AUC 0-24h Research Articles

Development of novel nanoemulsion of pioglitazone used in the treatment of diabetes and its gel form for the treatment of skin diseases

Pioglitazone (PGL), an antidiabetic drug within the thiazolidinedione class, is utilized in managing type-2-diabetes-mellitus. Additionally, it has been observed to exhibit therapeutic effects on various inflammatory markers. PGL falls under BCS Class II, which is defined by its low water solubility and slow dissolution rate. The dual aim of our study was to optimize an oral as well as topical PGL-loaded nanoemulsion (PGL-NE) in order to enhance their bioavailability orally as well as topically. Using the Box–Behnken Design Expert software, Pioglitazone-loaded nanoemulsions (NanoE1 to NanoE17) were optimized. The ultrasonication method was employed following excipients-screening and the preparation of PTPD. The optimized nanoformulation (NanoE13) was determined based on its particle size (137.7 ± 7.92 nm), %Transmittance (91.07 ± 1.03), and PDI (0.221 ± 0.004). NanoE13 exhibited sustained drug release, adhering to the Korsemeyer-Peppas model. When converted into a gel (PGL-NE-Gel), it enhanced permeation of the skin and topical bioavailability. The results of dermatokinetic demonstrated a significant i.e., p˂0.001 increase in CSkinmax & AUC0–8h in skin treated with the optimized PGL-NE-Gel compared to PGL-NE and conventional PGL gel. After 2 weeks, reductions of 40.06 %, 27.34 %, and 37.45 % were observed for diabetic control, PGL-S, and PGL-NE, respectively. PGL-NE also significantly lowered the levels of blood-glucose i.e., p < 0.05 as compared to the diabetic-control -group throughout the experiment. We successfully developed a novel PGL-NE and PGL-NE-Gel, which enhanced the solubility, skin permeation, and bioavailability of Pioglitazone for both oral and topical applications.

Enhanced oral bioavailability and in vitro evaluation of cannabidiol camel milk-derived exosome formulation in resistant MDA-MB-231 and MDA-MB-468 breast cancer cells

The potential of camel milk-derived exosomes (CMDE) to enhance the bioavailability of Cannabidiol (CBD) was investigated. CBD-CMDE formulation was prepared using an established procedure and its particle size was 138.4 ± 4.37 nm, and CBD entrapment efficiency of 56.56 ± 4.26 %. In-vitro release studies showed release of 78.27 ± 5.37 % and 46.42 ± 4.75 % CBD from CMDE and control CBD formulation respectively in pH 6.8 at 24 hr. The apparent permeability (Papp) of CBD-CMDE was found to be enhanced by 3.95-fold with Papp of 22.9*10-6 ± 0.34 cm/sec as compared to control CBD formulation with Papp of 5.8*10-6 ± 0.65 cm/sec in MDCK cells. CBD-CMDE was found to be more potent than CBD in 2D cytotoxicity assay with IC50 values of 3.6 ± 0.54 µM, 3.88 ± 0.54 µM and 7.53 ± 0.59 µM, 7.53 ± 0.59 µM against Doxorubicin (DOX) resistant MDA-MB-231 and Rapamycin (RM) resistant MDA-MB-468 breast cancer cells respectively. Moreover, 3D spheroids assay results demonstrated CBD-CMDE with IC50 values of 14 ± 0.85 µM, 15 ± 0.07 µM as compared to CBD alone with IC50 values of 25 ± 0.93 µM, 34.7 ± 0.08 µM in MDA-MB-231 DOX RT cells and MDA-MB-468 RM RT cells respectively. In-vivo PK studies showed enhanced bioavailability of CBD from CBD-exosomes with AUC(0-24h) of 1350.56 ± 187.50 h.ng/mL as compared to CBD control formulation with AUC(0-24h) of 351.95 ± 39.10 h.ng/mL with a single oral dose of 12 mg/kg. The data indicate that CMDE significantly improved the oral bioavailability of CBD. Overall, CMDE can be used to enhance the oral absorption of poorly bioavailable APIs.

Exposure to Mycophenolic Acid and Its Clinical Response in an Indian Pediatric Population with Nephrotic Syndrome.

Children with nephrotic syndrome experience many side effects and frequent relapses when treated with steroids and other drugs. Mycophenolic acid (MPA) is one of the effective and least toxic drug for the treatment of nephrotic syndrome. This drug needs to be monitored for maximal efficacy and minimal toxicity. The therapeutic reference range for this drug is not established for the aforementioned patient population of Indian origin. In this observational study, children with nephrotic syndrome on mycophenolate mofetil were followed up for a minimum duration of three months. Following this, their clinical status (relapse/remission) was determined and the mycophenolate exposure was measured for over 12 hours. A total of 34 participants were included, with 17 (50%) in relapse. Median MPA Area under the curve over 12 hours (AUC0-12h) (36.5 µg·h/ml) in the remission group differed significantly compared to that in the relapse group (17.2 µg·h/ml). Higher exposure to MPA AUC0-12h is associated with clinical remission of pediatric nephrotic syndrome.

Liposome-based loading enhances the distribution of nicotinamide riboside chloride into the brain and its neuroprotective effects in cerebral ischemic mice

ObjectiveNicotinamide riboside (NR) is neuroprotective; however, its low permeability through the blood‒brain barrier restricts its therapeutic efficacy in central nervous system diseases. Compared with oral NR administration, liposome-based NR loading is hypothesized to improve its pharmacological properties during cerebral ischemia, especially when administered intravenously. MethodsNR chloride (NRC) was encapsulated in an optimized liposome composition and administered by bolus intravenous injection. This was followed by examination of its pharmacokinetics, organ distribution, and effects on cerebral ischemia in mice. ResultsCompared with conventional NRC solution, the liposome form led to a 2.76-fold higher Cmax and a 5.32-fold higher AUC0–24h in plasma after a bolus injection of 40 mg/kg. In healthy mouse brain, it caused a significant elevation of Cmax (2.93-fold) and AUC0.25–24h (2.68-fold). In cerebral ischemia model mice, NRC liposomes increased the drug concentration at 1 and 6 h post-ischemia, increased tissue NAD+ and ATP levels, reduced infarct volume (by a further decrease of 35.4%), ensured neuronal survival, attenuated glial activation, and significantly improved behavioral recovery compared with conventional NRC treatment. ConclusionLiposome loading enhances the brain distribution and therapeutic effects of NRC, which strengthens its possibility for clinical translation and neurorestoration in stroke.

Demonstrating Bioequivalence for Two Dose Strengths of Niraparib andAbiraterone AcetateDual-Action Tablets Versus Single Agents: Utility of Clinical Study Data Supplemented with Modeling and Simulation.

The combination of niraparib and abiraterone acetate (AA) plus prednisone is under investigation for the treatment of patients with metastatic castration-resistant prostate cancer (mCRPC) and metastatic castration-sensitive prostate cancer (mCSPC). Regular-strength (RS) and lower-strength (LS) dual-action tablets (DATs), comprising niraparib 100 mg/AA 500 mg and niraparib 50 mg/AA 500 mg, respectively, were developed to reduce pill burden and improve patient experience. A bioequivalence (BE)/bioavailability (BA) study was conducted under modified fasting conditions in patients with mCRPC to support approval of the DATs. This open-label randomized BA/BE study (NCT04577833) was conducted at 14 sites in the USA and Europe. The study had a sequential design, including a 21-day screening phase, a pharmacokinetic (PK) assessment phase comprising three periods [namely (1) single-dose with up to 1-week run-in, (2) daily doseon days 1-11, and (3) daily dose ondays 12-22], an extension where both niraparib and AA as single-agent combination (SAC; reference) or AA alone was continued from day 23 until discontinuation, and a 30-day follow-up phase. Patients were randomly assigned in a parallel-group design (four-sequence randomization) to receive a single oral dose of niraparib 100 mg/AA 1000 mg as a LS-DAT or SAC in period 1, and patients continued as randomized into a two-way crossover design during periods 2 and 3 where they received niraparib 200 mg/AA 1000 mg once daily as a RS-DAT or SAC. The design was powered on the basis of crossover assessment of RS-DAT versus SAC. During repeated dosing (periods 2 and 3, and extension phase), all patients also received prednisone/prednisolone 5 mg twice daily. Plasma samples were collected for measurement of niraparib and abiraterone plasma concentrations. Statistical assessment of the RS-DAT and LS-DAT versus SAC was performed on log-transformed pharmacokinetic parameters data from periods 2 and 3 (crossover) and from period 1 (parallel), respectively. Additional paired analyses and model-based bioequivalence assessments were conducted to evaluate the similarity between the LS-DAT and SAC. For the RS-DAT versus SAC, the 90% confidence intervals (CI) of geometric mean ratios (GMR) for maximum concentration at a steady state (Cmax,ss) and area under the plasma concentration-time curve from 0-24 h at a steady state (AUC 0-24h,ss) were respectively 99.18-106.12% and 97.91-104.31% for niraparib and 87.59-106.69 and 86.91-100.23% for abiraterone. For the LS-DAT vs SAC, the 90% CI of GMR for AUC0-72h of niraparib was 80.31-101.12% in primary analysis, the 90% CI of GMR for Cmax,ss and AUC 0-24h,ss of abiraterone was 85.41-118.34% and 86.51-121.64% respectively, and 96.4% of simulated LS-DAT versus SAC BE trials met the BE criteria for both niraparib and abiraterone. The RS-DAT met BE criteria (range 80%-125%) versus SAC based on 90% CI of GMR for Cmax,ss and AUC 0-24h,ss. The LS-DAT was considered BE to SAC on the basis of the niraparib component meeting the BE criteria in the primary analysis for AUC 0-72h; abiraterone meeting the BE criteria in additional paired analyses based on Cmax,ss and AUC 0-24h,ss; and the percentage of simulated LS-DAT versus SAC BE trials meeting the BE criteria for both. NCT04577833.

Atazanavir/Ritonavir Increased Tizoxanide Exposure from Oral Nitazoxanide through Pharmacokinetic Interaction in Healthy Volunteers

Nitazoxanide use is limited by gastrointestinal side effects associated with increasing dose. In this drug repurposing study, we investigated the possibility of enhancing the exposure of its active metabolite, tizoxanide, through pharmacokinetic interaction with atazanavir/ritonavir. In this crossover drug–drug interaction study, 18 healthy participants received a single dose of 1000 mg of nitazoxanide alone and in combination with 300/100 mg atazanavir/ritonavir in period 1 and 2 respectively. On both days, blood samples for intensive pharmacokinetic analyses were collected at 0–12 h post-dose. To explore the utility of dried blood spots (DBS) as an alternative to plasma for tizoxanide quantification, 50 µL of blood from some participants was spotted on DBS cards and correlated with plasma concentrations. Pharmacokinetic parameters were derived by non-compartmental analysis and compared between both periods. Co-administration of nitazoxanide with atazanavir/ritonavir resulted in a significant increase in tizoxanide plasma exposure [GMR (90% CI) of AUC0–12h, Cmax and C12h being 1.872 (1.870–1.875), 2.029 (1.99–2.07) and 3.14 (2.268–4.352), respectively]. DBS concentration (%CV) was 46.3% (5.6%) lower than plasma concentrations, and there was strong correlation (R = 0.95, p &lt; 0.001) between DBS-derived plasma concentration and plasma concentrations. Co-administration with atazanavir/ritonavir enhanced tizoxanide exposure with no report of adverse events in healthy volunteers.

A Pilot Study To Assess the Suitability of Riboflavin As a Surrogate Marker of Breast Cancer Resistance Protein in Healthy Participants.

We recently showed that riboflavin is a selected substrate of breast cancer resistance protein (BCRP) over P-glycoprotein (P-gp) and demonstrated its prediction performance in preclinical drug-drug interaction (DDI) studies. The aim of this study was to investigate the suitability of riboflavin to assess BCRP inhibition in humans. First, we assessed the substrate potential of riboflavin toward other major drug transporters using established transfected cell systems. Riboflavin is a substrate for organic anion transporter (OAT)1, OAT3, and multidrug and toxin extrusion protein (MATE)2-K, with uptake ratios ranging from 2.69 to 11.6, but riboflavin is not a substrate of organic anion-transporting polypeptide (OATP)1B1, OATP1B3, organic cation transporter (OCT)2, and MATE1. The effects of BMS-986371, a potent in vitro inhibitor of BCRP (IC 50 0.40 μM), on the pharmacokinetics of riboflavin, isobutyryl carnitine, and arginine were then examined in healthy male adults (N = 14 or 16) after oral administration of methotrexate (MTX) (7.5 mg) and enteric-coated (EC) sulfasalazine (SSZ) (1000 mg) alone or in combination with BMS-986371 (150 mg). Oral administration of BMS-986371 increased the area under the plasma concentration-time curves (AUCs) of rosuvastatin and immediate-release (IR) SSZ to 1.38- and 1.51-fold, respectively, and significantly increased AUC(0-4h), AUC(0-24h), and C max of riboflavin by 1.25-, 1.14-, and 1.11-fold (P-values of 0.003, 0.009, and 0.025, respectively) compared with the MTX/SSZ EC alone group. In contrast, BMS-986371 did not significantly influence the AUC(0-24h) and C max values of isobutyryl carnitine and arginine (0.96- to 1.07-fold, respectively; P > 0.05). Overall, these data indicate that plasma riboflavin is a promising biomarker of BCRP that may offer a possibility to assess drug candidate as a BCRP modulator in early drug development. SIGNIFICANCE STATEMENT: Endogenous compounds that serve as biomarkers for clinical inhibition of breast cancer resistance protein (BCRP) are not currently available. This study provides the initial evidence that riboflavin is a promising BCRP biomarker in humans. For the first time, the value of leveraging the substrate of BCRP with acceptable prediction performance in clinical studies is shown. Additional clinical investigations with known BCRP inhibitors are needed to fully validate and showcase the utility of this biomarker.

Compatible co-administration of BioThrax® vaccine and ciprofloxacin—Results of a randomized open-label drug-vaccine interaction trial

The recommended treatment for post-exposure prophylaxis (PEP) following known/suspected exposure to Bacillus anthracis involves immunization with anthrax vaccine adsorbed (AVA, i.e., BioThrax® vaccine) and a course of antimicrobial therapy. A drug-vaccine interaction clinical trial was conducted to determine whether this combined treatment might modify antimicrobial exposure or vaccine immunogenicity.A Phase 2, randomized, open-label, multi-center trial involving 154 healthy adult participants was completed to evaluate the effect of AVA immunization (three doses administered subcutaneously (SC) at weeks 0, 2 and 4) on the pharmacokinetics (PK) of ciprofloxacin, as well as the effect of ciprofloxacin administration (500 mg po bid) on the immunogenicity of AVA. PK parameters were derived using noncompartmental analysis of ciprofloxacin serum concentrations. Immunogenicity was assessed using a toxin neutralizing antibody (TNA) assay resulting in 50 % neutralization factor (NF50) values. Safety was assessed via reports of adverse events (AEs), clinically significant changes in laboratory parameters and vital signs, and collection of solicited local and systemic reactogenicity reactions.Statistical analyses of the steady state (SS) and single dose PK parameters Cmax and AUC0-–12h indicated that the AVA PEP regimen did not significantly modify ciprofloxacin exposure. Comparison of the geometric mean TNA NF50 values between participants receiving AVA + ciprofloxacin and those receiving AVA alone showed that the combined treatment was non-inferior to AVA alone. The trial met all prospectively defined success criteria for the primary PK endpoint and for the secondary PK and immunogenicity endpoints. There were no deaths, SAEs or AEs leading to drug discontinuation or study withdrawal during the trial.Overall, concomitant administration of ciprofloxacin and AVA produced no significant changes in the PK profile of ciprofloxacin nor in the immunogenicity of AVA. Furthermore, this trial demonstrated that the co-administration of ciprofloxacin and AVA was well tolerated in healthy adult participants.

Sodium citrate buffer improves pazopanib solubility and absorption in gastric acid-suppressed rat model

Pazopanib exhibits pH-dependent solubility and its absorption depends primarily on the stomach pH. Significant decrease of pazopanib absorption by coadministration with proton pump inhibitors in clinical situation need to be overcome. Thus, the purpose of this study is firstly to investigate the effect of acidic beverages and sodium citrate buffer on the solubility of pazopanib and secondly to examine the effect of sodium citrate buffer on pazopanib absorption in a rat model with esomeprazole-mediated gastric acid suppression.Pazopanib solubility decreased with increasing pH of sodium citrate buffer in vitro. Interestingly, its solubility in some acidic beverages was significantly lower than that in sodium citrate buffer of the same pH. The AUC0–24h of pazopanib administered in tap water to rats treated with esomeprazole (ESP rats) was 66 % lower than that in the control rats treated with saline. However, AUC0–24h was 4.8 times higher in ESP rats that received pazopanib with sodium citrate buffer (pH 2.3) compared to ESP rats that received pazopanib with tap water. Our results indicate that the drug-drug interactions between pazopanib and proton pump inhibitors can be overcome, at least in part, by suspending pazopanib in sodium citrate buffer.

Meltdose Tacrolimus Population Pharmacokinetics and Limited Sampling Strategy Evaluation in Elderly Kidney Transplant Recipients.

Meltdose tacrolimus (Envarsus®) has been marketed as a formulation achieving a more consistent tacrolimus exposure. Due to the narrow therapeutic window of tacrolimus, dose individualization is essential. Relaxation of the upper age limits for kidney transplantations has resulted in larger numbers of elderly patients receiving tacrolimus. However, due to the physiological changes caused by aging, the tacrolimus pharmacokinetics (PK) might be altered. The primary aim was to develop a population PK model in elderly kidney transplant recipients. Secondary aims were the development and evaluation of a limited sampling strategy (LSS) for AUC estimation. A total of 34 kidney transplant recipients aged ≥65 years, starting on meltdose tacrolimus directly after transplantation, were included. An eight-point whole blood AUC0-24h and an abbreviated dried blood spot (DBS) AUC0-24h were obtained. The PK data were analyzed using nonlinear mixed effect modeling methods. The PK data were best described using a two-compartment model, including three transit compartments and a mixture model for oral absorption. The best three-sample LSS was T = 0, 2, 6 h. The best four-sample LSSs were T = 0, 2, 6, 8 h and T = 0, 1, 6, 8 h. The developed population PK model adequately described the tacrolimus PK data in a population of elderly kidney transplant recipients. In addition, the developed population PK model and LSS showed an adequate estimation of tacrolimus exposure, and may therefore be used to aid in tacrolimus dose individualization.

Derivation and Clinical Utility of Safety Targets for Linezolid-Related Adverse Events in Drug-Resistant Tuberculosis Treatment.

Long-term usage of linezolid can result in adverse events such as peripheral neuropathy, anemia and thrombocytopenia. Therapeutic drug monitoring data from 75 drug-resistant tuberculosis patients treated with linezolid were analyzed using a time-to-event (TTE) approach for peripheral neuropathy and anemia and indirect response modelling for thrombocytopenia. Different time-varying linezolid pharmacokinetic exposure indices (AUC0-24h,ss, Cav, Cmax and Cmin) and patient characteristics were investigated as risk factors. A treatment duration shorter than 3 months was considered dropout and was modelled using a TTE approach. An exposure-response relationship between linezolid Cmin and both peripheral neuropathy and anemia was found. The exposure index which best described the development of thrombocytopenia was AUC0-24h. The final TTE dropout model indicated an association between linezolid Cmin and dropout. New safety targets for each adverse event were proposed which can be used for individualized linezolid dosing. According to the model predictions at 6 months of treatment, a Cmin of 0.11 mg/L and 1.4 mg/L should not be exceeded to keep the cumulative probability to develop anemia and peripheral neuropathy below 20%. The AUC0-24h should be below 111 h·mg/L or 270 h·mg/L to prevent thrombocytopenia and severe thrombocytopenia, respectively. A clinical utility assessment showed that the currently recommended dose of 600 mg once daily is safer compared to a 300 mg BID dosing strategy considering all four safety endpoints.

Initial Results of a Phase 1 Dose Escalation Study of LP-168, a Novel Covalent and Non-Covalent Next-Generation Inhibitor of Bruton's Tyrosine Kinase

Introduction: Inhibitors of Bruton's Tyrosine Kinase (BTKi) have been transformative therapies in chronic lymphocytic leukemia (CLL) and other lymphoid malignancies. Despite extended remissions, most patients (pts) will relapse. Covalent BTKi (cBTKi) including ibrutinib, acalabrutinib, and zanubrutinib, share a common resistance mechanism, acquisition of a C481 mutation in BTK. Non-covalent BTKi (ncBTKi) can overcome this, however, second-site mutations, notably T474 gatekeeper and kinase-dead mutations, have been observed. LP-168 is a selective next generation inhibitor of BTK that can bind wild-type and C481-mutated BTK covalently and non-covalently, respectively, with preclinical activity in resistant CLL models (submitted to ASH 2023). This dual activity is hypothesized to allow efficacy against cells with wild-type BTK through covalent activity while preventing expansion of the most common resistance mechanisms through non-covalent activity. Here we describe initial results of a phase 1 study of LP-168, with safety evaluation focusing on DLT evaluable pts, and efficacy evaluation focusing on the cohort of pts with CLL. Methods: NCT04775745 is a multicenter phase 1 dose escalation study of LP-168 monotherapy in pts with relapsed/refractory B-cell malignancies. CLL pts must have received ≥2 prior therapies. Dose escalation was performed using 3+3 design with expansion at multiple doses. Treatment emergent adverse events (TEAEs) were assessed per NCI CTCAE v5.0. Responses were evaluated using iwCLL 2018 criteria. Intra-patient dose escalation was permitted when dose levels cleared safety evaluation. Results: From 16 Sep 2021 to 10 Jul 2023, 43 DLT-evaluable pts were enrolled, including 35 with CLL, at doses from 100-300 mg daily as well as 150 mg twice daily. Data for this abstract were locked 10 Jul 2023. CLL pts received a median of 3 prior therapies, with 94% receiving a prior cBTKi and 11% a ncBTKi. 20 pts had alterations in TP53, 21 pts had C481S BTK mutations, 7 pts had gatekeeper mutations at T474 BTK, and 5 pts had mutation in PLC γ2 (Table). 33 pts have response data with median follow-up of 12.6 months (Figure). Overall response rate (ORR) including all dose levels was 54.5% (18/33)-all were partial response (PR) or partial response with lymphocytosis (PR-L). When evaluating only pts at doses of 200 mg or higher, ORR was 66.7% (10/15). In the subgroup of pts who had received only one prior BTKi including all dose levels, ORR was 77.8% (14/18). In the subgroup of pts with both BTK C481 and T474 mutations at doses of 150mg BID or 300mg QD, ORR was 75% (3/4). At the time of this report, only 5 pts with CLL have discontinued the study for progressive disease. At data lock, 43 DLT evaluable pts (with all histologies) were evaluable for safety. No DLT have been observed, and most AE have been low grade. TEAE seen in &amp;gt;20% of pts included diarrhea, fatigue, arthralgia, headache, constipation, cough, and dizziness; of those, grade 3 or higher AE included fatigue and constipation in 1 pt each. Serious AE were seen in 11 pts, of which 1 led to discontinuation (intracranial hemorrhage in a mantle cell lymphoma pt in complete remission). No DLT was identified at doses up to 300 mg daily and 150 mg twice daily. No atrial fibrillation/flutter has been reported. Hypertension grade 3 or higher was seen in 1 pt, and 1 pt experienced high-grade bleeding (as described). AE frequency did not increase with increasing doses. Pharmacokinetics showed plasma exposure increases dose-dependently. Steady state AUC 24h was between 47.1-94.6 ug/mL*h with limited accumulation. Steady state half-life was between 15.3-21.9 hours at all doses and C max was between 3500 and 5600 ng/mL. BTK occupancy is nearly at 100% at dose levels that were tested, with little variability among pts. Collective review demonstrates optimal Cmax to be achieved at either 200 or 300 mg dosed daily. Conclusions: LP-168 has been well tolerated in this study, with no DLTs identified at doses up to 300 mg daily. Preliminary efficacy was observed in high risk CLL pts, including those treated with one or more BTKi. Considering safety, efficacy, and PK/PD, dose expansion will occur at 200 mg and 300 mg daily following the FDA Project Optimus guidelines to determine the recommended phase 2 dose. A separate cohort will enroll pts with gatekeeper mutations to further explore efficacy. Updated biomarker, safety, and efficacy data will be presented at the meeting.

Area under the curve of tacrolimus using microsampling devices: towards precision medicine in solid organ transplantation?

Therapeutic drug monitoring of tacrolimus using trough concentration (Cmin) is mandatory to ensure drug efficacy and safety in solid organ transplantation. However, Cmin is just a proxy for the area under the curve of drug concentrations (AUC) which is the best pharmacokinetic parameter for exposure evaluation. Some studies suggest that patients may present discrepancies between these two parameters. AUC is now easily available through mini-invasive microsampling approach. The aim of this study is to evaluate the relationship between AUC and Cmin in patients benefiting from a complete pharmacokinetic profile using a microsampling approach. Fifty-one transplant recipients benefited from a complete pharmacokinetic profile using a microsampling approach, and their 24-h AUC were calculated using the trapezoidal method. The correlation with Cmin was then explored. In parallel, we estimated AUC using the sole Cmin and regression equations according to the post-transplantation days and the galenic form. Weak correlations were found between 24-h AUC observed and the corresponding Cmin (R2 = 0.60) and between AUC observed and expected using the sole Cmin (R2 = 0.62). Therapeutic drug monitoring of tacrolimus using Cmin leads to over- or under-estimate drug exposure in 40.3% of patients. Tacrolimus Cmin appears to be an imperfect reflection of drug exposure. Evaluating AUC using a microsampling approach offers a mini-invasive strategy to monitor tacrolimus treatment in transplant recipients.

Omega-3 fatty acid-based self-microemulsifying drug delivery system (SMEDDS) of pioglitazone: Optimization, in vitro and in vivo studies

Pioglitazone (PGL) is an effective insulin sensitizer, however, side effects such as accumulation of subcutaneous fat, edema, and weight gain as well as poor oral bioavailability limit its therapeutic potential for oral delivery. Recent studies have shown that combination of both, PGL and fish oil significantly reduce fasting plasma glucose,improve insulin resistance, and mitigate pioglitazone-induced subcutaneous fat accumulation and weight gain. Nevertheless, developing an effective oral drug delivery system for administration of both medications have not been explored yet. Thus, this study aimed to develop a self-micro emulsifying drug delivery system (SMEDDS) for the simultaneous oral administration of PGL and fish oil. SMEDDS was developed using concentrated fish oil,Tween® 80, and Transcutol HP and optimized by central composite design (CCD). The reconstituted, optimized PGL-SMEDDS exhibited a globule size of 142 nm, a PDI of 0.232, and a zeta potential of −20.9 mV. The in-vitro drug release study of the PGL-SMEDDS showed a first-order model kinetic release and demonstrated remarkable 15-fold enhancement compared to PGL suspension. Additionally, following oral administration in fasting albino Wistar rats, PGL-SMEDDS exhibited 3.4-fold and 1.4-fold enhancements in the AUC0–24h compared to PGL suspension and PGL marketed product. The accelerated stability testing showed that the optimized SMEDDS formulation was stable over a three-month storage period. Taken together, our findings demonstrate that the developed fish oil-based SMEDDS for PGL could serve as effective nanoplatforms for the oral delivery of PGL, warranting future studies to explore its synergistic therapeutic potential in rats.

Toxicokinetics of recombinant human fibroblast growth factor 21 for injection in cynomolgus monkey for 3months.

Introduction: Recombinant human fibroblast growth factor 21 (FGF-21) is a potential therapeutic agent for multiple metabolic diseases. However, little is known about the toxicokinetic characteristics of FGF-21. Methods: In the present study, we investigated the toxicokinetics of FGF-21 delivered via subcutaneous injection in vivo. Twenty cynomolgus monkeys were injected subcutaneously with different doses of FGF-21 for 86days. Serum samples were collected at eight different time points (0, 0.5, 1.5, 3, 5, 8, 12, and 24h) on day 1, 37 and 86 for toxicokinetic analysis. The serum concentrations of FGF-21 were measured using a double sandwich Enzyme-linked immunosorbent assay. Blood samples were collected on day 0, 30, 65, and 87 for blood and blood biochemical tests. Necropsy and pathological analysis were performed on d87 and d116 (after recovery for 29days). Results: The average AUC(0-24h) values of low-dose FGF-21 on d1, d37, and d86 were 5253, 25268, and 60445μgh/L, and the average AUC(0-24h) values of high-dose FGF-21 on d1, d37, and d86 were 19964, 78999, and 1952821μgh/L, respectively. Analysis of the blood and blood biochemical indexes showed that prothrombin time and AST content in the high-dose FGF-21 group increased. However, no significant changes in other blood and blood biochemical indexes were observed. The anatomical and pathological results showed that continuous subcutaneous injection of FGF-21 for 86 days did not affect organ weight, the organ coefficient, and histopathology in cynomolgus monkeys. Discussion: Our results have guiding significance for the preclinical research and clinical use of FGF-21.

Interaction and potential mechanisms between atorvastatin and voriconazole, agents used to treat dyslipidemia and fungal infections.

Purpose: Voriconazole (VOR) is combined with atorvastatin (ATO) to treat fungal infections in patients with dyslipidemia in clinical practice. However, the pharmacokinetic interactions and potential mechanisms between them are unknown. Therefore, this study aimed to investigate the pharmacokinetic interactions and potential mechanisms between ATO and VOR. Patients and methods: We collected plasma samples from three patients using ATO and VOR. Rats were administered either VOR or normal saline for 6days, followed by a single dose of 2mg/kg ATO, and then plasma samples were collected at different time points. The incubation models of human liver microsomes or HepG2 cells were constructed in vitro. A high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) system was developed to determine the concentration of ATO, 2-hydroxy-ATO, 4-hydroxy-ATO, and VOR. Results: In patients, VOR significantly reduced the metabolism of ATO and slowed the formation of 2-hydroxy- and 4-hydroxy-ATO. In rats pretreated with orally administered VOR for 6 days or normal saline given a single dose of 2mg/kg ATO administered orally on Day 6, the t1/2 of ATO was significantly prolonged from 3.61 to 6.43h, and the area under the concentration-time curve (AUC0-24h) values of ATO increased from 53.86 to 176.84h μg.L-1. However, the pharmacokinetic parameters of VOR (20mg/kg) with or without pretreatment with ATO (2mg/kg) only slightly changed. In vitro studies indicated that VOR inhibited the metabolism of ATO and testosterone, and the IC50 values were 45.94 and 49.81μM. However, no significant change in transporter behaviors of ATO was observed when VOR or transporter inhibitors were co-administered. Conclusion: Our study demonstrated that VOR has significant interactions with ATO, probably due to VOR's inhibition of the CYP3A4-mediated metabolism of ATO. Based on the clinical cases and potential interactions, the basic data obtained in our study are expected to help adjust the dose of ATO and promote the design of rational dosage regimens for pharmacotherapy for fungal infections in patients with dyslipidemia.

Designing and evaluation of dermal targeted combinatorial nanostructured lipid carrier gel loaded with curcumin and resveratrol for accelerating cutaneous wound healing

A nanostructured lipid carrier containing combined curcumin (CUR) and resveratrol (RSV) was prepared and tested for its potential to accelerate wound healing through topical administration. Prepared nano lipid carrier (NLC) formulation had a particle size of 132.3 ± 4.54 nm, polydispersity index (PDI) of 0.478, and zeta potential of −16.6 mV. Entrapment efficiency (EE) for CUR and RSV was found to be 94.21 ± 0.28% and 84.61 ± 0.15%, respectively. Drug loading was found to be 8.560 ± 0.948% (for CUR) and 7.602 ± 0.452% (for RSV). NLC formulation was converted to NLC gel by incorporation of Carbopol 934 for enhancing its dermal applicability. Flux and permeability coefficient for CUR and RSV in NLC gel was found to be 22.087 µg/cm2/h, 11.299 µg/cm2/h, and 0.2208, 0.1129, respectively, through goat ear skin and 19.213 µg/cm2/h, 22.66 µg/cm2/h and 0.1921, 0.2266, respectively, through Strat-MTM membrane. Dermatokinetic study revealed significant enhancement in Cskin max and AUC0–12h in skin sample treated with NLC gel in comparison with plain gel. Also, NLC gel showed longer retention time which indicates prolonged drug action at targeted site thus, NLC gel may show better therapeutic efficacy than plain gel.

Development of 3D DLP Printed Sustained Release Ibuprofen Tablets and Their Pharmacokinetic Evaluation in Rats.

The objective of the present study was to develop digital light processing (DLP) 3D printed sustained release ibuprofen (IBU) tablets using 3D DLP printers for evaluation in in vitro release and in vivo pharmacokinetic studies with their in vitro-in vivo correlation. The resin formulation and printing parameters were optimized using quality by design (QbD) approach, and IBU tablets were printed using DLP printers which works at 385 and 405nm wavelengths. Our results demonstrated that formulation consisting of polyethylene glycol diacrylate (PEGDA) 700, water, IBU, and riboflavin printed at 40-s bottom layer exposure time and 30-s exposure time produced tablets using both 385 and 405nm wavelengths. In vitro dissolution studies showed > 70% drug release at the end of 24h when printed at 405nm wavelength with no significant difference between tablets printed at 385nm. In vivo pharmacokinetic evaluation of the optimized 3D printed tablets printed at 405nm at oral dose of 30mg/kg in rats showed sustained release of IBU with significantly (p < 0.05) higher Cmax of 30.12 ± 2.45µg/mL and AUC(0-24h) of 318.97 ± 16.98 (µg/mL × h) compared to marketed IBU tablet (control). In vivo-in vitro correlation studies showed 80% of drug was absorbed in vivo within 3h from the pulverized 3D printed tablet, whereas intact 3D tablet showed sustained release of IBU with > 75% IBU release in 24h in vitro. Overall, IBU tablets fabricated using DLP printing demonstrated sustained release and enhanced systemic absorption with no significant difference in their release profile at different wavelengths.

Dose adjustment not required for contezolid in patients with moderate hepatic impairment based on pharmacokinetic/pharmacodynamic analysis.

Objective: Contezolid is an oxazolidinone antimicrobial agent newly approved for treatment of Gram-positive bacterial infections. It is primarily metabolized by the liver. This study aimed to assess whether it is required to adjust the dose of contezolid in patients with moderate hepatic impairment for clinicians to use the drug more rationally. Methods: A single-center, open-label, parallel-group study was conducted to compare the pharmacokinetic (PK) parameters of contezolid and its metabolite M2 between the patients with moderate hepatic impairment and healthy controls with normal liver function after oral administration of 800mg contezolid tablets. Monte Carlo simulation was performed to calculate the probability of target attainment (PTA) and cumulative fraction of response (CFR) of contezolid based on the PK and pharmacodynamic data. Results: Oral treatment with 800mg contezolid tablets was safe and well tolerated in both the patients with moderate hepatic impairment and healthy controls. Moderate hepatic impairment did not result in substantial difference in the area under the concentration-time curve from 0 to 24h (AUC0-24h, 106.79 vs. 97.07hμg/mL) of contezolid even though lower maximum concentration (Cmax, 19.03 vs. 34.49μg/mL) compared with healthy controls. The mean cumulative amount excreted in urine from 0 to 48h (Ae0-48h) and renal clearance (CLR) of contezolid did not show significant difference between the two groups. Moderate hepatic impairment was associated with lower Cmax, slightly lower AUC and Ae0-48h of M2 compared to the healthy controls. fAUC/MIC was the best PK/PD index to predict the clinical efficacy of contezolid. Monte Carlo simulation results indicated that at the proposed fAUC/MIC target value of 2.3, the dosing regimen of oral contezolid 800mg q12h could achieve satisfactory PTA and CFR (both >90%) for the target pathogen (methicillin-resistant S. aureus, MIC ≤4mg/L) in patients with moderate hepatic impairment. Conclusion: Our preliminary data suggest that dose adjustment is not required for contezolid in patients with moderate hepatic impairment. Clinical Trial Registration: https://chinadrugtrials.org.cn, identifier: CTR20171377.

Spanlastics as a Potential Approach for Enhancing the Nose-To-Brain Delivery of Piperine: In Vitro Prospect and In Vivo Therapeutic Efficacy for the Management of Epilepsy

The present study delineates the preparation of piperine-loaded spanlastics (PIP-SPL) to improve piperine (PIP) solubility, bioavailability, and permeation through nasal mucosa for intranasal delivery. PIP-SPL was formulated using the thin-film hydration method and optimization was performed using Box-Behnken design (BBD). PIP-SPL optimized formulation (PIP-SPLopt) was characterized for polydispersity index (PDI), vesicle size, entrapment efficiency, zeta potential, and in vitro PIP release. For further evaluation, blood-brain distribution study, transmission electron microscopy (TEM), nasal permeation study, and confocal scanning laser microscopy (CLSM) were performed withal. The PIP-SPLopt presented spherical and sealed shape vesicles with a small vesicle size of 152.4 nm, entrapment efficiency of 72.93%, PDI of 0.1118, and in vitro release of 82.32%. The CLSM study unveiled that the developed formulation has greater permeation of PIP across the nasal mucosa in comparison with the PIP suspension. The blood-brain distribution study demonstrated higher Cmax and AUC0-24h of PIP-SPL via the intranasal route in comparison to PIP-SPL via oral administration. The in vivo study revealed that the PIP-SPL has good antiepileptic potential in comparison with the standard diazepam, which was evinced by seizure activity, neuromuscular coordination by rotarod test, biochemical estimation of oxidative stress markers, and histopathological studies. Furthermore, nasal toxicity study confirm that the developed PIP-SPL formulation is safer for intranasal application. The current investigation corroborated that the prepared spanlastic vesicle formulation is a treasured carrier for the PIP intranasal delivery for the management of epilepsy.