Importance of screening severe COVID-19 patients for IFN-λ1, IL-6 and anti-S1 IgG levels.

Cytokine storm is an important cause of death in COVID-19 patients. A recent clinical study showed that administration of recombinant interferon lambda 1 (IFN-λ1 or IL-29) may prevent severe COVID-19. On the other hand, IL-6 has been associated as a prognostic marker of worsening for COVID-19 patients. The objective of this study is to screen IFN-λ1, IL-6 and antibody levels in consecutive serum sample sets of COVID-19 patients. A total of 365 serum samples collected from 208 hospitalized COVID-19 patients were analyzed for IFN-λ1 and IL-6 levels as well as SARS-CoV-2 neutralizing antibodies and anti-S1 IgG antibodies. Analyses of serum samples for cytokine levels showed that IFN-λ1 (>8 pg/mL) and IL-6 (>2 pg/mL) were detected in approximately 64% and 21% patients, respectively. A decrement in IFN-λ1 levels and IL-6 levels above 35 pg/mL can be sign of clinical severity and upcoming dead. An increment in IL-6 levels wasn't detected in every COVID-19 patient but a decrement in IL-6 levels was related to clinical improvement. Importantly, the detection of IFN-λ1 level together with an increase in anti-S1 IgG antibody response were observed in clinically improved patients. Screening severe COVID-19 patients for IFN-λ1, IL-6, and anti-S1 IgG antibody levels during their hospital stay especially in intensive care units may be beneficial to monitor the clinical status and management of treatment strategies. Importantly, detection of IFN-λ1 together with protective IgG antibody response can be an indication of clinical improvement in severe COVID-19 patients and these patients may be discharged from the hospital soon.

Thermoreversible Gel Formulation for the Intranasal Delivery of Salmon Calcitonin and Comparison Studies of In Vivo Bioavailability.

Objectives: We developed original thermoreversible (sol-gel) formulations of salmon calcitonin (sCT) for nasal applications. The sol-gel has been compared with commercial intranasal sprays in vitro and in vivo studies. The aim of studying sol-gel form is to arrange the viscosity of formulations for a reversible adequate fluidity at different temperatures. This situation may facilitate the use of drugs as sprays and increase the bioadhesive ability to mucosa. Materials and Methods: Characterization of optimum formulations was studied. Validated analytical assays determined the number of sCT. An approximately equal number of commercial and sol-gel dosages were sprayed into the nostrils of the rabbits. Blood samples were collected from the ear veins of rabbits and determined by enzyme immunoassay plates. These plates were evaluated by Thermo Labsystem Multiscan Spectrum at 450 nm. Thanks to Winnonlin 5.2, pharmacokinetic data were evaluated by a non-compartmental method. Results: The absolute bioavailability of the formulation at pH 4 and the commercial product (CP) was compared by evaluating the primary pharmacokinetic data area under the curve 0→tlast. The absolute bioavailability of the commercial intranasal spray was measured 1.88 based on maximum concentration (Cmax) assessment. Cmax of the sol-gel formulation pH 4 was calculated as 0.99 and the relative bioavailability was obtained 53.3%. Conclusion: In vivo pharmacokinetic data of sol-gel formulation with pH 3 showed significantly higher volume of distribution parameter than the CP (111167>35408). It is thought that the formulation adhered to the nasal mucosa releases sCT slowly and less.

Sodium hyaluronate dry powder inhalation in combination with sodium cromoglycate prepared using optimized spray drying conditions.

Sodium hyaluronate (SHA) is an anti-inflammatory and protective agent against bronchoconstriction, and sodium cromoglicate (SCG) prevents exercise-induced bronchoconstriction and inflammation. Based on the pharmacological properties of both substances, this study aimed to develop a dry powder inhaler (DPI) of SHA alone and in combination with SCG. The target of the study was to develop flowable formulations without any surfactants by using the spray drying method. To obtain respirable SHA and SCG:SHA particles, variables of the spray dryer, such as inlet temperature, atomized air flow, and feed solution, were changed. The particles 1-8 µm in size were produced with high yield by spray drying and increasing the ethanol percentage of the feed solution (60%), which is the most remarkable parameter. After that, physicochemical characterizations were performed. The aerosol performance of DPI formulations prepared using lactose was evaluated using Handihaler® DPI. The fine particle fraction (FPF) was 36% for the SHA formulation, whereas it was 52 and 53% for SCG and SHA, respectively, in the SCG:SHA formulation. Consequently, both particles were produced reproducibly by spray drying, and inhaled SHA and SCG:SHA dry powder formulations were developed due to their high FPF and flowability with lactose.

Permeability of olmesartan medoxomil from lipid based and suspension formulations using an optimized HDM-PAMPA model.

Hexadecane membrane-parallel artificial membrane permeability assay (HDM-PAMPA) is based on an artificial HDM that separates the two compartments (donor and acceptor compartment). This model is used to predict the permeability of drugs in gastrointestinal tract and to simulate the passive absorption. In vivo behavior of the drugs can be estimated with these systems in drug development studies. In our study, we optimized HDM-PAMPA model to determine permeability of olmesartan medoxomil (OM) lipid based drug delivery system (OM-LBDDS). In order to prove that LBDDS formulation facilitates the weak permeability of OM, permeation rates were compared with the OM suspension formula (containing 0.25% v/w carboxymethylcellulose). The experiment was performed on a 96-well MultiScreen® PAMPA filter plate (MAIPN4510). The permeability of olmesartan formulations from the donor to acceptor compartment separated by a HDM membrane were determined by the previous validated HPLC method. We created positive control series without coating HDM to present the LBDDS and suspension formulation permeability from uncoated plates. The effective permeability constant (Pe) was calculated by the formula and improvement of permeability of OM-LBDDS formulation from HDM was confirmed. On the contrary there was no permeation of OM-Suspension in the hexadecane coated plates. As a result, the intestinal permeability of OM-LBDDS was calculated to be at least 100 times more than the suspension. OM-Suspension permeation was only observed in the hexadecane uncoated positive control plates. This was also manifestation of HDM-PAMPA mimicking permeability of intestines because of its lipidic construction.

Preparation, characterization and in vitro evaluation of cisplatin-bound triblock polymeric micelle solution for ovarian cancer treatment.

The main objective of this study was to prepare cisplatin (CDDP) bound triblock polymeric micelle solution which will have a hydrophilic shell not being phagocytosed by mononuclear phagocyte system, and evaluate in vitro behavior for the treatment of ovarian cancer. For this aim, CDDP was bound to polyglutamic acid (PGA) and the triblock polymer was prepared using polyethylene glycol)-polylactide-co-glycolide (PEG-PLGA). CDDP-bound triblock copolymer conjugation was characterized, in vitro release and permeability studies were performed using USP II method and Caco-2 cell lines, respectively. The release of CDDP from CDDP-bound triblock polymeric micelle solution was found 87.3 ± 3.56% at the end of the 24th hour. CDDP bound triblock polymeric micelle solution was detected as biocompatible, and permeable according to in vitro studies. According to the MTT results, the measured cytotoxicity was found to be maximum in CDDP-bound triblock polymeric micelle solution when compared with CDDP solution and conjugate in SKOV-3 and OVCAR-3 cells, whereas annexin V-FITC apoptosis results were found to be maximum in A2780 cells.

Comparison of Pharmacodynamics and Celiac Effects of Olmesartan Medoxomil Formulations by using Olmesartan-induced Celiac-rat-model.

INTRODUCTION: Olmesartan Medoxomil (OM) is an angiotensin receptor blocker and has the adverse effect of celiac like enteropathy which was accepted by the FDA in 2013. This disease is characterized by severe diarrhea, weight loss and enteropathy. Although there are many case reports associated with olmesartan-related enteropathy in humans, it has not been described in a long-term animal model study so far. AIM: We developed a self-microemulsifying drug delivery system (OM-SMEDDS) in our previous study to reduce this side effect of the drug and to enhance bioavailability. METHODS: In this study, an artificial hypertension model was established with a dose of 185 µmol /kg L-NAME (N ω-nitro-L-arginine methyl ester) twice in a day intraperitoneally in Wistar albino rats. To determine and compare side effects, the OM-Suspension and OM-SMEDDS were administered at 1.3 mg/kg therapeutic dose during one-month period to the rats. RESULTS: Tension of rats was recorded by measuring from their tails with non invasive blood pressure system. We observed celiac like enteropathy findings like villous atrophy and intraepithelial lymphocytosis and clinical changes like weight loss and severe diarrhea after the treatment with OM-Suspension during one-month experiment. It was also observed that the antihypertensive efficacy of the OM-SMEDDS formulation was higher than the suspension during the experiment, which did not cause enteropathy, diarrhea and weight loss by reducing intestinal exposure. CONCLUSION: Hereby, we evaluated the side effects of two different pharmaceutical forms by designing a sustainable and reproducible celiac rat model that can be induced with olmesartan medoxomil.

Visualisation of real-time oral biodistribution of fluorescent labeled self-microemulsifying drug delivery system of olmesartan medoxomil using optical imaging method.

In the present study, the biodistribution of self-microemulsifying drug delivery system of hydrophobic olmesartan medoxomil (OM-SMEDDS) was determined by labeling with a fluorescent dye VivoTag®680 XL and Xenolight® DiR. Labeled OM-SMEDDS and control dye solution administered orally to mice; real-time dynamic biodistributions over 7 h were determined by 2D-fluorescent imaging to verify their anatomic location. Fluorescent Emissions by Vivotag 680® XL and Xenolight® DiR labeled OM-SMEDDS emitted 2 to 24 times stronger emission than control dye administered group. To further confirm the results, organs were removed and examined using the same technique at the end of 7 h. VivoTag®680XL and Xenolight® DiR emitted 4 and 1.7 times stronger emission respectively than control dye administered mice in ex-vivo organ imaging studies. This study showed that OM-SMEDDS can be succesfully labeled with fluorescent dye and tracked with optical imaging method for the visualisation of biodistribution of drugs and is also useful for enhanced bioavailability.

Synthesis, molecular modeling, in vivo study and anticancer activity against prostate cancer of (+) (S)-naproxen derivatives.

In this study, (S)-naproxen thiosemicarbazides (3a-d), 1,2,4-triazoles (4a-c), triazole-thioether hybride compounds (5a-p) were synthesized and their structures (3a, 3d, 4a and 5a-p) were confirmed by FT-IR, 1H NMR,13C NMR, HR-Mass spectra and elemental analysis. These compounds are designed to inhibit methionine amino peptidase-2 (MetAP2) enzyme in prostate cancer. These compounds (3d, 5a-p) evaluated against androgen-independent prostate adenocarcinoma (PC-3, DU-145) and androgen-dependent prostate adenocarcinoma (LNCaP) cell lines by using MTS method. Compounds 5a, 5b, 5d and 5e showed 14.2, 5.8, 10.8 and 8.4 µM anticancer activity against PC-3 cell lines, compounds 5e, 5g and 5n presented anticancer activity against DU-145 cell lines 18.8, 12.25 and 10.2 µM, and compounds 5g, 5m and 5n exhibited anticancer activity against LNCaP cell lines 12.25, 22.76 and 2.21 µM, respectively. Consequently, of these results, compounds 5e and 5n showed the highest activities against androgen dependent and independent prostate cancer cell lines, so these compounds could be potent small molecules against prostate cancer. Furthermore, mitogen-activated protein kinase (MAPK) pathway activation, AKT (protein kinase B) phosphorylation and androgen receptor activation of compound 5n (SGK636) were investigated in LNCaP cells by using Western blot method. Compound 5n (SGK636) was also tested against mRNA expression analysis of the Bax, Bcl-2, Caspase 3, Caspase 9 by using real-time PCR analysis. Compound 5n was given to nude male mice with cancer in comparison to the control group. Compound 5n was found to reverse the malignant phenotype in the nude male mice, whereas the prostate cancer progressed in the control group. Analysis of some blood parameters in the study showed that they were within the normal values with respect to the control. The blood values of the animals treated according to the control group also exhibited compliance with the blood limit values. Molecular docking and dynamics simulation of compound 5n binding to Methionine Aminopeptidase 2 (MetAP2) enzyme rationalized its potential activity. In addition, inhibition assay MetAP2 enzyme of compound 5n was evaluated. Taken together, we suggest compound 5n to be a potential candidate for prostate cancer therapy.

Synthesis, molecular modeling, in vivo study, and anticancer activity of 1,2,4-triazole containing hydrazide-hydrazones derived from (S)-naproxen.

A new series of 1,2,4-triazole containing hydrazide-hydrazones derived from (S)-naproxen ( 7a-m) was synthesized in this study. The structures of these compounds were characterized by spectral (Fourier-transform infrared spectroscopy, 1 H-nuclear magnetic resonance (NMR), 13 C-NMR, and high-resolution electron ionization mass spectrometry) methods. Furthermore, molecular modeling of these compounds was studied on human methionine aminopeptidase-2. All synthesized compounds were screened for anticancer activity against three prostate cancer cell lines (PC3, DU-145, and LNCaP) using the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium colorimetric method. Compound 7a showed the best activity against the PC3, DU-145 and LNCaP cancer cell lines with IC50 values of 26.0, 34.5, and 48.8 µM, respectively. Compounds 7b, 7k, and 7m showed anticancer activity against cancer cell lines PC3 and DU-145 with IC50 values of 43.0, 36.5, 29.3 µM and 49.8, 49.1, 31.6 µM, respectively. Compounds 7f and 7g showed anticancer activity against PC3 cells with IC50 values of 43.4 and 34.5 µM, respectively. To assess the biodistribution in mice of IRDye800, dye-labeled compound 7a or 100 µM of free dye was injected intravenously into the mice's tail. In vivo images were taken with in vivo imaging system spectrum device at 60, 120, 180, 240, 300, and 360 min after injection. At the end of 360 min, ex vivo studies were carried out to determine in which organs the dye was accumulated in the urogenital system. Ex vivo studies showed that the accumulation of compound 7a in the prostate is greater than that of the free dye, and it is concluded that compound 7a may be promising for the treatment of prostate cancer.

Design and development of a self-microemulsifying drug delivery system of olmesartan medoxomil for enhanced bioavailability.

Olmesartan medoxomil (OM) is a hydrophobic antihypertensive drug with low bioavailability (26%) and is known to have adverse effects such as celiac disease and enteropathy. The purpose of this study was to develop SMEDDS to increase bioavailability and decrease potential side effects of OM. Hydrophilic lipophilic balance was calculated by testing solubility of OM in different oils, surfactants, and cosurfactants to obtain the most suitable combination of SMEDDS. Pseudoternary phase diagram was used to select the better oil/water formulation of SMEDDS. After a test for 3-month stability, dissolution tests and parallel artificial membrane permeability assay (PAMPA) were conducted to investigate drug solubility and permeability. Biodistribution of fluorescent marked SMEDDS was observed by using in vivo imaging system. The pharmacodynamics of the drug were determined by measuring blood pressure from tails of rats. At the end of the experiment, intestines were examined for adverse effects of OM. Compared with tablet formulation according to the dissolution study, SMEDDS formulation showed 1.67 times improvement in solubility of OM. PAMPA studies suggested a much faster permeability rate for OM SMEDDS compared to the suspension form. Labeled SMEDDS gave 3.96 times stronger fluorescent emission than control dye administered mice in in vivo imaging system (IVIS®) studies, indicating an increased bioavailability. Treating effect of SMEDDS was 3.1 times more efficient compared to suspension in hypertensive rats. It caused neither celiac-like enteropathy nor diarrhea, during 21-day noninvasive blood pressure system (NIBP) assay. Our results suggest that SMEEDS formulation improves dissolution and oral bioavailability of OM while reducing its adverse effects.

Enhancing Solubility and Bioavailability of Rosuvastatin into Self Nanoemulsifying Drug Delivery System.

OBJECTIVE: The aim of this study was to develop new Rosuvastatin calcium (RCa) self nanoemulsifying drug delivery system (SNEDDS) and to evaluate the bioavailability and pharmacodynamic effect of RCa-SNEDDS in Yorkshire pigs. METHODS: Firstly, SNEDDS was developed and prepared then RCa was incorporated into SNEDDS which was evaluated regarding their characterization, stability properties, drug release profiles, permeation and cytotoxicity studies. Finally, in vivo performance of RCa-SNEDDS (F1-RCa-SNEDDS) was examined by pharmacokinetic and pharmacodynamics studies. The average droplet size of RCa- SNEDDS ranged between 200 and 250 nm. RCa-SNEDDS that contained 12.8% Oleic acid, 11 % Labrafil M, 3.3 % Labrasol and 4.4 % Transcutol HP were found to be stable and exhibited approximately 4-fold higher permeation than commercial tablet (Crestor® 20 mg tablet). RESULTS: In pharmacokinetic studies, when F1-RCa-SNEDDS and commercial tablet were administered orally, F1-RCa-SNEDDS showed higher bioavailability of RCa than commercial tablet. Respectively, in pharmacodynamic studies, triglyceride and total cholesterol levels were significantly reduced with F1- RCa-SNEDDS formulation by 37% and 19% when compared to baseline values. CONCLUSION: However, these decreases with commercial formulation were only 6% and 2% respectively. According to these findings, development formulation could be potentially used to enhance the oral absorption of RCa.

Development and in vitro/in vivo evaluation of immediate release perindopril tablets.

Perindopril erbumine (PE) is a BCS (Biopharmaceutics Classification System) class 3 drug with high solubility and low permeability. It is an inhibitor of the enzyme that converts angiotensin I (Angiotensin Converting Enzyme, ACE) into angiotensin II as well as causing the degradation of the vasodilator bradykinin into an inactive heptapeptide. The aim of this study was to develop an alternative drug product by using a different salt of perindopril and to evaluate the bioequivalence between PE, not still licensed, and perindopril arginine (PA), licensed in many countries, and to prepare PE tablets by using direct compression method. Many different formulations were prepared, among which F3-coded formulation was only selected due to releasing of 98.03% active substance at 45th minute. Bioequivalence study was planned as a cross-designed, randomized, open-labeled, single-dose, single-center study and conducted in 24 male healthy volunteers via peroral route. The results of bioequivalence study were evaluated for Perindopril and Perindoprilat according to Cmax, tmax and AUC criteria. The geometric mean ratios (90% CI) of perindopril and perindoprilat followed test and reference drug were calculated for AUC0-t and Cmax, 105.946% (100.218-112.002%) and 110.437% (102.534-118.948%); 109.542% (98.364-121.992%) and 115.729% (101.031-132.565%), respectively. The 90% confidence intervals of them were found within the standard bioequivalence range (80-125%).

Does desloratadine alter the serum levels of montelukast when administered in a fixed-dose combination?

OBJECTIVES/HYPOTHESIS: The aim of this study was to investigate the serum levels of montelukast when administered alone or in combination with desloratadine. STUDY DESIGN: A prospective crossover study. METHODS: Twenty-three healthy volunteers were investigated in two sessions. Volunteers were given 10 mg of montelukast orally with 250 mL water in the first session. The same subjects were given 10 mg of montelukast in fixed combination with 5 mg desloratadine 10 days after first session. Blood samples were collected 2, 3, and 4 hours after drug administration, and kept at -80°C after both applications. Plasma samples were analyzed for montelukast concentration. RESULTS: Mean concentration values of both groups were not statistically different (P > .05), but the differences were statistically significant according to time (P < .05). Statistically significant difference was not found between the groups according to the area under curve on the basis of both marginal and cumulative values for all different time intervals (P > .05). CONCLUSIONS: The absorption rate of montelukast was not altered when administered with desloratadine. This study suggested that desloratadine does not influence the bioavailability of montelukast, and their combination therapy can be used safely.

The novel oral imatinib microemulsions: physical properties, cytotoxicity activities and improved Caco-2 cell permeability.

The objective of this study was to formulate imatinib (IM) loaded to water-in-oil (w/o) microemulsions as an alternative formulation for cancer therapy and to evaluate the cytotoxic effect of microemulsions Caco-2 and MCF-7. Moreover, permeability studies were also performed with Caco-2 cells. W/o microemulsion systems were developed by using pseudo-ternary phase diagram. According to cytotoxicity studies, all formulations did not exert a cytotoxic effect on Caco-2 cells. Furthermore, all formulations had a significant cytotoxic effect on MCF-7 cells and the cytotoxic effect of M3IM was significantly more than that of other microemulsions and IM solution (p < 0.05). The permeability studies of IM across Caco-2 cells showed that permeability value from apical to basolateral was higher than permeability value of other formulations. In conclusion, the microemulsion formulations as a drug carrier, especially M3IM formulation, may be used as an effective alternative breast cancer therapy for oral delivery of IM.

Effect of grapefruit juice on bioavailability of montelukast.

OBJECTIVES/HYPOTHESIS: The aim of this study was to investigate possible interactions between grapefruit juice and montelukast for up to 4 hours. STUDY DESIGN: A prospective, crossover study with 23 healthy volunteers was performed in two sessions. METHODS: In the first session, volunteers were treated with oral montelukast 10 mg once daily with 250 ml water. After a 10-day washout period, the same volunteers were treated with 10 mg montelukast with 250 ml grapefruit juice. Blood samples were collected 2, 3, and 4 hours after drug administration and kept at -80°C after both applications. Plasma samples were analyzed for montelukast concentration. RESULTS: The mean plasma concentration of montelukast across all time intervals was significantly greater (P = 0.0001) for those given grapefruit juice (517, 484, and 440) versus those treated with water (366, 356, and 292). Moreover, with respect to the time the sample was collected, there was no significant difference (P = 0.13) in the mean total plasma concentration up to 4 hours after montelukast ingestion for either group. There was a significant difference between the groups according to the area under curve with regard to marginal and cumulative values for all different time intervals (P < 0.05). CONCLUSIONS: Plasma concentration of montelukast was higher when administered with grapefruit juice, as compared to with water. This may have been due to the effect of grapefruit on liver metabolism of montelukast and the cytochrome P450 system.

Novel application of Eudragit RL and cholesteryl oleyl carbonate to thermo-sensitive drug delivery system.

The Eudragit RL 100 and propylene glycol (PG) membranes with and without cholesteryl oleyl carbonate (COC) were prepared by the solvent casting method to pioneer a novel application of a thermo-sensitive drug delivery system. After that, the properties of these membranes were investigated by thermal, scanning, and porosity studies. Drug permeation studies through all membranes were carried out using salbuthamol sulphate (SBS) at constant temperatures (25°C and 37°C), respectively. The permeability of SBS through the membranes with COC has been shown to be a discontinuous function of temperature, that is, their permeability increased steeply above the phase transition temperature (37°C) of the COC. The thermo-sensitive permeation mechanism for the membranes might be based on the structure change of the membranes caused by the phase transition, so that the membranes could absorb more water. Considering the high biological safety of Eudragit RL 100 and PG membranes with and without COC might be used to develop a novel thermo-sensitive drug delivery system.

Comparison of cefpodoxime proxetil release and antimicrobial activity from tablet formulations: complexation with hydroxypropyl-ß-cyclodextrin in the presence of water soluble polymer.

This study aims to prove the complexation of cefpodoxime proxetil (CP) by hydroxypropyl-ß-cyclodextrin (HP-ß-CD) in the presence of sodium carboxymethyl cellulose (Na CMC), and makes a comparison of commercial tablets by dissolution and antimicrobial activity studies. The CP--HP-ß-CD complex was prepared by kneading method and characterized by SEM, FTIR and DSC. The solubility method was used to investigate the effect of HP-ß-CD and Na CMC on the solubility of CP. The complex tablets were prepared using direct compression method. Dissolution studies were performed with complex tablets and commercial tablets in pH 1.2, 4.5, 6.8 and 7.4 buffer solutions. It was observed that complexation occurred in all formulations, and HP-ß-CD is able to increase CP solubility and dissolution rate of CP was improved from complex tablets, when compared with commercial tablets. Furthermore, the antimicrobial activity studies revealed that the CP--HP-ß-CD complex and complex tablets were shown to have more effective antimicrobial activity than commercial tablets. It is evident from the results that complexation with HP-ß-CD in the presence of Na CMC is feasible way to prepare a more efficient tablet formulation with improved dissolution and antimicrobial activity.

Effects of pesticides used in agriculture on the development of precocious puberty.

The present study aims to evaluate the effects of pesticides on premature breast development. Forty-five girls (group 1) with premature breast development living in the Menderes region, where greenhouse cultivation is the main income, 16 girls (group 2) living in Izmir city with early puberty, and 33 girls (group 3) who had no signs of puberty were included in the study. Endosulphan 1, endosulphan 2, endosulphan sulphate, methoxychlor, vinclozolin, 4,4-dichlorodiphenyldichlorethylene (DDE), 4,-dichlorodiphenyltrichloroethane (DDT), and 2,4-DDT were evaluated in the serum and adipose tissues of the groups by using a gas chromatography-mass spectrometry method. With the exception of 4,4'-DDE, the pesticides studied were undetectable in the serum and adipose tissue samples. The levels of basal luteinizing hormone (LH), stimulated LH, follicle-stimulating hormone, and the long axis of the uterus and both ovaries were significantly different in the girls who had premature thelarche and detectable 4,4'-DDE levels compared to the girls who had premature thelarche and undetectable 4,4'-DDE levels in serum and adipose tissues. The presence and levels of pesticides in serum and adipose tissues were not related to precocious puberty (PP). The mechanisms that lead to PP may also result in obesity, and obesity may be the underlying cause for PP in this group.

In vitro-in situ permeability and dissolution of fexofenadine with kinetic modeling in the presence of sodium dodecyl sulfate.

The purpose of this study was to estimate passive permeability and efflux transport parameters of fexofenadine (FEX) from in vitro cell culture and in situ rat experiments and determine the dissolution profile of FEX in the absence and presence of sodium dodecyl sulfate (SDS). The dissolution rate of FEX was investigated at different pH values and in the presence of SDS. The permeability of FEX was determined in situ in small intestine of Wistar rats and in vitro in Caco-2 cell monolayer. Permeability of FEX was determined at different donor concentrations, and the effect of SDS at two concentration levels (10 and 50 µM) on FEX permeability was evaluated. The transepithelial electrical resistance values of the in vitro technique were measured to assess monolayer integrity before and after the permeability studies. The FEX permeability parameters in the absence and presence of SDS were estimated using Phoenix WinNonlin software program and compared with other laboratory results for both in vitro and in situ studies. The results showed that FEX has a low permeability in the paracellular permeability as well a potential inhibition of secretion mediated by P-glycoprotein (P(gp)), and its permeability increased with presence of SDS. The dissolution of FEX was pH-dependent and significantly enhanced, especially in the presence of 50 mg SDS.

Acceleration of in vitro dissolution studies of sustained release dosage form of theophylline and in vitro-in vivo evaluations in terms of correlations.

The aim of the study was to accelerate the dissolution of the sustained release dosage forms using both elevated temperature and high rpm rates. Teokap(®) SR 200 mg pellets were tested by in vitro sustained and accelerated dissolution studies using USP XXIII rotating paddle method. Sustained dissolution studies were carried out for 12 h in phosphate buffer at 37 ± 0.5°C and 50 rpm. Accelerated dissolution studies were performed for 48 min in distilled water at 90 ± 1°C and 250 rpm. The results obtained from accelerated and sustained dissolution studies were correlated using both linear and linear kinetic correlation methods by a computer program. While r (2) and maximum error between calculated and observed drug release rates were found to be 0.9129 and 15.9%, respectively, in linear correlation method, these values were observed as 0.9938 and 3.6%, respectively, in linear kinetic correlation method. In vivo plasma concentration data were obtained from six New Zealand rabbits after administration of a single dose of Teokap(®) SR 200 mg pellet. Then, the results of in vivo study were evaluated with in vitro accelerated and sustained dissolution results by applying them to in vitro-in vivo linear correlations. As a result of these correlations, it was shown that the in vitro correlation plots were very similar to the plot which was obtained by the in vivo study (f (2) = 73.81-77.11). This study suggested a way to prevent the loss of time for routine dissolution studies of sustained release preparations for quality control procedures using in vitro accelerated dissolution tests. The storage and quarantine periods of the product in process and process controls in the manufactories could be shortened by this method. Calculation of the in vivo performance of sustained release dosage forms using the results of the accelerated dissolution studies may be counted as another advantage of the method.