Reference Preparation Research Articles

Evaluation of the pharmacological efficiency of the lipid extract from the tunic of the marine hydrobiont Halocynthia aurantium (Pallas, 1774)

It was studied effect of the lipid extract isolated from the tunic of the marine hydrobiont Halocynthia aurantium. It was evaluated its administration during hypothermia, hyperthermia, muscle load and the introduction of hexenal as well as its embryotoxic and teratogenic effects The impact of stress (vertical fixation of rats by the dorsal neck fold) was accompanied by an increase in plasma levels of total lipids, total cholesterol, cholesterol/phospholipid ratios and a decrease in total phospholipids, as well as by a change in the quantitative characteristics of classes of neutral and phospholipid. It was carried out a correction of the developed changes by a lipid extract of ascidia and a commercial reference preparation “Omega-3”. The lipid extract of H. aurantium showed a higher efficiency in restoring the lipid composition of the blood plasma under stress impact compared to the preparation “Omega-3” due to a wider range of neutral and phospholipid classes, polyunsaturated fatty acids of the n-3 and n-6 families. The tunica of ascidian can be used as a raw material for obtaining preparations with stress-protector and lipid-correcting properties.

Bioequivalence study of eltrombopag 75 mg film-coated tablets under fasting conditions during the Covid-19 pandemic in healthy Caucasian male subjects

This study aims to determine the bioequivalence of the reference preparation and the test preparation containing eltrombopag when both were given during the COVID-19 pandemic while fasting. Participants in the research were healthy male Caucasian subjects. One film-coated tablet of the test preparation or one film tablet of the reference preparation, equivalent to 75 mg of eltrombopag, was given to the participants in a randomized order throughout each treatment session. At pre determined blood sampling points, blood samples were taken to determine the pharmacokinetics of eltrombopag. Eltrombopag concentrations in the samples were determined using an LC-MS/MS technique verified using ESI(−). The study results were used to calculate the rate (the maximum plasma concentration, or Cmax) and extent (area under the concentration-time curve of plasma, or AUC(0−72) and AUC(0−t) of eltrombopag absorption from the test preparation and reference preparation. The 90% confidence intervals (CI) of the ln-transformed AUC(0−72), AUC(0−t), and Cmax of eltrombopag met the bioequivalence requirements of 80.00–125.00%. Both trial preparations had a similar and very satisfactory safety profile.

Pharmacokinetics and Bioequivalence of Two Powders of Azithromycin for Suspension: A Nonblinded, Single-Dose, Randomized, Three-Way Crossover Study in Fed and Fasting States Among Healthy Chinese Volunteers.

Azithromycin, a macrolide antibiotic, is commonly used to treat mild-to-moderate bacterial infections. This research aimed to evaluate the pharmacokinetics (PK) properties and bioequivalence (BE) of two azithromycin (EQ 100 mg base/packet) powders for suspension in Chinese healthy participants in fed and fasting conditions. A total of 90 Chinese healthy participants were enrolled in this nonblinded, single-dose, randomized, semireplicate, three-period, three-sequence, crossover study. Of them, 42 and 40 were categorized to the fed and fasting conditions, respectively. The washout period between doses was 21 days. Blood specimens were harvested prior to administering the drug and 194 h following administration. The plasma levels of azithromycin were analyzed using a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) approach. PK parameters were measured using noncompartmental analysis. This research compared BE between the reference and test products using the average bioequivalence (ABE) or reference-scaled average bioequivalence (RSABE) method, considering the within-subject variability (SWR) of the reference preparation. Adverse events (AEs) were monitored to examine safety and tolerability. The RSABE method (SWR ≥ 0.294) was used to determine the BE of maximal plasma concentration (Cmax) in both fed and fasting conditions. In the ABE approach, (SWR < 0.294) was adopted to assess the BE of the area under the plasma concentration-time curve from time zero to the last measurable time point (AUC0-t) and determine the area under the plasma concentration time curve from time zero to time infinity (AUC0-inf). In the fasting condition, the point estimate of the test/reference ratio for Cmax was 1.08, with a 95% upper confidence bound of - 0.05 < 0.00. The geometric mean ratio (GMRs) for AUC0-t and AUC0-inf was 115.21% [90% confidence interval (CI) 107.25-123.27%] and 113.07% (90% CI 105.14-121.61%), respectively. In the fed condition, the point estimate of the test/reference ratio for Cmax was 0.94, with a 95% upper confidence bound of - 0.10 < 0.00. The GMR for AUC0-t and AUC0-inf was 99.51% (90% CI of 91.03-108.78%) and 99.43% (90% CI 91.73-107.78%), respectively. These data all satisfied the BE criteria for drugs with high variability. All AEs were transient and mild, and no severe AEs were observed. Our study indicated that the test and reference products of azithromycin (EQ 100 mg base/packet) powder for suspension were bioequivalent and safe in healthy Chinese participants, irrespective of the feeding condition. CLINICAL TRIAL REGISTRATION (CHINADRUGTRIALS.ORG.CN): CTR20232646, registered on 25 August 2023.

A Bioequivalence Study of Azilsartan in Healthy Chinese Subjects.

Azilsartan is an angiotensin II receptor blocker used for treating adult hypertension. It significantly improves cardiovascular outcomes in patients with high-risk hypertension, heart failure, and diabetic nephropathy. A single-center, randomized, open-label, single-dose, dual-cycle, dual-crossover clinical trial was conducted to evaluate the bioequivalence of azilsartan under fasting and postprandial conditions in 60 Chinese healthy volunteers. Thirty healthy subjects were enrolled in each test group, with random cross-administration for fasting and postprandial tests. The concentration of azilsartan in human plasma was evaluated using liquid chromatography-tandem mass spectrometry after a single oral administration of test and reference preparations, each at a dose of 20mg (1 tablet). Pharmacokinetic parameters were determined using WinNonlin8.2 software, and bioequivalence was evaluated using SAS 9.4 software. The geometric mean ratios and 90% confidence intervals for maximum concentration, area under the plasma concentration-time curve from time 0 to the time of last measurable concentration, and area under the plasma concentration-time curve from time 0 to infinity of the test and reference preparations in the fasting and postprandial test groups were in the range of 80%-125%. The incidence of adverse events in the fasting and postprandial test groups was 30% (9/30) and 33.3% (10/30), respectively. No serious adverse events or unexpected adverse drug reactions were observed. In conclusion, the test and reference preparations of azilsartan tablets demonstrate bioequivalence and good safety in healthy Chinese subjects under fasting and postprandial conditions.

Bioequivalence Analysis of Clindamycin Hydrochloride Capsules in Healthy Chinese Subjects Under Fasted and Fed Conditions.

Clindamycin is a lincosamide antibiotic for the treatment of staphylococcal, streptococcal, and anaerobic bacterial infections. We conducted a single-center, single-dose, 2-preparation, 2-period, 2-sequence, randomized, open-label, 2×2 crossover study to evaluate the pharmacokinetics (PKs) and safety of the test and reference clindamycin hydrochloride capsules in healthy Chinese subjects under both fasted and fed conditions. Forty-eight subjects were enrolled in the study totally, with 24 subjects in each group. All subjects were asked to take a test or reference preparation, under either fasted or fed condition, and their blood samples were collected and assayed by a validated high-performance liquid chromatography-tandem mass spectrometry method. PK parameters including maximum plasma concentration, area under the plasma concentration-time curve from time 0 to the last concentration, and area under the plasma concentration-time curve from time 0 to infinity were estimated with noncompartmental model and analyzed. Results showed that the PK profiles of the 2 preparations were consistent and met the bioequivalence criteria. Food was identified as a factor that had an impact on clindamycin absorption. The safety of clindamycin hydrochloride capsules was satisfactory. This study proved that the 2 clindamycin hydrochloride capsules were bioequivalent in healthy Chinese subjects under both fasted and fed conditions.

Pharmacokinetics and bioequivalence of two formulations of mifepristone tablets in healthy Chinese subjects under fasting conditions: a single-center, open, randomized, single-dose, double-period, two-sequence, crossover trial.

A bioequivalence (BE) study was performed to evaluate the pharmacokinetics, safety, and bioequivalence of two formulations of mifepristone tablets in healthy Chinese volunteers under fasting conditions. A single-center, open, randomized, single-dose, double-period, two-sequence, crossover study in healthy subjects under fasting conditions was performed. The subjects received a single fasting dose of mifepristone (10mg/tablet) during the first and second periods, followed by a 14-day washout period, during which frequent pharmacokinetic (PK) sampling occurred up to 120h. The pharmacokinetic parameters of mifepristone were calculated based on the plasma drug concentration-time profile. Primary endpoints were the BE of major pharmacokinetic parameters (AUC0-t and AUC0-∞) and the maximum observed serum concentration (Cmax). Secondary endpoints were safety parameters. Forty subjects (34 male and 6 female subjects) were randomly assigned to treatment, with 39 completing the two-period study. After the single administration of mifepristone tablets (test preparation vs. reference preparation) under fasting conditions, the geometric mean ratios (GMRs) of Cmax, AUC0-t, and AUC0-∞ were 98.76%, 104.28%, and 104.83%, respectively. The primary metabolites of mifepristone (RU42633 and RU42698),the GMRs of Cmax, AUC0-t, AUC0-∞ were 102.33% and 100.97%, 103.17% and 103.71%, 104.02% and 103.84%, respectively. Similarly, for another metabolite of mifepristone (RU42698), the GMRs of Cmax, AUC0-t, and AUC0-∞ were 100.97%, 103.71%, and 103.84%, respectively. All 90% confidence intervals (CIs) for the test/reference AUC ratio and Cmax ratio were within the acceptable range (80%-125%) for BE, which met the requirements of bioequivalence. No serious adverse events (AEs) occurred, and all AEs were classified as level 1 or 2. The PK parameters of mifepristone and its metabolites (RU42633 and RU42698) were measured using the (GMRs) of AUC0-t, AUC0-∞, and Cmax and were similar between the test and reference drug. The two formulations of mifepristone showed good tolerability and a similar safety profile. chinadrugtrials.org.cn, identifier CTR20182413.

6379 Clonidin does not stimulate copeptin release

Abstract Disclosure: G. Binder: None. K. Weber: None. A. Peter: None. R. Schweizer: None. Background: Copeptin is secreted in isomolar amounts along with arginine vasopressin peptide from the posterior pituitary. Its stability makes it a perfect candidate for a biomarker of AVP deficiency. In children, the infusion of arginine and bolus of insulin stimulate copeptin; the respective stimulation test could be an alternative to the water deprivation test. Here, we retrospectively studied the effect of clonidine on copeptin release. Design and patients: This is a monocentric retrospective analysis of donated residual serum samples from 42 children with suspected of GH deficiency who underwent clonidine stimulation between 2020 and 2023. Measurements: Copeptin was measured in baseline, 30-, 60-, 90- and 120-min samples by BRAHMS Copeptin proAVP Kryptor immunofluorescence assay. GH was measured using an in-house RIA calibrated against the WHO International Reference Preparation 98/574. Results: According to the test results (clonidine and arginine test), there were 20 patients with GHD and 16 without GHD. No patient had polyuria-polydipsia syndrome. Median age was 6.7 years (quartiles; 5.6-7.8), the median height was -2.92 SDS (-3.42- -2.34), and the median BMI was-0.29 SDS (-1,32 - +0,16). The median baseline level of copeptin was 5,6 pmol/l (3.4-9.6). Median copeptin mildly decreased to 4.5 pmol/l (3.0-10.0) after 30 min; this change was not significant (P=0.45). Thereafter, median values remained low at 4.6, 4.6 and 4.6 pmol/l (60, 90 and 120 min). There was no correlation between baseline copeptin levels and the diagnosis of GHD. Conclusion: The clonidine stimulation test does not stimulate copeptin release and is therefore not suitable for the assessment of AVP deficiency in children. Presentation: 6/2/2024

Bioequivalence study of two formulations of afatinib dimaleate tablets in healthy subjects under fasting conditions: A randomized, open-label, single-dose, crossover trial.

To evaluate the bioequivalence of two different afatinib dimaleate formulations in healthy Chinese subjects under fasting conditions and to assess their pharmacokinetic and safety profiles. This randomized, open-label, 2-period, crossover, bioequivalence study included 32 healthy Chinese subjects. The subjects were assigned to receive a single 40-mg dose of generic or brand-named afatinib dimaleate tablet. Blood samples were collected pre-dose and up to 120hours after dosing. Healthy subjects orally took the trial preparation (T) (afatinib maleate tablets developed by Jiangxi Shanxiang Pharmaceutical Co., Ltd., Gan Zhou, China) and the reference preparation (R) (afatinib maleate tablets developed by Boehringer Ingelheim Pharma GmbH & Co., Ingelheim, Germany) under fasting conditions in the appropriate period according to the randomization. We measured the blood concentrations, calculated the pharmacokinetic parameters of the two preparations in the human body, and evaluated whether formulations were bioequivalent. Safety of the preparations in healthy subjects was monitored during the whole trial. Safety assessment was conducted by vital signs, physical examination, laboratory examination, and 12-lead electrocardiogram during the study, i.e., from the time the subject received the test drug to the end of the last visit. Under fasting conditions, the 90% confidence intervals (CIs) of the geometric mean ratios of the test/reference for afatinib dimaleate were 93.34 - 103.92% for AUC0-t, 90.26 - 105.52% for Cmax, and 93.49 - 104.05% for AUC0-∞. The 90% CI for the geometric mean ratios (test/reference) of Cmax, AUC0-t, and AUC0-∞ were within the range of 80.00 - 125.00%, indicating that the test formulation was equivalent to the reference formulation in healthy Chinese subjects under fasting conditions. Both products were similar in terms of safety.

Evaluation of Bioequivalence and Pharmacokinetic Profiles for Topical Desonide Cream Using Chinese Skins

Introduction: Skin-blanching assay has been established as a surrogate method for assessing bioequivalence of topical corticosteroids. This study aimed to apply the skin-blanching assay to evaluate the bioequivalence of a test desonide cream (T) compared with the reference Desonide® (R) using Chinese skins. Additionally, the pharmacokinetics and safety profiles were also assessed. Methods: By detecting the degree of skin blanching under different dose durations in a pilot dose-duration-response study, the area under the observed effect-time curve (AUEC) and half of the maximum effect (ED50) was calculated. Based on this, the skin color of different time points after a dose duration of ED50, D1 (0.5 × ED50), and D2 (2 × ED50) were detected as a pharmacodynamic indicator to compare between test and reference creams. Single-center, single-dose, randomized, open-label, two-cycle crossover pharmacokinetic studies were designed to make sure the exposure of tested formulationswas not higher than that of the reference formulations. Subjects experiencing adverse events (AEs) were monitored and utilized for safety analysis. Results: These studies involved 12 subjects for the dose-duration-response study, 100 subjects for the bioequivalence study, and 12 subjects for the pharmacokinetic study. The results showed that the population ED50 was 0.88 ± 0.45 h; the mean ratio of area under effective curve from 0 to 24 h (AUEC0–24h) of test and reference preparations was 0.95, with a 90% confidence interval as 88.09–101.72%, indicating the bioequivalence of the test formulation and Desonide®. The maximum plasma concentration (Cmax) and area under the concentration time curve from time 0 to the last time point (AUC0–t) of T and R were 20.8 ± 11.5 pg/mL versus 19.7 ± 10.1 pg/mL, respectively, and 451.04 ± 363.65 pgh/mL versus 541.47 ± 581.41 pgh/mL, respectively. The systemic exposure of a single dose of the test cream was not higher than that of the reference preparation. All of the volunteers experienced grade 1 AEs, suggesting that single administration of the test desonide cream is well tolerated in the Chinese healthy population. Conclusions: This study demonstrated the applicability of skin-blanching assay in Chinese skins and established the bioequivalence of test and reference desonide creams.

Determination of DTaP vaccine potency by multiplex immunogenicity testing using electrochemiluminescence

Lot release testing of diphtheria, tetanus and acellular pertussis vaccines traditionally relied on in vivo protection models involving challenge of laboratory animals with toxins. Meanwhile, many labs have switched to serological testing of these vaccines, which is often performed in separate in vivo assays, even if all components were formulated into one vaccine product. Here we describe the results of simultaneous serological potency determination of diphtheria (D), tetanus (T) and acellular pertussis (aP) antigens obtained following immunization of guinea pigs with multicomponent pediatric and booster vaccines from different manufacturers. The 4th World Health Organization (WHO) International Standard (IS) for diphtheria toxoid (No. 07/216) and the 4th WHO IS for tetanus toxoid (No. 08/218) were used as reference preparations. For aP, a pediatric vaccine batch containing the antigens pertussis toxoid, filamentous hemagglutinin, pertactin and fimbriae proteins type 2/3 was established as internal control. Quantification of IgG against D, T and aP antigens in guinea pig sera was performed using a hexaplex electrochemiluminescence immunoassay. We further provide proof-of-concept using experimental vaccine samples lacking or containing reduced amounts of diphtheria toxoid in the presence of full amounts of tetanus and pertussis antigens and alum adjuvant. Importantly, the assay confirmed dose-response relationships for all antigens tested and was able to detect diphtheria out-of-specification batches. The results confirmed the suitability of the protocol for combined serology batch release testing of DTaP combination vaccines as first measure towards implementation of full in vitro testing of DTaP vaccines. This report summarizes the data and the protocol used for validation prior to implementation of this method in routine batch release testing of DTaP vaccines, which led to replacement of in vivo challenge experiments in our laboratory following the 3 R (replace, reduce, refine) principle.

Bioequivalence study of low dose drospirenone/ethinyl estradiol 3 mg/0.03 mg film tablets under fasting conditions in Turkish healthy female subjects.

This bioequivalence research aims to evaluate the relative bioavailability and pharmacokinetic characteristics of ethinyl estradiol and drospirenone in the test preparation in comparison to the reference preparation during fasting conditions. A liquid chromatography method with tandem mass spectrometry was used to determine the concentrations of drospirenone and ethinyl estradiol in plasma. The pharmacokinetic parameters that were analyzed were the maximum plasma concentration (Cmax), time to achieve Cmax (tmax), elimination half life, and area under the concentration time curve of plasma (AUC0-t, AUC0-∞ for ethinyl estradiol, and AUC0-72h for drospirenone). Both the AUC and Cmax parameters were determined to be between 80.00% and 125.00% (90% confidence intervals), which is the acceptable range. Based on the study findings, it was concluded that the test formulation, which includes 3 mg of drospirenone and 0.03 mg of ethinyl estradiol, demonstrated bioequivalence when compared to the reference formulation.

Bioequivalence of Recombinant Human Teriparatide Injection in Healthy Adult Female Subjects in the Fasting State.

A single-center, randomized, open, 2-period, self-crossover, single-dose trial was conducted to evaluate the bioequivalence of the test (T) and reference (R) preparations in healthy adult female subjects under fasting conditions. Seventy-six subjects were enrolled in the study, and subjects were randomly divided into 2 groups at a 1:1 ratio and were administered once per period, with a 4-day washout period. In each period, plasma drug concentrations, blood calcium changes, and antibodies were determined for pharmacokinetics, pharmacodynamics, and immunogenicity analysis, respectively, and adverse events were recorded for safety analysis. The 90% confidence intervals for the geometric mean ratios (T:R) of maximum plasma concentration, area under the plasma concentration-time curve from time 0 to the last measurable concentration, and area under the plasma concentration-time curve from time 0 to infinity were within the predefined bioequivalence criterion of 80%-125%, indicating bioequivalence between the T and R preparations under fasting conditions. Comparable serum calcium levels demonstrated pharmacodynamics similarity, and no differences were found in immunogenicity profiles. Additionally, the incidence of adverse reactions to the T preparation was 18.4% lower than that of the R preparation (31.6%). This study confirmed the bioequivalence of the T and R preparations under fasting conditions, along with comparable immunogenicity profiles and good safety.

Bioequivalence and Safety of Two Formulations of Tofacitinib Citrate Tablets in Healthy Chinese Volunteers under Fasting and Fed Conditions: Randomized, Open-Label, 2-Period, Single-Dose, Crossover Trials

Purpose. To evaluate the bioequivalence of two different tofacitinib citrate tablets formulations among healthy Chinese subjects under fasting and fed conditions and to observe the safety of test preparation and reference preparation in healthy subjects. Method. This randomized, open-label, 2-period, crossover, bioequivalence study included 64 healthy Chinese subjects (fasting: n = 32, fed: n = 32). The subjects were assigned to receive a single 5-mg dose of the test or a reference tofacitinib citrate tablets. Blood samples were collected at predose and up to 24 hours after dosing. Area under the plasma concentration time curve from zero to the last measurable concentration (AUC0-t), the area from time zero to infinite (AUC0-∞), and maximum plasma concentration (Cmax) were used for bioequivalence assessment. Safety assessment was conducted by vital signs, physical examination, laboratory examination, and 12-lead electrocardiogram during the study, from the time the subject receiving the test drug to the end of the last visit. Results. Under fed condition, the 90% CIs of the geometric mean ratios of the test/reference for tofacitinib citrate tablets were 98.40–104.16% for AUC0-t, 89.96–116.70% for Cmax, and 98.50–104.15% for AUC0-∞. Under fasting condition, the 90% CIs of the geometric mean ratios of the test/reference for tofacitinib citrate tablets were 93.65–101.60% for AUC0-t, 90.06–109.15% for Cmax, and 93.88–101.51% for AUC0-∞. There were no serious events. Conclusion. The 90% CI for the geometric mean ratio (test/reference) of Cmax, AUC0-t, and AUC0-∞ were within the range of 80.00%–125.00%, indicating that the test formulation was equivalent to the reference formulation in healthy Chinese subjects under both fasting and fed conditions. They are similar in terms of safety. This trial is registered with CTR20190366.

A crossover study to evaluate the pharmacokinetics and bioequivalence of hydroxychloroquine tablets in healthy Chinese subjects.

Hydroxychloroquine (HCQ) has a high variability and a long half-life in the human body. The purpose of this study was to evaluate the bioequivalence of a generic HCQ tablet (test preparation) versus a brand HCQ tablet (reference preparation) under fasting and fed conditions in a crossover design. This was an open-label, two-period randomized, single-dose, crossover study in 47 healthy Chinese subjects who were sequentially and randomly allocated either to the fed group (high-fat meal; n = 23) or the fasting group (n = 24). Participants in each group were randomized to the two arms to receive either a single 200-mg dose of the test preparation or a 200-mg dose of the reference preparation. The application of the two preparations in each patient was separated by a 28-day washout period, regarded as sufficiently long to avoid significant interference from residual drug in the body. Whole blood samples were collected over 72 hours after drug administration. A total of 23 subjects completed both the fed and the fasting parts of the trial. There were no significant differences in Cmax, AUC0-72h, and T1/2 between the test and reference preparation (p < 0.05). Food had no significant effect on Cmax and T1/2 (p < 0.05), but AUC0-72h values were significantly reduced under fed condition compared to fasting condition (p < 0.05). The 90% confidence intervals (CIs) for the geometric mean ratios (GMRs) of Cmax and AUC0-72h were 0.84 - 1.05 and 0.89 - 0.98 in the fed study, and 0.97 - 1.07 and 0.97 - 1.05 in the fasting study, respectively. The carryover effect due to non-zero blood concentrations resulted in higher AUC0-72h values in the second period for both test and reference formulations and had no effect on the statistical results. No serious adverse events were reported. The investigation demonstrated that the test and reference preparations are bioequivalent and well tolerated under both fasting and fed conditions in healthy Chinese subjects.

Pharmacokinetics of Nitazoxanide Dry Suspensions After Single Oral Doses in Healthy Subjects: Food Effects Evaluation and Bioequivalence Study.

Nitazoxanide (NTZ) is an effective antiparasitic drug with potent antiviral and antimicrobial activity. This randomized, open-label, 2-sequence, 2-period crossover trial was designed to evaluate the bioequivalence (BE) of the NTZ dry suspension in healthy subjects and investigated the effect of food intake on the pharmacokinetic (PK) properties of tizoxanide (an active metabolite of NTZ, TIZ). Sixty healthy Chinese subjects were enrolled and received a single dose of 500mg/25mL of preparations on days 1 and 4 under overnight fasting or fed conditions, respectively. The plasma concentration of TIZ was determined using high-performance liquid chromatography/tandem mass spectrometry. PK parameters were calculated using WinNonlin 8.2 and BE was evaluated using SAS 9.4. The 90% confidence intervals for the geometric mean ratio (test/reference) of maximum concentration (Cmax), the area under the curve from time 0 to the time of the last quantifiable concentration (AUC0-t), and the area under the curve from time 0 to extrapolation to infinity (AUC0-∞) were all within the equivalent interval of 80%-125%, compliant with BE requirements. In comparison with fasting, on taking the reference and test preparations of the NTZ dry suspension after a meal, the AUC0-t increased by 48.9% and 47.3%, respectively, the AUC0-∞ increased by 48.4% and 48.3%, respectively, and the post-meal Tmax was prolonged by 1.8-2hours. Our results demonstrate that the test and reference preparations were bioequivalent. High-fat meals significantly improve the degree of drug absorption and delay the rate of drug absorption.

Synthesis, physico-chemical properties and biological activity of 3-(aminophenyl)propionic and 2-amino-2-phenyl butyric acid hexafluosilicates

It is known that dental caries is a serious problem for the health care systems of most countries of the world, and the search for new effective and safe means of treatment and prevention of caries remains an urgent task of modern pharmaceutical science. At the same time, fluoride preparations remain the most effective and widely used in the modern arsenal of means for fighting caries. In recent years, ammonium hexafluorosilicates have been actively studied as potential caries preventive agents due to some advantages compared to traditional means of fluoride caries therapy. The aim of the work, which continues the earlier research of ammonium hexafluorosilicates with aromatic amino acid cations, is the synthesis, establishment of physicochemical properties and biological activity of 3-(3-aminophenyl)propionic, 3-(4-aminophenyl)propionic, 2-amino-2- phenylbutyric acid hexafluorosilicates as potential caries preventive agents. 3-(3-Aminophenyl)propionic, 3-(4-aminophenyl)propionic, 2-amino-2-phenylbutyric acid hexafluorosilicates (I–III, respectively) were synthesized in near-quantitative yields by reacting methanolic solutions of the corresponding amino acids with excess 45% silicon hydrofluoric acid. The isolated complexes were identified using the methods of elemental analysis, IR, NMR, 19F and mass spectroscopy. The solubility of I–III in water was established, which is 0.11–0.32 mol. %. The researched compounds I–III and reference drugs – NaF and (NH4)2SiF6 – were introduced into gels based on the Na-salt of carboxymethylcellulose, which were applied to the teeth and gums of rats. In an experiment on an experimental caries model, it was established that the caries preventive efficiency (СPE) of NaF, (NH4)2SiF6, I–III is 30.3%, 44.7%, 23.7%, 38.5%, 26.3%, respectively, that is, only the СPE of compound II exceeds the corresponding indicator for the reference preparation NaF by 1.27 times, while the СPE values of compounds I and III are inferior to both reference preparations. All studied fluoride preparations effectively normalize the biochemical indicators of dental pulp and homogenate of the oral mucosa of rats (phosphatase, elastase, urease and lysozyme activities, malondialdehyde level) that were on a cariogenic diet, and hexafluorosilicates in some cases are more effective compared to NaF.

Bioequivalence Study of Tebipenem Pivoxil in Healthy Chinese Adults.

Tebipenem pivoxil (TP) is a carbapenem and is applied against pneumonia, otitis media, and sinusitis. This study compared the pharmacokinetics (PK) and safety of a test (T) preparation and reference (R) preparation of TP in healthy Chinese adults. This study was a single-center, randomized, open, single-dose (fasting/postprandial) oral administration, two-agent, two-sequence, two-cycle, crossover bioequivalence trial. A total of 60 participants were enrolled (24 fasting and 36 postprandial). All participants were randomly assigned to the TR sequence and RT sequence. Subsequently, they switched T sequences or R sequences 7 days later. PK blood samples were collected according to the protocol, plasma TP concentration was determined by liquid chromatography-mass spectrometry, main PK parameters were calculated based on a non-compartment model, and adverse events were recorded during the test. In the feeding arm, the geometric mean ratio of maximum concentration (Cmax) was 89.84% (90% confidence interval 84.33-95.70), the geometric mean ratio of area under the plasma concentration-time curve from time 0 to last time of quantifiable concentration (AUC0-t) was 86.80% (83.62-90.10), and the geometric mean ratio of area under the plasma concentration-time curve from time 0 to infinity time of quantifiable concentration (AUC0-∞) was 86.90% (83.73-90.20), which were within the acceptable range of bioequivalence (80-125%). In the fasting arm, the geometric mean ratio of Cmax was 96.07% (89.62-102.99), the geometric mean ratio of AUC0-t was 93.09% (90.47-95.78), and the geometric mean ratio of AUC0-∞ was 93.09% (90.48-95.77), which was within the acceptable range of bioequivalence (80-125%). Hence, the T preparation and R preparation of TP had bioequivalence in the fasting arm and feeding arm of the clinical trial. In addition, all adverse events were mild, and no severe adverse events were noted. Preparations T and R of TP were bioequivalent in the fasting and postprandial groups in clinical trials, and TP was safe.

Safety, Tolerability, and Pharmacokinetics of Voriconazole for Injection in Two Preparations in Chinese Healthy Adult Volunteers.

Voriconazole is a second-generation, synthetic, triazole antifungal drug based on the structure of fluconazole. We compared the safety, tolerability, and pharmacokinetic characteristics of voriconazole for injection (200mg) manufactured by at a dose of 6mg/kg in Chinese healthy adult volunteers. This was a single-center, randomized, open, 2-preparation, single-dose, 2-period, 2-sequence, crossover bioequivalence clinical trial. Twenty-four eligible, healthy, male, and female volunteers were assigned randomly to one of 2 dose-sequence groups (test-reference group or reference-test group) in a 1:1 block. The voriconazole concentration in plasma was determined by protein precipitation and high-performance liquid chromatography-tandem mass spectrometry. The main PK parameters were calculated on the basis of a noncompartmental model. The ratio of the geometric mean of the maximum plasma drug concentration, area under the plasma concentration-time curve from time 0 to the last time of quantifiable concentration, and area under the plasma concentration-time curve from time 0 to infinity of the test preparation, and the reference preparation was 100.4%, 102%, and 102.2%, respectively. The 90% confidence intervals were between 80% and 125%, indicating that the 2 preparations were bioequivalent. The adverse events experienced by healthy adult volunteers were mild. Both preparations had a good safety profile.

Lipid-correcting and antioxidant effects of the lipid complex from the red marine algae Ahnfeltia tobuchiensis under the conditions of a high-fat diet

The influence of the lipid complex isolated from the thallus of the red marine algaeAhnfeltia tobuchiensis(LCA) on the metabolic parameters of the blood and liver of rats under a high-fat diet was studied. It was shown that the administration of LCA had a pronounced lipid-correcting and antioxidant effect, which was superior to that of the reference preparation “Omega 3-6-9” in terms of its ability to restore lipid metabolism, the ratio of lipoprotein fractions and the indices of the endogenous antioxidant protection system, as so as prevent the development of hepatosis. The lipid-correcting and anti-oxidant effect of LCA is specified by the action of n-3 polyunsaturated fatty acids, in particular eicosapentaenoic acid, which are the part of the structure of phospholipids and glycolipids of marine origin, which make up the main part of the studied lipid complex.

ВЛИЯНИЕ НОВЫХ ПРОИЗВОДНЫХ НИКОТИНОВОЙ КИСЛОТЫ НА ГИППОКАМП КРЫС

Experiments on hippocampal slices in rats showed that new nicotine acid derivatives LKhT 8-20 and LKhT 9-20 at a concentration of 5 mM inhibited orthrodromic population responses in field СА1 by 89  1 % and 84  2 %, respectively; in comparison, mexicor (reference preparation) in equal concentration inhibited these responses by 52  4 %. Effectiveness of LKhT 8-20 and LKhT 9-20 exceeded that of mexicor in 1.7 and 1.6 times, respectively; LKhT 8-20 exceeded LKhT 9-20 in 1.1 times. Also, in the presence of L-glutamate (0.75 М) LKhT 8-20 (5 mМ) inhibited the evoked neuron responses by 95  2 % and LKhT 9-20 (5 mМ) by 86  1 %. Therefore, LKhT 8-20 and LKhT 9-20 inhibit synaptic transmission between Schaffer collaterals and pyramidal neurons in rat's hippocampal field СА1. Both compounds are L-glutamergic by nature which reveals itself by almost complete in LKhT 8-20 and to a less degree (primarily) in LKhT 9-20. It may be deduced that hippocampus has an important role in the central effect of these new compounds.