteers. In 70mg GB‐5001, all the subjects had measurable concentrations up to 1512 h post dose. The geometric mean of PK exposure parameters are 6482.82 h*ng/mL, 6604.01 h*ng/mL and 11.40 ng/mL for AUCt(0‐1512h), AUCinf, and Cmax, respectively. The median peak concentration (Tmax) was observed at 432h post dose. In 10mg oral Aricept, all the subjects had measurable concentrations up to 240 h post dose. The geometric mean of PK exposure parameters are 656.84 h*ng/mL, 751.34 h*ng/mL and 17.68 ng/mL for AUCt(0‐240h), AUCinf, and Cmax, respectively. The median peak concentration (Tmax) was observed at 2.25 h post dose.ConclusionA single dose of 70mg donepezil IM depot was found to be safe and well tolerated in healthy male volunteers. The pharmacokinetic results of 70mg donepezil IM depot showed stable donepezil blood concentration for more than one month without burst drug release, and showed comparable unit dose drug exposure not lower than that of once daily 10mg oral formulation. Through the PK results for additional higher doses and multiple PK simulations, optimal once monthly dose of donepezil IM depot could be suggested which will be bioequivalent to 10mg once daily tablet.

Study of the pharmacokinetic profile of the medicinal product Gidazepam®, tablets, 50 mg in a bioequivalence study

Aim. The primary aim of this study was to evaluate the pharmacokinetic parameters and confirm the bioequivalence of drugs containing gidazepam, namely Gidazepam® (Valenta Pharm, Russia) and Gidazepam VIC (VIVA Pharm, Republic of Kazakhstan), after a single administration of 1 tablet (50 mg) to healthy volunteers under fasting conditions. The secondary aim was a comparative analysis of safety profiles (adverse events) after a single administration of the studied drugs.Materials and methods. An open, randomized, crossover, two-period comparative study of pharmacokinetics and bioequivalence with adaptive design was conducted in healthy volunteers. Blood sampling was performed 15 minutes before and 20 min, 40 min, 1 h, 2 h, 3 h, 3.5 h, 4 h, 4.5 h, 5 h, 6 h, 8 h, 12 h, 24 h, 48 h, and 72 h after drug administration. High-performance liquid chromatography-tandem mass spectrometry was used for the evaluation of gidazepam and its metabolite (desalkylgidazepam) concentration with the subsequent calculation of pharmacokinetic parameters.Results. From both formulations, gidazepam was quickly absorbed and biotransformed into an active metabolite. Studied drugs had similar pharmacokinetic profiles, as 90% confidence intervals for the ratio of geometric means for Cmax and AUC(0-72) were within the bioequivalence acceptance range of 80.00–125.00 %. No adverse events were recorded as a result of clinical, laboratory or instrument evaluations during the study.Conclusion. Study drugs are considered bioequivalent and show comparable tolerability after a single administration under fasting conditions.

Screening the components in multi-biological samples and the comparative pharmacokinetic study in healthy and depression model rats of Suan-Zao-Ren decoction combined with a network pharmacology

Ethnopharmacological relevanceSuanzaoren Decoction (SZRD) is a classic traditional Chinese prescription, which has been commonly used for treating insomnia, depression and other nerve system diseases for a long time. Aim of this studyThe present study aimed to explore the metabolic profiles in multi-biological samples and pharmacokinetic mechanism between healthy and depression model rats combined with a network pharmacology approach after administration of SZRD. Materials and methodsIn our study, an ultra-high performance liquid chromatography (UPLC)-Q-Exactive Orbitrap Mass Spectrometry method was firstly used to study the prototype components and metabolites of SZRD in plasma, brain, urine, and feces between healthy and depressed rats. The possible metabolic pathways were also speculated. Then a network pharmacological study was conducted on the components in the plasma of model rats. According to the above components screened by network pharmacology and the other reported representative active components, the comparative pharmacokinetic study was established for the simultaneous determination of mangiferin, spinosin, ferulic acid, liquiritin, formononetin. magnoflorine and isoliquiritin between healthy and depression model rats. Finally, molecular docking was used to validate the binding affinity between key potential targets and active components in pharmacokinetics. ResultsA total of 115 components were identified in healthy rats, and 101 components were identified in model rats. The prototype components and metabolites in plasma, brain, urine, and feces were also distinguished. The main metabolic pathways included phase I and phase II metabolic reactions, such as dehydrogenation, oxidation, hydroxylation, gluconaldehyde conjugation, glutathione conjugation and so on. These results provided a basis for the further study of antidepressive pharmacokinetic and pharmacological action in SZRD. Then, according to the degree value of network pharmacological study, it was predicted that 10 components and 10 core targets, which involved in the critical pathways such as neuroactive ligand-receptor interaction, cyclic adenosine monophosphate (cAMP) signaling pathway, serotonergic synapse, phosphatidylinositol-3 kinase (PI3K)-Akt signaling pathway, etc. Finally, the established pharmacokinetic method was successfully applied to compare the pharmacokinetic behavior of these 7 active components in plasma of healthy and depressed rats after oral administration of SZRD. It showed that except magnoflorine, the pharmacokinetic parameters of each component were different between healthy and depressed rats. Molecular docking analysis also indicated that the active compounds in pharmacokinetics could bind tightly to the key targets of network pharmacological study. ConclusionThis study may provide important information for studying the action mechanism of SZRD in treating depression.

Design-of-Experiment-Assisted Fabrication of Biodegradable Polymeric Nanoparticles: In Vitro Characterization, Biological Activity, and In Vivo Assessment.

Berberine (BER) is an alkaloid obtained from berberis plant having broad biological activities including anticancer. BER-encapsulated alginate (ALG)/chitosan (CHS) nanoparticles (BER-ALG/CHS-NPs) were developed for long-acting improved treatment in breast cancer. The surface of the NPs was activated by a conjugation reaction, and thereafter, the BER-ALG/CHS-NP surface was grafted with folic acid (BER-ALG/CHS-NPs-F) for specific targeting in breast cancer. BER-ALG/CHS-NPs-F was optimized by applying the Box-Behnken design using Expert design software. Moreover, formulations are extensively evaluated in vitro for biopharmaceutical performances and tested for cell viability, cellular uptake, and antioxidant activity. The comparative pharmacokinetic study of formulation and free BER was carried out in animals for estimation of bioavailability. The particle size recorded for the diluted sample using a Malvern Zetasizer was 240 ± 5.6 nm. The ζ-potential and the predicted % entrapment efficiency versus (vs) observed were +18 mV and 83.25 ± 2.3% vs 85 ± 3.5%. The high % drug release from the NPs was recorded. The analytical studies executed using infrared spectroscopy, differential scanning calorimetry, and X-ray diffraction expressed safe combinations of the components in the formulation and physical state of the drug revealed to be amorphous in the formulation. Cytotoxicity testing demonstrated that the formulation effectively lowered the cell viability and IC50 of the tested cell line in comparison to a raw drug. The cellular uptake of BER-ALG/CHS-NPs-F was 5.5-fold higher than that of BER-suspension. The antioxidant capacities of BER-ALG/CHS-NPs-F vs BER-suspension by the DPPH assay were measured to be 62.3 ± 2.5% vs 30 ± 6%, indicating good radical scavenging power of folate-conjugated NPs. The developed formulation showed a 4.4-fold improved oral bioavailability compared to BER-suspension. The hemolytic assay intimated <2% destruction of erythrocytes by the developed formulation. The observed experimental characterization results such as cytotoxicity, cellular uptake, antioxidant activity, and improved absorption suggested the effectiveness of BER-ALG/CHS-NPs-F toward breast cancer.

Evaluation of pharmacokinetic parameters of ubiquinol acetate, ubiquinone and ubiquinol in male Sprague-Dawley rats – A comparative study

Objectives: The objective of this study was to evaluate single-dose oral comparative pharmacokinetics studies of ubiquinol acetate (EnQ10), ubiquinone and ubiquinol in male Sprague-Dawley (SD) rats. Materials and Methods: Oral suspension formulations of ubiquinol acetate (EnQ10), ubiquinone, and ubiquinol at 300 mg/kg body weight (equivalent dose of ubiquinone) were prepared in 0.1% (v/v) Tween 80 and 15% (w/v) hydroxypropyl-α-cyclodextrin. Six animals per group for each compound were dosed with oral suspension formulations of EnQ10, ubiquinone, and ubiquinol. Blood samples were collected at time points of 1, 2, 4, 6, 8, 10, 24, 30, and 48 h and plasma samples were analysed using liquid chromatography with tandem mass spectrometry for the analyte’s ubiquinone and ubiquinol. Results: In EnQ10 dosed animals, the plasma mean concentration maximum, Cmax (347.83 ng/mL) of ubiquinol was found to be 2.52 times higher versus ubiquinone dosed animals (137.90 ng/mL). Furthermore, in EnQ10 dosed animals, the observed plasma exposure (AUClast) (4808.94 h*ng/mL) for ubiquinol was found to be 3.96 times higher versus. Ubiquinone dosed animals (1214.42 h*ng/mL). One-way ANOVA (Analysis of Variance) was performed for the Cmax and AUClast of ubiquinol. There was a significant increase (P &lt; 0.05) in the Cmax and AUClast of ubiquinol in animals dosed with EnQ10 compared to the animals dosed with ubiquinone. Conclusion: The findings from this study indicated that ubiquinol acetate (EnQ10) showed better oral bioavailability compared to ubiquinone (CoQ10) when administered orally (300 mg/kg body weight equivalent dose of ubiquinone) in the male in male SD Rats.

Comparative study of the plasma pharmacokinetics and tissue residues of trimethoprim in silky fowls and 817 broilers after single oral administration

A comparative study was performed to investigate the differences in plasma pharmacokinetics (PKs) and tissue residues of trimethoprim (TMP) between silky fowls and 817 broilers. The 2 breeds of chickens received compound sulfadiazine suspension by gavage at 20 mg/kg (measured as TMP). Blood and tissue samples were collected at predetermined time points. The concentrations of TMP in plasma and tissue samples were determined by a validated high-performance liquid chromatography (HPLC) method. The plasma concentration-time data were subjected to noncompartment analysis by WinNonlin program (Pharsight Co., Mountain View, CA). The mean plasma concentrations of TMP in silky fowls were significantly lower than those in 817 broilers at all time-points. Significant differences were also observed between silky fowls and 817 broilers in maximum concentration (Cmax), area under the curve from time 0 to 24 h (AUC0→24 h), apparent volume of distribution (Vd), and total body clearance (ClB). Silky fowls had significantly higher muscle TMP concentrations and longer tissue residual time than 817 broilers. The tissue concentration of TMP followed the order of leg muscle > breast muscle > liver, which was obviously different from that of 817 broilers. The half-lives of TMP in the leg muscle, breast muscle, and liver of silky fowls were 31.42, 10.78, and 0.38 d, respectively. The current withdrawal time (WDT) was not sufficient to prevent violative residues of TMP in the edible tissues of silky fowls, and a WDT much longer than 8 d might be required.

A Comparative Pharmacokinetic Study of Fexuprazan 10 mg: Demonstrating Bioequivalence with the Reference Formulation and Evaluating Steady State.

Fexuprazan is a potassium-competitive acid blocker approved for treating gastric-acid-related diseases. Although the effectiveness of the recent formulation fexuprazan 10 mg has been demonstrated in Phase 3 clinical trials, data on the pharmacokinetics (PKs) of administering fexuprazan 10 mg twice daily at a 12 h interval are lacking. Moreover, it is imperative to ensure the bioequivalence of the new formulation with the previously approved 40 mg formulation. This study evaluated the pharmacokinetics (PKs) of the single- and multiple-dose oral administration of fexuprazan 10 mg tablets in healthy participants (Part 1) and investigated their bioequivalence with 40 mg tablets (Part 2). Part 1 comprised a single- and multiple-dose, one-sequence, two-period design and eight participants, while Part 2 comprised a single-dose, 2 × 2 crossover design and 24 participants. In Part 1, in Periods 1 and 2, participants received single and multiple doses (twice daily) of fexuprazan 10 mg, respectively. The maximum plasma concentration (Cmax) area under the concentration-time curve from 0 to 12 h (AUC0-12h) of the multiple-dose participants was approximately double that of the single-dose participants. In Part 2, the geometric mean ratios (90% confidence intervals) for Cmax and AUC from zero to the time of the last quantifiable concentration (AUClast) of the use of four fexuprazan 10 mg tablets to those of one fexuprazan 40 mg tablet were 1.0290 (0.9352-1.1321) and 1.0290 (0.9476-1.1174), respectively, meeting the bioequivalence criteria. Favorable PKs were observed after single and multiple administrations of one fexuprazan 10 mg tablet, and four fexuprazan 10 mg tablets were pharmacokinetically equivalent to one fexuprazan 40 mg tablet.

ИССЛЕДОВАНИЕ ФАРМАКОКИНЕТИКИ ТВЕРДОДИСПЕРСНОЙ И КРИСТАЛЛИЧЕСКОЙ ФОРМ АНТИВИРУЛЕНТНОГО СРЕДСТВА ФТОРТИАЗИНОН У КРЫС

Prevalent drug resistance of pathogenic bacteria is a major concern for healthcare. Decreased bacterial susceptibility to antibiotics reduces treatment efficiency, putting lives of patients at risk. To overcome this issue, a novel anti-virulence drug Fluorothiazinon (FT) was developed. The drug inhibits type three secretion system and flagella motility of many Gram-negative bacteria. It showed therapeutic activity against a number of pathogenic microorganisms, such as Pseudomonas aeruginosa, Acinetobacter baumannii, Chlamydia trachomatis and Salmonella enterica Typhimurium among others. To find appropriate form for subsequent drug development solid dispersion and crystalline forms of FT were manufactured. In this study we aimed to investigate pharmacokinetics of FT in two forms to find the formulation with higher bioavailability. For comparative pharmacokinetics study rats were allocated to receive a single oral dose 50 mg/kg of the drug in either solid dispersion or crystalline forms. Determination of FT and its metabolite was carried out by high-performance liquid chromatography – tandem mass-spectrometry analysis. Our results show that the solid dispersion form of Fluorothiazinon has a higher oral bioavailability of 235.4% compared to the crystalline form in rats. Therefore, solid dispersion form was demonstrated to be more suitable for dug development to have enhanced bioavailability, leading to increased absorption and possible improved therapeutic potential of the developed drug based on pharmacokinetics data.

Comparative Serum and Brain Pharmacokinetics of Quercetin after Oral and Nasal Administration to Rats as Lyophilized Complexes with β-Cyclodextrin Derivatives and Their Blends with Mannitol/Lecithin Microparticles.

Quercetin (Que) is one of the most studied flavonoids with strong antioxidant properties ascribed to its ability to bind free radicals and inactivate them. However, the low solubility of the compound along with its inadequate absorption after oral administration limit its beneficial effects. Que's complexation with two different cyclodextrin (CD) derivatives (hydroxypropyl-β-CD and methyl-β-CD) via the neutralization/lyophilization method has been found to improve its physicochemical properties. Moreover, blends of the lyophilized powders with mannitol/lecithin microparticles (MLMPs) have been proposed as candidates for intranasal (IN) administration after in vitro and ex vivo evaluations. In this context, a comparative pharmacokinetic (PK) study of the IN vs oral administration of Que lyophilized powders and their blends with MLMPs (75:25 w/w) was performed on Wistar rats. The PK parameters estimated by a non-compartmental analysis using the sparse data methodology in Phoenix® 8.3 (Certara, Princeton, NJ, USA) illustrated the effectiveness of IN administration either in brain targeting or in reaching the bloodstream. Significant levels of the compound were achieved at both sites, compared to those after oral delivery which were negligible. These results favor the potential application of the prepared Que nasal powders for systemic and nose-to-brain delivery for the prevention and/or treatment of neuroinflammatory degenerative conditions, such as Parkinson's and Alzheimer's disease.

A Novel UHPLC-MS/MS-Based Bioanalytical Method Developed for S-Allyl Cysteine in the Establishment of a Comparative Pharmacokinetic Study

A newly UHPLC-MS/MS method development and validation for S-Allyl Cysteine was used to evaluate the comparative pharmacokinetic parameters. SC PLGA NPs (S-Allyl Cysteine Poly (D,L-lactide-co-glycolic acid) Nanoparticles) were developed by the emulsion solvent evaporation method. SC PLGA NPs showed their drug loading and encapsulation efficiency to be 5.13 ± 0.10% and 82.36 ± 4.01%, respectively. SC PLGA NPs showed a spherical morphology of an average size (134.8 ± 4.61 nm), PDI: 0.277 ± 0.004, and −25.3 ± 1.03 mV Zeta-Potential (ZP), and is suitable for oral delivery. The development and validation of the UHPLC-MS/MS bioanalytical method were performed successfully for PK-parameter examinations with 1.219 min RT, MS (162.00/73.10), and a total run-time of 2.0 min. Additionally, 1.0–1000.0 ng/mL was a linear range with inter- and intra-day accuracy of 92.55–99.40%, followed by a precision of 1.88–4.23%. SC PLGA NP’s oral bioavailability was significantly higher (** p &lt; 0.01) in comparison to the SC-S treated groups’ (iv and oral). The antimicrobial activity of SC PLGA NPs proved to be more effective than pure S-Allyl-L-Cysteine with significant results (p &lt; 0.01) in comparison to SC-S. SC PLGA NPs showed fitted physicochemical and enhanced antimicrobial properties, which can be helpful for oral administration. Based on the proposed research results, SC PLGA NPs were used for the improvement in oral bioavailability with a sustained and controlled release of S-Allyl-L-Cysteine delivery.

Simultaneous and dynamic measurement of Schisandrol A changes in rat blood and brain and its comparative pharmacokinetic study in control and Parkinson's disease rats by dual-probe in vivo microdialysis

Schisandrol A (SchA) is the main active ingredient of Schisandra chinensis (Turcz.) Baill., which is a famous traditional Chinese herbal medicine. SchA can penetrate the blood-brain barrier and has a significant neuroprotective effect. A group of multiplexed stable isotope mass tags (MSIMTs, m/z 332, 338, 346, 349, 351, 354, 360, 363, 374 and 377) were synthesized to perform multiplexed stable isotope labeling derivatization (MSILD) of SchA in rat microdialysates and standards. A new magnetic molecularly imprinted polymer was prepared using MSIMT-375-SchA as dummy template. All the 10-plexed derivatives of MSIMTs-SchA can be efficiently and selectively enriched and purified using this adsorbent by magnetic dispersive solid phase extraction (MDSPE) before ultra high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) analysis. It should be pointed out that the MSIMT-346-SchA standard derivative was used as internal standard in the process of MDSPE and UHPLC-MS/MS. On these bases, 9 different rat microdialysate samples can be determined by UHPLC-MS/MS in a single run. The utilization of MSIMTs significantly increased the sensitivity, accuracy, selectivity and analysis throughput. Under the optimized conditions, satisfactory linearity (R2> 0.987), limit of detection (LODs, 0.15–0.26 pg/mL) and lower limit of quantitative (LLOQ, 0.8–2.0 pg/mL) were obtained. Intra- and inter-day precisions were in the range of 2.2% -12.5%, and recoveries 94.2% -106.2%. The matrix effects were very low, and the average derivatization efficiency of 10-plex MSIMTs to SchA was as high as 97.8%. Using the developed dual-probe in vivo microdialysis sampling technique, the proposed analytical method has been applied for comparative pharmacokinetics of SchA in the brain and blood of control and Parkinson's disease (PD) rats.

Comparative pharmacokinetic studies of Ephedra herba in common cold and nephrotic syndrome rat models.

Ephedra herba is a conventional Chinese medicine to treat cold, fever, asthma, edema, and lung diseases in the clinic. At present, most pharmacokinetic studies focus on the pharmacokinetic process of alkaloids in normal animals. However, the non-alkaloid components are also active. In addition, the pharmacokinetic studies under pathological state make more sense for clarifying the material basis of efficacy. In this study, a sensitive and rapid ultra-high-performance-tandem mass spectrometry method was developed and applied to determine nine bioactive components (ephedrine, pseudoephedrine, methylephedrine, (+)-catechin, epicatechin, vitexin, vicenin-2, cinnamic acid, and ferulic acid) in normal, common cold and nephrotic syndrome rats after the oral administration of Ephedra herba. Compared to the normal group, except for ferulic acid, the exposure levels of the other eight components were significantly increased and the plasma clearance clearly declined in common cold rats. Similarly, the exposure levels of seven components other than cinnamic acid and ferulic acid were also significantly augmented and the plasma clearance decreased significantly in nephrotic syndrome rats. In brief, the pathological conditions of the common cold and nephrotic syndrome could lead to alterations in the pharmacokinetics profiles of the nine components, which provide a reference for further exploration of the pharmacodynamics basis of Ephedra herba.

Comparative Pharmacokinetic Study of 5 Active Ingredients after Oral Administration of Zuogui Pill in Osteoporotic Rats with Different Syndrome Types.

Zuogui Pill is a kidney-yin-tonifying formula in traditional Chinese medicine that is widely used to manage osteoporosis with kidney-yin-deficiency in China. Herein, an efficient and accurate high-performance liquid chromatography-tandem mass spectrometry method was developed to determine the concentrations of 5 bioactive compounds in rat plasma following oral administration of Zuogui Pill. Because drug absorption and distribution differ under physiological and pathological conditions, the established method was used to quantify blood components and dynamic change in osteoporotic rats with different syndrome types. Moreover, integrated pharmacokinetic study was conducted to describe the overall pharmacokinetic characteristics of traditional Chinese medicine. The results showed that the absorption, distribution, and metabolism of Zuogui Pill varied widely under different states. The bioavailability of most active components showed significant advantages in osteoporotic rats with kidney-yin-deficiency, which corresponds to the opinion that Zuogui Pill has the effect of nourishing kidney-yin. It is hoped that this finding could interpret the pharmacodynamic substances and mechanism of Zuogui Pill in the treatment of osteoporosis with kidney-yin-deficiency.