Test Drug Research Articles

Perceptions and acceptability of the controlled human malaria infection (CHMI) model in The Gambia: a qualitative study

Controlled human malaria infection (CHMI) studies, i.e. the deliberate infection of healthy volunteers with malaria parasites to study immune response and/or test drug or vaccine efficacy, are increasingly being conducted in malaria endemic countries, including in sub-Saharan Africa. However, there have been few studies on the perceptions and acceptability of CHMI by the local communities. This qualitative study assessed the perception and acceptability of such studies in The Gambia following the first CHMI study conducted in the country in March–May 2018. Data were collected through non-participant observation, in-depth interviews and focus group discussions and analyzed using NVivo 12 software with an inductive-deductive approach. Sixty-seven participants were involved, including volunteers enrolled in the CHMI, community stakeholders and members of the Gambian Ethics Committee. Respondents expressed a positive view about CHMI. Key motivating factors for participation were the financial compensation, comprehensive health checks, and willingness to support malaria research. Risks associated with participation were considered low. Concerns raised included the frequency of bleeding and the blood volume collected.

Method for Testing of Drugs Belonging to Substrates and Inhibitors of the Transporter Protein BCRP on Caco-2 Cells

Introduction. Breast cancer resistance protein (BCRP) is an efflux membrane transporter that controls the pharmacokinetics of a large number of drugs. Its activity may change when taking some endo- and exogenous substances, thus making it a link in drug interactions.Aim. The aim of the study was to develop a method for testing of drugs for belonging to BCRP substrates and inhibitors in vitro.Materials and methods. The work was performed on Caco-2 cells overexpressing BCRP, the cultivation was performed in a transwell-system consisting of the apical and basolateral chambers. Cells were seeded at the bottom of the apical chamber, which is a semipermeable membrane. Primarily, the transport of BCRP substrates: methotrexate, mitoxantrone and quercetin was evaluated in the concentration range of 1, 5, 10, and 50 μM in the direction from the basal chamber to the apical one (Papp b-a) and in the opposite direction (Papp a-b). The ratio Papp b-a / Papp a-b more than «2» characterizes the participation of transporter proteins in the transcellular transport of substances. To confirm the participation of BCRP in their transport the experiment was carried out with the addition of a transporter inhibitor, reserpine, to the transport medium at a concentration of 50 μM. The concentration of substrates in the chambers was analyzed by HPLC-MS/MS.Results and their discussion. The addition of methotrexate (1 μM), mitoxantrone (1 μM), and quercetin (1–10 μM) to both the apical or basolateral chambers of the transwell-system, their content in the recipient chamber was not detected. When methotrexate concentration became 5 μM the Papp b-a / Papp a-b ratio was 3.38 ± 0.08, which indicates the involvement of transporters in its transfer. The addition of methotrexate to the donor chamber at concentrations of 10 and 50 μM, Papp b-a / Papp a-b decreased to values below «2». At mitoxantrone concentration of 5 μM Papp b-a / Papp a-b was 2.72 ± 0.16. An increase in the concentration to 10 μM led to an increase in Papp b-a / Papp a-b to 6.18 ± 0.08. With a substance content of 50 μM the indicator decreased but remained above the value «2». In the quercetin concentration of 50 microns, Papp b-a / Papp was below "2". Reserpine reduced Papp b-a / Papp a-b of methotrexate by 3.31 times (p = 0.0002), which indicates the elimination of asymmetry in the transport of the substance. At a mitoxantrone concentration of 10 microns, reserpine reduced its Papp b-a / Papp a-b by 3.36 times (p < 0.0001). The results indicate the participation of BCRP in the control of the transfer of both substances through the cellular monolayer.Conclusion. A method of testing drugs belonging to BCRP substrates and inhibitors using methotrexate (5 μM) and mitoxantrone (10 μM) as marker substrates and reserpine (50 μM) as inhibitor was developed and tested on Caco-2 cells.

A phase I study comparing the biosimilarity of the pharmacokinetics and safety of recombinant humanized anti-vascular endothelial growth factor monoclonal antibody injection with Avastin® in healthy Chinese male subjects

BackgroundThe biosimilar landscape for malignancies continues to grow, with several biosimilars for reference product bevacizumab currently available. Bevacizumab has been shown to be well tolerated; however, the safety of recombinant humanized anti-vascular endothelial growth factor (VEGF) monoclonal antibody injection remains unclear. This study aimed to compare the pharmacokinetics (PK), safety, and immunogenicity of recombinant humanized anti-VEGF monoclonal antibody injection to that of Avastin® in healthy Chinese male volunteers.MethodsA randomized, double-blind, single-dose, and parallel-group study was performed on 88 healthy men who randomly (1:1) received either the test drug as an intravenous infusion of 3 mg/kg or Avastin®. The primary PK parameter was area under the serum concentration-time curve (AUC) from time zero to last quantifiable concentration (AUC0–t). Secondary endpoints included maximum observed serum concentration (Cmax), AUC from 0 extrapolated to infinity (AUCinf), safety, and immunogenicity. Serum bevacizumab concentrations were measured using a validated enzyme-linked immunosorbent assay (ELISA).ResultsThe baseline characteristics were similar among the two groups. The 90% confidence interval (CI) for the geometric mean ratio of AUC0–t, Cmax and AUCinf between the test group and reference group were 91.71%–103.18%, 95.72%–107.49% and 91.03%–103.43%, respectively. These values were within the predefined bioequivalence margin of 80.00%–125.00%, demonstrating the biosimilarity of the test drug and Avastin®. Eighty-one treatment-emergent adverse events were reported, with a comparable incidence among the test group (90.91%) and the reference group (93.18%). No serious adverse events were reported. The incidence of ADA antibodies in the two groups was low and similar.ConclusionIn healthy Chinese men, PK similarity of recombinant humanized anti-VEGF monoclonal antibody injection to Avastin® was confirmed, with comparable safety and immunogenicity. Subsequent studies should investigate recombinant humanized anti-VEGF monoclonal antibody injection in patients setting.Trial registrationRegistered 08/10/2019, CTR20191923.

Clinical and pharmacological approaches to personalization of the prescription of oral anticoagulants: clinical cases

Anticoagulants play an important role in reducing complications and mortality associated with thromboembolic disease. For some time, vitamin K antagonists (VKAs) have been the main drugs used for long-term oral anticoagulant therapy, but because of the significant limitations of VKAs over the past decade, pharmacological research has led to the development of new direct acting oral anticoagulants (DOACs). Direct acting oral anticoagulants have a rapid onset of action with peak levels within 2–4 hours and a half-life of about 12 hours, which is much shorter than that of vitamin K antagonists, a more predictable anticoagulant effect, no need for dose selection, routine laboratory monitoring of pharmacodynamic effects, and a lower frequency of clinically significant drug-drug interactions compared with warfarin. But anticoagulants can still cause serious adverse drug reactions (ADRs) in the form of hemorrhagic complications in hospitalized patients, as confirmed in studies. Currently, clinicalpharmacological technologies of personalized medicine such as pharmacogenetic and pharmacokinetic studies are considered as promising approaches to improve the safety of modern pharmacotherapy, allowing the prediction and prevention of various ADRs. In addition, there are emerging studies showing the importance of genetic features of patients in relation to the metabolism of oral anticoagulants, as well as described clinical situations where different gene polymorphisms, could be responsible for changes in the pharmacokinetics of DOACs. This article reviews clinical cases in which pharmacogenetic testing and therapeutic drug monitoring are used to optimize the clinical efficacy and maximum safety of anticoagulant therapy with apixaban and rivaroxaban.

Assembling the Puzzle Pieces. Insights for in Vitro Bone Remodeling.

As a highly dynamic organ, bone changes during throughout a person's life. This process is referred to as 'bone remodeling' and it involves two stages - a well-balanced osteoclastic bone resorption and an osteoblastic bone formation. Under normal physiological conditions bone remodeling is highly regulated that ensures tight coupling between bone formation and resorption, and its disruption results in a bone metabolic disorder, most commonly osteoporosis. Though osteoporosis is one of the most prevalent skeletal ailments that affect women and men aged over 40 of all races and ethnicities, currently there are few, if any safe and effective therapeutic interventions available. Developing state-of-the-art cellular systems for bone remodeling and osteoporosis can provide important insights into the cellular and molecular mechanisms involved in skeletal homeostasis and advise better therapies for patients. This review describes osteoblastogenesis and osteoclastogenesis as two vital processes for producing mature, active bone cells in the context of interactions between cells and the bone matrix. In addition, it considers current approaches in bone tissue engineering, pointing out cell sources, core factors and matrices used in scientific practice for modeling bone diseases and testing drugs. Finally, it focuses on the challenges that bone regenerative medicine is currently facing.

Precipitation of sugammadex with nicardipine and labetalol: A laboratory research.

There is a paucity of clinical data about whether sugammadex forms precipitates with other medications. This laboratory experimental study was performed to determine the drugs that produce precipitates with sugammadex. Samples of 1ml of sugammadex were prepared in transparent cylinders, to which 1ml of test drugs (rocuronium, neostigmine, glycopyrrolate, atropine, nitroglycerin, dobutamine, dopamine, epinephrine, vasopressin, norepinephrine, phenylephrine, ephedrine, esmolol, nicardipine, and labetalol) was added. The precipitation reaction was observed visually and via light microscope. The pH of each drugs before and after mixing with sugammadex was measured. White crystals were formed when sugammadex was mixed with nicardipine or labetalol. Sugammadex formed precipitate when mixed with nicardipine or labetalol. Sufficient fluid flushing is required between injections of each drug to prevent these reactions.

A Bioequivalence Study of Allergostin® Compared to Administration of Kestin® in Healthy Volunteers

Relevance. International non-proprietary name (INN) Ebastin is widely used in medical practice in the treatment of urticaria and allergic rhinitis. It is an antiallergic drug, which belongs to the second generation of H1-histamine receptor blocker, it is necessary to emphasize that Ebastin is effective when taken orally. As part of the registration of trade name Allergostin, a clinical study of its bioequivalence with Kestin was conducted with the participation of 26 healthy volunteers.
 Aim. The aim of this publication is summarize results of the clinical study of the comparative pharmacokinetics and bioequivalence, safety and tolerability of Allergostin, film-coated tablets, 20 mg (NTFF POLYSAN LLC, Russia), and Kestin, film-coated tablets, 20 mg (Almiral S.A., Spain), in healthy volunteers after a single oral dose on an empty stomach.
 Materials and methods. To confirm bioequivalence, an open, randomized, two-period, cross-over study of comparative pharmacokinetics and bioequivalence of drugs with a single oral intake on an empty stomach in adult healthy male and female volunteers was conducted. During the study, blood plasma samples were taken from volunteers. Each sample was tested by using a validated high performance liquid chromatography with tandem mass spectrometry method, the concentrations of ebastine and the active metabolite carabastin were determined. Based on obtained data , pharmacokinetic and statistical analysis was carried out, 90% confidence intervals (CI) were calculated for the ratio of the geometric mean values of the pharmacokinetic parameters Cmax and AUC0-72 for carabastin.
 Results. Based on results of statistical analysis, it was shown that the pharmacokinetic parameters of the test (Allergostin) and reference (Kestin) drug are characterized by high similarity. For the estimated pharmacokinetic parameters of carabastin, 90% CI ranged from 80-125% for AUC0-t and Cmax.
 Conclusion. Thus, according to the applied criteria, the drugs are recognized as bioequivalent.

Multiscale Anisotropic Scaffold Integrating 3D Printing and Electrospinning Techniques as a Heart-on-a-Chip Platform for Evaluating Drug-Induced Cardiotoxicity.

Cardiac safety assessments are significant in drug discovery, as drug-induced cardiotoxicity (DIC) is the primary cause of drug attrition. Despite heart-on-a-chip (HoC) technology becoming an increasingly popular tool for evaluating DIC, its development remains a challenge owing to the anisotropic cardiac structure of the native myocardium. Herein, an anisotropic multiscale cardiac scaffold is presented via a hybrid biofabrication method by combining 3D printing with electrospinning technology, where the 3D-printed micrometer-scale scaffold frames enable mimicking the interwoven myocardium anatomical structure and the branched-aligned electrospun nanofibers network is able to directionally guide cellular arrangements. The in vitro 3D bioengineered cardiac tissues are then fabricated by encapsulating three-layer multiscale scaffolds within a photocurable methacrylated gelatin hydrogel shell. It is demonstrated that such an anisotropic multiscale structure could contribute to enhancing cardiomyocyte maturation and synchronous beating behavior. More attractively, with the integration of 3D bioengineered cardiac tissues and a self-designed microfluidic perfusion system, a 3D anisotropic HoC platform is established for evaluating DIC and cardioprotective efficacy. Collectively, these results indicate that the HoC model developed by integrating the 3D bioengineered cardiac tissues could effectively recapitulate the clinical manifestations, thereby highlighting their efficacy as a valuable preclinical platform for testing drug efficacy and cardiotoxicity.

Assessment of potential pathogenic bacterial load and multidrug resistance in locally manufactured cosmetics commonly used in Dhaka metropolis

In Bangladesh cosmetics are being produced disregarding the Good Manufacturing Practices. So, this study aimed to test the level and nature of bacterial contamination of such cosmetics. A total of 27 cosmetics comprising eight lipsticks, nine powders, and ten creams were bought from New Market and Tejgaon areas of Dhaka city and tested. Bacteria was detected in 85.2% of samples. Majority of the samples (77.8%) exceeded the limit given by the Bangladesh Standards and Testing Institution (BSTI), Food and Drug Administration (FDA) and the International Organization for Standardization (ISO). Both Gram-negative (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Salmonella spp.) and Gram-positive bacteria (species of Streptococcus, Staphylococcus, Bacillus and Listeria monocytogenes) were identified. Hemolysis was observed in 66.7% Gram-positive and 25% Gram-negative bacteria. Multidrug resistance was tested in 165 randomly selected isolates. Every species of Gram-positive and Gram-negative bacteria exhibited varying levels of multidrug resistance. The highest levels of antibiotic resistance were in broad-spectrum antibiotics (ampicillin, azithromycin, cefepime, ciprofloxacin and meropenem) and narrow-spectrum Gram-negative antibiotics (aztreonam and colistin). Multidrug resistance was 12–78% in Gram-negative bacteria and 12–100% in Gram-positive bacteria. Coagulase and DNase were identified in 97.5% and 5.1% of Staphylococcus aureus isolates respectively. Our findings indicate that these cosmetics pose a risk to the public’s health.

Typewriter Tinnitus: Value of ABR as a Diagnostic and Prognostic Indicator.

Typewriter tinnitus refers to a special kind of staccato tinnitus, which is mostly described by patients as Morse code, popcorn, or machine-gun. It has been accepted that the mechanism of typewriter tinnitus is caused by the neurovascular compression of the cochleovestibular nerve. Patients who suffered from typewriter tinnitus have exhibited a good response to carbamazepine or oxcarbazepine, but there is a risk of recurrence after treatment cessation. The present study aims to determine the value of auditory brainstem response (ABR) in diagnosing typewriter tinnitus and predicting relapse after drug withdrawal. Patients who presented with typewriter tinnitus from March 2019 to March 2022 were included for the present retrospective study. The auditory and vestibular test results and drug treatment effects were collected and analyzed. Patients with idiopathic unilateral subjective tinnitus, who were matched by age to patients with typewriter tinnitus at a ratio of 2:1, were consecutively recruited for the control group. Eighteen patients with typewriter tinnitus and 38 controls were included. Ears with typewriter tinnitus had longer interpeak latency (IPL) I-III, and wave III and V latencies, and a higher ratio of IPL I-III ≥2.3 ms based on ABR, when compared to the unaffected side and controls ( p <0.05). Seventeen patients with typewriter tinnitus responded positively to medication. Among these patients, seven patients had a relapse after drug cessation, while 10 patients did not have a relapse. The relapse group had significantly longer IPL I-III and wave V latency, older age, and poorer hearing, when compared to the nonrelapse group ( p < 0.05). Furthermore, IPL I-III had the largest area under the receiver operating characteristic curve, and the optimal cutoff was 2.4 ms (sensitivity, 100.0%; specificity, 66.7%). There were no significant differences in other demography or other clinical test results between the relapse and nonrelapse groups ( p > 0.05). Ramsay Hunt syndrome and neuromyelitis optica spectrum disorders were identified in two cases. Prolonged IPL I-III based on ABR can help in the diagnosis of typewriter tinnitus and its prognosis after treatment cessation. Patients with IPL I-III greater than 2.4 ms, older age and poorer hearing are more likely to relapse. In addition to the neurovascular conflict of the cochleovestibular nerve, the etiologies of neuroinflammation and demyelinating diseases are also possible for typewriter tinnitus.

Development of optimal in vitro release and permeation testing method for rectal suppositories

Currently there are no compendial assays for testing drug release from rectal suppositories. It is therefore essential to study different in vitro release testing (IVRT) and in vitro permeation testing (IVPT) methods for identifying a suitable technique to compare in vitro drug release and to predict in vivo performance of rectal suppositories. In the present study, three different rectal suppository formulations of mesalamine (CANASA, Generic, and In-house) were studied for in vitro bioequivalence. All the different suppository products were characterized by performing weight variation, content uniformity, hardness, melting time, and pH tests. Viscoelastic behavior of the suppositories was also tested both in presence and absence of mucin. Four different IVRT techniques such as Dialysis, Horizontal Ussing Chamber, Vertical Franz cell, and USP apparatus 4. IVPT studies were performed using Horizontal Ussing chamber and Vertical Franz cell methods. Q1/Q2 equivalent products (CANASA, Generic) and a half-strength product were studied to understand the reproducibility, bio relevance, and discriminatory ability of the IVRT and IVPT methods. This study is the first of its kind where molecular docking studies were performed to determine the potential interactions of drug (mesalamine) with mucin, IVRT studies were conducted with and without the presence of mucin, and porcine rectal mucosa was used to perform IVPT tests. The USP 4 method and Horizontal Ussing chamber methods were found to be suitable IVRT and IVPT techniques, respectfully, for rectal suppositories. RLD (Reference Listed Drug) and Generic rectal suppositories were found to exhibit similar release rate and permeation profiles obtained from USP 4, and the IVPT studies, respectfully. Wilcoxon Rank Sum/Mann-Whitney rank test, conducted for the IVRT profiles obtained using USP 4 method, proved the sameness of RLD and Generic suppository products.

A comparison of phenotypic and WGS drug susceptibility testing in Mycobacterium tuberculosis isolates from the Republic of Korea.

WGS has significant potential to help tackle the major public health problem of TB. The Republic of Korea has the third highest rates of TB of all Organisation for Economic Cooperation and Development countries but there has been very limited use of WGS in TB to date. A retrospective comparison of Mycobacterium tuberculosis (MTB) clinical isolates from 2015 to 2017 from two centres in the Republic of Korea using WGS to compare phenotypic drug susceptibility testing (pDST) and WGS drug susceptibility predictions (WGS-DSP). Fifty-seven MTB isolates had DNA extracted and were sequenced using the Illumina HiSeq platform. The WGS analysis was performed using bwa mem, bcftools and IQ-Tree; resistance markers were identified using TB profiler. Phenotypic susceptibilities were carried out at the Supranational TB reference laboratory (Korean Institute of Tuberculosis). For first-line antituberculous drugs concordance for rifampicin, isoniazid, pyrazinamide and ethambutol was 98.25%, 92.98%, 87.72% and 85.96%, respectively. The sensitivity of WGS-DSP compared with pDST for rifampicin, isoniazid, pyrazinamide and ethambutol was 97.30%, 92.11%, 78.95% and 95.65%, respectively. The specificity for these first-line antituberculous drugs was 100%, 94.74%, 92.11% and 79.41%, respectively. The sensitivity and specificity for second-line drugs ranged from 66.67% to 100%, and from 82.98% to 100%, respectively. This study confirms the potential role for WGS in drug susceptibility prediction, which would reduce turnaround times. However, further larger studies are needed to ensure current databases of drug resistance mutations are reflective of the TB present in the Republic of Korea.

Comparative pharmacokinetics of two formulations of 2.5-mg rivaroxaban in healthy Korean subjects.

Rivaroxaban is a direct factor Xa inhibitor used for the prevention and treatment of thromboembolic disorders. The objective of this study was to compare the pharmacokinetic profiles of two rivaroxaban formulations after a single dose of rivaroxaban (2.5-mg tablet) in healthy Korean subjects. This study was a randomized, open-label, single-dose, two-period, crossover study that included 34 healthy adult subjects under fasting conditions. The test drug (Yuhan rivaroxaban tablet) or reference drug (Xarelto tablet) was administered in each period. Serial blood samples were collected up to 36 hours post-dose. Plasma concentrations were measured by LC-MS/MS. Pharmacokinetic parameters, including maximum plasma concentration (Cmax) and area under the plasma concentration-time curve from time zero to the last measurable concentration (AUCt), were determined by non-compartmental analysis. The 90% confidence intervals (CIs) for the ratio of the geometric means of Cmax and AUCt for the test drug/reference drug were calculated to evaluate pharmacokinetic equivalence. A total of 28 subjects were included in the pharmacokinetic analysis. The geometric mean ratios (90% CI) of the test drug/reference drug for rivaroxaban were 1.0140 (0.9794-1.0499) for AUCt and 0.9350 (0.8797-0.9939) for Cmax. All adverse events (AEs) were mild, and there was no significant difference in the incidence of AEs between the formulations. The pharmacokinetic parameters of rivaroxaban were compared between the test and reference drug, and both formulations were bioequivalent. The newly developed rivaroxaban tablet is safe and well tolerated as the reference drug (ClinicalTrials.gov identifiers: NCT05418803).

&lt;i&gt;PARP1&lt;/i&gt; GENE KNOCKOUT SUPPRESSES EXPRESSION OF DNA BASE EXCISION REPAIR GENES

The effect of PARP1 knockout in HEK293 cells on the gene expression of DNA base excision repair (BER) proteins was studied. It was shown that the expression of all differentially expressed genes (DEGs) of BER was reduced by knockout. The expression of the DNA glycosylase gene NEIL1, which is considered to be one of the common “hubs” for binding BER proteins, has changed the most. The expression of genes of auxiliary subunits of DNA polymerases δ and ε is also significantly reduced. The PARP1 gene knockout cell line obtained is an adequate cell model for studying the activity of the BER process in the absence of PARP1 and testing drugs aimed at inhibiting repair processes. It has been found for the first time that knockout of the PARP1 gene results in a significant change in the level of expression of proteins responsible for ribosome biogenesis and the functioning of the proteasome.

Evaluation of Antianxiety Effect of Mucuna Pruriens (L) –An Experimental Study in Wistar Albino Rats.

Mucuna Pruriens (MP) is a plant legume growing well in tropical countries like Africa and Asia. Various parts of this plant are used in traditional medicine to treat diseases like Parkinsonism and male infertility and as anabolic agents. These effects are attributed to the biologically active components with antioxidant properties. Many studies are highlighting the antiparkinsonian effect of MP. Twenty-four Wistar albino rats were used in this study to investigate the antianxiety activity. The animals were separated into four groups of six (Control, Diazepam-5mg/kg, MP-200mg/kg, and MP-400/kg). All animals were tested for 18 weeks, with a six-week interval beginning with week one. This study aims to observe the effect of MP on anxiety on the Elevated Plus Maze (EPM). Effects of test drug and control were noted by observing the time spent in the Open &amp; Closed arm of EPM and the number of entries into the open &amp; closed arm and compared among the four groups. Observations were analyzed using One-way ANOVA &amp; Dennett's multiple comparisons tests. Animals treated with Mucuna Pruriens (200, 400mg/kg) produced a significantly increased number of entries and time spent in the open arm in the EPM (p&lt;0.0001) compared with the control group. Mucuna Pruriens, used in this study at doses of 200mg/kg &amp; 400mg/kg, shows an antianxiety effect comparable to that of the standard reference drug diazepam. Diazepam appeared to have a soothing effect, and no sedation was observed with MP powder based on the above results in this study.

A CAF-Based Two-Cell Hybrid Co-Culture Model to Test Drug Resistance in Endometrial Cancers.

The management of advanced or recurrent endometrial cancers presents a challenge due to the development of resistance to treatments. The knowledge regarding the role of the tumor microenvironment (TME) in determining the disease's progression and treatment outcome has evolved in recent years. As a TME component, cancer-associated fibroblasts (CAFs) are essential in developing drug-induced resistance in various solid tumors, including endometrial cancers. Hence, an unmet need exists to test the role of endometrial CAF in overcoming the roadblock of resistance in endometrial cancers. We present a novel tumor-TME two-cell ex vivo model to test CAF's role in resisting the anti-tumor drug, paclitaxel. Endometrial CAFs, both NCAFs (tumor-adjacent normal-tissue-derived CAFs) and TCAFs (tumor-tissue-derived CAFs) were validated by their expression markers. Both TCAFs and NCAFs expressed positive markers of CAF, including SMA, FAP, and S100A4, in varying degrees depending on the patients, while they consistently lacked the negative marker of CAF, EpCAM, as tested via flow cytometry and ICC. CAFs expressed TE-7 and immune marker, PD-L1, via ICC. CAFs better resisted the growth inhibitory effect of paclitaxel on endometrial tumor cells in 2D and 3D formats compared to the resistance of the tumoricidal effect of paclitaxel in the absence of CAFs. TCAF resisted the growth inhibitory effect of paclitaxel on endometrial AN3CA and RL-95-2 cells in an HyCC 3D format. Since NCAF similarly resisted the growth inhibitor action of paclitaxel, we tested NCAF and TCAF from the same patient to demonstrate the protective action of NCAF and TCAF in resisting the tumoricidal effect of paclitaxel in AN3CA in both 2D and 3D matrigel formats. Using this hybrid co-culture CAF and tumor cells, we established a patient-specific, laboratory-friendly, cost-effective, and time-sensitive model system to test drug resistance. The model will help test the role of CAFs in developing drug resistance and contribute to understanding tumor cell-CAF dialogue in gynecological cancers and beyond.

Bioequivalence study of generic nirmatrelvir in healthy volunteers

Nirmatrelvir is an antiviral drug that, in combination with ritonavir, is an effective agent for the etiotropic therapy of patients with mild to moderate COVID-19.The aim of the study was to evaluate bioequivalence of the generic drug nirmatrelvir Аrpaxel in combination with ritonavir and the original drug Paxlovid, which is a combination of nirmatrelvir/ritonavir, in a single dose administration to healthy volunteers.Materials and methods. This research was an open-label, randomized, two-period crossover bioequivalence study. It included 2 periods, in each of which the volunteers received either a test drug (nirmatrelvir at the dose of 300 mg) in combination with ritonavir (100 mg), or a reference drug (a combination of nirmatrelvir 300 mg and ritonavir 100 mg), given as a single dose. A wash-out period between each of the administrations was 7 days. The blood sampling to determine the concentration of nirmatrelvir was carried out in the range from 0 to 36 h in each of the study periods. A nirmatrelvir concentration was determined by a validated HPLC-MS/MS method with a lower quantitation limit of 10 ng/mL. Bioequivalence was assessed by comparing 90% confidence intervals (CIs) for the ratio of geometric means of AUC(0–16) and Cmax of the test drug and reference drugs with the established equivalence limits of 80.00–125.00%.Results. In the study were included 68 healthy volunteers, 67 participants of which were included in the bioequivalence population. The pharmacokinetic parameters of the drugs were comparable to each other. The 90% confidence interval for the ratio of the geometric mean of the maximum drug concentration in the blood plasma and the area under the pharmacokinetic curve «concentration-time» from zero to the last blood draw within 36 hours of nirmatrelvir was 87.26–100.83 and 93.27–103.74%, which meets the criteria for assessing bioequivalence. The test drugs were well tolerated by the volunteers. The incidence of adverse events was similar for the test and reference drugs. No serious adverse events were recorded during the entire study.Conclusion. As a result of this study, bioequivalence of the test and reference drugs has been established.

Evaluation of model-based bioequivalence approach for single sample pharmacokinetic studies.

In a traditional pharmacokinetic (PK) bioequivalence (BE) study, a two-way crossover study is conducted, PK parameters (namely the area under the time-concentration curve [AUC] and the maximal concentration [ ]) are obtained by noncompartmental analysis (NCA), and the BE analysis is performed using the two one-sided test (TOST) method. For ophthalmic drugs, however, only one sample of aqueous humor, in one eye, per eye can be obtained in each patient, which precludes the traditional BE analysis. To circumvent this issue, the U.S. Food and Drug Administration (FDA) has proposed an approach coupling NCA with either parametric or nonparametric bootstrap (NCA bootstrap). The model-based TOST (MB-TOST) has previously been proposed and evaluated successfully for various settings of sparse PK BE studies. In this paper, we evaluate, via simulations, MB-TOST in the specific setting of single sample PK BE study and compare its performance to NCA bootstrap. We performed BE study simulations using a published PK model and parameter values and evaluated multiple scenarios, including study design (parallel or crossover), sampling times (5 or 10 spread across the dosing interval), and geometric mean ratio (of 0.8, 0.9, 1, and 1.25). Using the simulated structural PK model, MB-TOST performed similarly to NCA bootstrap for AUC. For , the latter tended to be conservative and less powerful. Our research suggests that MB-TOST may be considered as an alternative BE approach for single sample PK studies, provided that the PK model is correctly specified and the test drug has the same structural model as the reference drug.

Enzyme Cascade with Horseradish Peroxidase Readout for High-Throughput Screening and Engineering of Human Arginase-1

We report an enzyme cascade with horseradish peroxidase-based readout for screening human arginase-1 (hArg1) activity. We combined the four enzymes hArg1, ornithine decarboxylase, putrescine oxidase, and horseradish peroxidase in a reaction cascade that generated colorimetric or fluorescent signals in response to hArg1 activity and used this cascade to assay wild-type and variant hArg1 sequences as soluble enzymes and displayed on the surface of Escherichia coli. We screened a curated 13-member hArg1 library covering mutations that modified the electrostatic environment surrounding catalytic residues D128 and H141, and identified the R21E variant with a 13% enhanced catalytic turnover rate compared to wild type. Our scalable one-pot single-step arginase assay with continuous kinetic readout is amenable to high-throughput screening and directed evolution of arginase libraries and testing drug candidates for arginase inhibition.

Azobisisobutyronitrile loaded on mesoporous silica particles: A new stressor for solid-state oxidative forced degradation studies

A new approach for testing drug sensitivity to autooxidative degradation in the solid state is demonstrated in this work. A novel solid-state form of stressing agent for autooxidation has been proposed, based on azobisisobutyronitrile loaded into mesoporous silica carrier particles. The new solid-state form of the stressing agent was applied in degradation studies of two active pharmaceutical ingredients: bisoprolol and abiraterone acetate. The effectiveness and predictivity of the method were evaluated by comparing impurity profiles with those obtained by traditional stability testing of commercial tablets containing the investigated APIs. The results obtained by the new solid-state stressor were also compared with those obtained by an existing method for testing peroxide oxidative degradation in the solid state using a complex of polyvinylpyrrolidone with hydrogen peroxide. It was found that the new silica particle-based stressor was able to effectively predict which impurities could be formed by autooxidation in tablets and that this new approach is complementary to methods for testing peroxide oxidative degradation known from the literature.