How Does Radiation Affect Curcumin Raw Material?

Turmeric, known for its curcuminoid-rich rhizome, particularly curcumin, exhibits notable antioxidant and antiviral properties. The likelihood of microbial contamination necessitates finding reliable techniques for subjecting the sample to radiation from this plant-based raw material. One alternative is to expose curcumin to radiation (e-beam), which was carried out as part of this research. Confirmation of the lack of curcumin decomposition was carried out using HPLC-DAD/MS techniques. Additionally, using the EPR technique, the generated free radicals were defined as radiation effects. Using a number of methods to assess the ability to scavenge free radicals (DPPH, ABTS, CUPRAC, and FRAP), a slight decrease in the activity of curcumin raw material was determined. The analysis of the characteristic bands in the FT-IR spectra allowed us to indicate changes in the phenolic OH groups as an effect of the presence of radicals formed.

Sinapic Acid Co-Amorphous Systems with Amino Acids for Improved Solubility and Antioxidant Activity.

The objective of this study was to obtain co-amorphous systems of poorly soluble sinapic acid using amino acids as co-formers. In order to assess the probability of the interaction of amino acids, namely, arginine, histidine, lysine, tryptophan, and proline, selected as co-formers in the amorphization of sinapic acid, in silico studies were carried out. Sinapic acid systems with amino acids in a molar ratio of 1:1 and 1:2 were obtained using ball milling, solvent evaporation, and freeze drying techniques. X-ray powder diffraction results confirmed the loss of crystallinity of sinapic acid and lysine, regardless of the amorphization technique used, while remaining co-formers produced mixed results. Fourier-transform infrared spectroscopy analyses revealed that the co-amorphous sinapic acid systems were stabilized through the creation of intermolecular interactions, particularly hydrogen bonds, and the potential formation of salt. Lysine was selected as the most appropriate co-former to obtain co-amorphous systems of sinapic acid, which inhibited the recrystallization of sinapic acid for a period of six weeks in 30 °C and 50 °C. Obtained co-amorphous systems demonstrated an enhancement in dissolution rate over pure sinapic acid. A solubility study revealed a 12.9-fold improvement in sinapic acid solubility after introducing it into the co-amorphous systems. Moreover, a 2.2-fold and 1.3-fold improvement in antioxidant activity of sinapic acid was observed with respect to the ability to neutralize the 2,2-diphenyl-1-picrylhydrazyl radical and to reduce copper ions, respectively.

Do Rutin and Quercetin Retain Their Structure and Radical Scavenging Activity after Exposure to Radiation?

The influence of ionizing radiation on the physicochemical properties of quercetin and rutin in the solid state was studied. Quercetin and rutin were irradiated with the standard recommended radiation dose (25 kGy) according to EN 522 standard. The samples were irradiated by electron beam radiation. EPR studies indicate the formation of a small number of free radicals due to irradiation. Moreover, some radicals recombined with the mean lifetime of 1200 and 93 h, and a stable radical concentration reached only 0.29 and 0.90 ppm for quercetin and rutin, respectively. The performed spectroscopic study (FT-IR) confirmed the radiostability of the flavonoids tested. Chromatographic tests (HPLC, HPLC-MS) showed that irradiation of quercetin and rutin with a 25 kGy dose did not change the physicochemical properties of the tested compounds. Degradation products were not observed. The antioxidant activities were determined by the 2,2-diphenyl-1-pycrylhydrazyl (DPPH) free radical scavenging activity assay, ABTS Radical Scavenging Assay (ABTS), Ferric Reducing Antioxidant Power Assay (FRAP), Cupric Ion Reducing Antioxidant Capacity Assay (CUPRAC). The conducted research confirmed that exposure to ionizing radiation does not change the chemical structure of tested flavonoids and their antioxidant properties.

Anticholinesterase and Antityrosinase Secondary Metabolites from the Fungus Xylobolus subpileatus.

Xylobolus subpileatus is a widely distributed crust fungus reported from all continents except Antarctica, although considered a rare species in several European countries. Profound mycochemical analysis of the methanol extract of X. subpileatus resulted in the isolation of seven compounds (1-7). Among them, (3ß,22E)-3-methoxy-ergosta-4,6,814,22-tetraene (1) is a new natural product, while the NMR assignment of its already known epimer (2) has been revised. In addition to a benzohydrofuran derivative fomannoxin (3), four ergostane-type triterpenes 4-7 were identified. The structure elucidation of the isolated metabolites was performed by one- and two-dimensional NMR and MS analysis. Compounds 2-7 as well as the chloroform, n-hexane, and methanol extracts of X. subpileatus were evaluated for their tyrosinase, acetylcholinesterase, and butyrylcholinesterase inhibitory properties. Among the examined compounds, only fomannoxin (3) displayed the antityrosinase property with 51% of inhibition, and the fungal steroids proved to be inactive. Regarding the potential acetylcholinesterase (AChE) inhibitory activity of the fungal extracts and metabolites, it was demonstrated that the chloroform extract and compounds 3-4 exerted noteworthy inhibitory activity, with 83.86 and 32.99%, respectively. The butyrylcholinesterase (BChE) inhibitory assay revealed that methanol and chloroform extracts, as well as compounds 3 and 4, exerted notable activity, while the rest of the compounds proved to be only weak enzyme inhibitors. Our study represents the first report on the chemical profile of basidiome of the wild-growing X. subpileatus, offering a thorough study on the isolation and structure determination of the most characteristic biologically active constituents of this species.

Genistein-Opportunities Related to an Interesting Molecule of Natural Origin.

Nowadays, increasingly more attention is being paid to a holistic approach to health, in which diet contributes to disease prevention. There is growing interest in functional food that not only provides basic nutrition but has also been demonstrated to be an opportunity for the prevention of disorders. A promising functional food is soybean, which is the richest source of the isoflavone, genistein. Genistein may be useful in the prevention and treatment of such disorders as psoriasis, cataracts, cystic fibrosis, non-alcoholic fatty liver disease and type 2 diabetes. However, achievable concentrations of genistein in humans are low, and the use of soybean as a functional food is not devoid of concerns, which are related to genistein's potential side effects resulting from its estrogenic and goitrogenic effects.

The Radiation Sterilization of Ertapenem Sodium in the Solid State.

For the first time, the influence of ionising radiation on the physicochemical properties of ertapenem in solid state was studied. During our studies, we evaluated the possibility of applying radiosterilization to obtain sterile ertapenem. Spectroscopic (Fourier Transform Infrared (FT-IR)), thermal (differential scanning calorimetry (DSC), chromatography (High-Performance Liquid Chromatography (HPLC) and HPLC-MS), and X-ray powder diffraction (XRPD) studies shown that irradiation of ertapenem with the 25 kGy, the dose required to achieve sterility, does not change the physicochemical properties of the studied compound. The antimicrobial activity of ertapenem irradiated with the dose of 25 kGy was only reduced for one species. Based on the received results, we can conclude that radiostelization is a promising alternative method of obtaining sterile ertapenem. In our studies, ertapenem was also exposed to e-beam radiation with a dose of 400 kGy. It was determined that two novel degradation products that are structurally differently to degradants formed during hydrolysis and thermolysis.

The Analysis of the Physicochemical Properties of Benzocaine Polymorphs.

The study was a pioneering attempt to assess the influence of the structural polymorphism (forms I, II, III) of benzocaine on its solubility, apparent solubility, and chemical stability, which are vital parameters for preformulation and formulation work. The impact of differences in the solubility of selected polymorphs of benzocaine on their permeability through artificial biological membranes (PAMPA system) was evaluated. The polymorphs of benzocaine were obtained by means of techniques commonly used for the preparation of various pharmaceutical dosage forms: ball milling, micro milling, and cryogenic grinding, which allowed for the appearance or preservation of form III, the initial conformation of benzocaine. Ball milling resulted in the conversion of form III to I, whereas micro milling yielded form II. As a result of cryogenic grinding, form III of benzocaine was preserved. The identification of all polymorphic forms of benzocaine was confirmed via X-ray powder diffraction (PXRD) supported by FT-IR spectroscopy coupled with density functional theory (DFT) calculations. The differences in solubility, dissolution, and permeability through artificial biological membranes resulting from the polymorphic forms of benzocaine were established by using chromatographic determinations. Accelerated stability tests indicated that all polymorphic forms were chemically stable at a required level.

The Radiostability of Meropenem Trihydrate in Solid State.

The influence of ionising radiation on the physicochemical properties of meropenem trihydrate in solid state was studied for doses of e-beam radiation: 25 kGy and 400 kGy. In the first part of our studies, we evaluated the possibility of applying radiosterilization to obtain sterile meropenem. No changes for meropenem irradiated with a dose of 25 kGy, the dose required to attain sterility, was confirmed in the results of spectroscopic (FT-IR), thermal (DSC, TGA) and X-ray powder diffraction (XRPD) studies. The radiation dose of 25 kGy produces no more than about 1500 ppm of radical defects. The chromatographic studies of irradiated meropenem in solutions did not show any chemical degradation. Moreover, the antimicrobial activity of meropenem irradiated with the dose of 25 kGy was unchanged. Based on the received results, we can conclude that radiostelization is a promising, alternative method for obtaining sterile meropenem. In the second part of the research, meropenem was exposed to e-beam radiation at the 400 kGy dose rate. It was confirmed, that reducing of antimicrobial activity could be connected with the degradation of ß-lactam ring and changes in the trans-hydroxyethyl group. Apart from chemical changes, changes in the physical stability of irradiated meropenem (400 kGy) was also observed.

Renal cell carcinoma metastasizing to pancreatic neuroendocrine neoplasm - the second case described in the world literature.

Tumor-to-tumor metastases are very rare events. We report a case of a 64-year-old man who presented with a tumor of the pancreas. The patient underwent partial pancreatectomy. Frozen section diagnosis of the tumor was an endocrine neoplasm. Paraffin block slide examination revealed a tumor consisting of two components: pancreatic endocrine neoplasm at the periphery of the tumor and the central part composed of clear cells with delicate vessels. The results of immunohistochemical stains revealed renal cell carcinoma surrounded by pancreatic endocrine neoplasm, therefore representing an unusual case of renal cell carcinoma metastasizing to a pancreatic endocrine neoplasm.

Solid-state stability studies of crystal form of tebipenem.

The aim of this study was to determine the kinetic and thermodynamic parameters of tebipenem degradation in the solid state. The process was analyzed based on the results obtained by a high performance liquid chromatography (HPLC) method using ultraviolet diode-array detector (DAD)/electrospray ionization tandem mass spectrometry (Q-TOF-MS/MS), Fourier transform infrared spectroscopy (FT-IR) and Raman spectroscopic (RS) studies. In dry air, the degradation of tebipenem was a first-order reaction depending on the substrate concentration while at an increased relative air humidity tebipenem was degraded according to the kinetic model of autocatalysis. The thermodynamic parameters: energy of activation (Ea), enthalpy (ΔH(≠a)) and entropy (ΔS(≠a)) of tebipenem degradation were calculated. Following a spectroscopic analysis of degraded samples of tebipenem, a cleavage of the ß-lactam bond was proposed as the main degradation pathway, next confirmation using HPLC-Q-TOF-MS/MS method.

Stability of cefozopran hydrochloride in aqueous solutions.

The influence of pH on the stability of cefozopran hydrochloride (CZH) was investigated in the pH range of 0.44-13.00. Six degradation products were identified with a hybrid ESI-Q-TOF mass spectrometer. The degradation of CZH as a result of hydrolysis was a pseudo-first-order reaction. As general acid-base hydrolysis of CZH was not occurred in the solutions of hydrochloric acid, sodium hydroxide, acetate, borate and phosphate buffers, kobs = kpH because specific acid-base catalysis was observed. Specific acid-base catalysis of CZH consisted of the following reactions: hydrolysis of CZH catalyzed by hydrogen ions (kH+), hydrolysis of dications (k1H2O), monocations (k2H2O) and zwitter ions (k3H2O) and hydrolysis of zwitter ions (k1OH-) and monoanions (k2OH-) of CZH catalyzed by hydroxide ions. The total rate of the reaction was equal to the sum of partial reactions: [Formula: see text]. CZH similarly like other fourth generation cephalosporin was most stable at slightly acidic and neutral pH and less stable in alkaline pH. The cleavage of the ß-lactam ring resulting from a nucleophilic attack on the carbonyl carbon in the ß-lactam moiety is the preferred degradation pathway of ß-lactam antibiotics in aqueous solutions.

A SIMPLE AND-SENSITIVE STABILITY-INDICATING UHPLC-DAD METHOD FOR THE DETERMINATION OF CEFETAMET PIVOXIL HYDROCHLORIDE.

A fast and sensitive UHPLC-DAD method was developed and subsequently validated for determination of cefetamet pivoxil hydrochloride in the presence of its degradation products. The chromatographic separation was carried out on a Waters Acquity BEH C18, (2.1 x 100 mm, 1.7 µm) column. The mobile phase was composed of 0.1% formic acid and acetonitrile (40 : 60, v/v) at the flow rate 0.7 mL/min. The detection wavelength was 265 nm and the temperature was 30 °C. Cefetamet pivoxil hydrochloride was susceptible to degradation under the influence of sodium hydroxide, hydrochloric acid and in the conditions of increased temperature and relative humidity. However, it was stable after irradiation, in increased temperature in dry air and in the presence of oxidizing agent. The developed UHPLC-DAD method was linear over the concentration range of 10-240 µg/mL (r2 = 0.9999; n = 12). The obtained RSD values were less than 2%, demonstrating that the described procedure is precise. The accuracy was also confirmed (mean recoveries were 97.79-102.08%). Under applied chromatographic conditions LOD and LOQ values were 2.08 mg/mL and 6.29 mg/mL, respectively. The proposed method was successfully applied in determination of cefetamet pivoxil hydrochloride in aqueous solutions as well as in the solid state.

STABILITY OF CEFPIROME SULFATE IN AQUEOUS SOLUTIONS.

The influence of pH on the stability of cefpirome sulfate was investigated in the pH range of 0.44 - 13.00. The degradation of cefpirome sulfate as a result of hydrolysis was a pseudo-first-order reaction. General acid-base hydrolysis of cefpirome sulfate was not observed. In the solutions of hydrochloric acid, sodium hydroxide, acetate, borate and phosphate buffer, k(obs) = k(pH) because specific acid-base catalysis was observed. Specific acid-base catalysis of cefpirome sulfate consisted of the following reactions: hydrolysis of cefpirome sulfate catalyzed by hydrogen ions (kH+), hydrolysis of dications (k1H2O) monocations (k2 H2O), zwitter ions (k3H2O) and monoanions (k4 H2O) of cefpirome sulfate under the influence of water. The total rate of the reaction was equal to the sum of partial reactions k(pH) = kH+ x aH+ + kH2O x f1 + k2H2O x f2 + k3H2O x f3 + k4 H2O x f4. Based on the dependence k(pH) = f(pH) it was found that cefpirome sulfate was the most stable in aqueous solutions in the pH range of 4-6.

STUDIES OF THE CRYSTALLINE FORM OF CEFUROXIME AXETIL: IMPLICATIONS FOR ITS COMPATIBILITY WITH EXCIPIENTS.

Amorphous and crystalline forms of cefuroxime axetil were identified and characterized using DSC, XRPD, SEM, FT-IR and Raman spectroscopy. Based on the results of chromatographic studies, changes in the kinetic mechanism and rate of degradation of the crystalline form of cefuroxime axetil in binary systems with excipients were also evaluated. The findings suggest that the mechanism of degradation of cefuroxime axetil in such systems depends on two factors: the applied excipient and storage conditions. Cefuroxime axetil in combination with magnesium stearate, croscarmellose sodium and crospovidone, microcrystalline cellulose, aerosil is decomposed according to the first-order reaction model in dry air as well as at an increased relative air humidity, which may be associated with non-catalytic interactions between the active pharmaceutical ingredient and the excipients. However, in the presence of mannitol, under elevated humidity conditions (RH - 76%), the degradation of cefuroxime axetil follows the autocatalytic model. According to ESP maps, computed binding energies and HOMO - LUMO gaps, differences of degradation curves between cefuroxime axetil - mannitol and other investigated systems were explained. This study of the polymorphic transformation of the crystalline form of cefuroxime axetil and its binary systems with excipients after exposure to increased temperature and humidity indicated a conversion towards the amorphous form or the coexistence of both forms.

Application of vibrational spectroscopy supported by theoretical calculations in identification of amorphous and crystalline forms of cefuroxime axetil.

FT-IR and Raman scattering spectra of cefuroxime axetil were proposed for identification studies of its crystalline and amorphous forms. An analysis of experimental spectra was supported by quantum-chemical calculations performed with the use of B3LYP functional and 6-31G(d,p) as a basis set. The geometric structure of a cefuroxime axetil molecule, HOMO and LUMO orbitals, and molecular electrostatic potential were also determined by using DFT (density functional theory). The benefits of applying FT-IR and Raman scattering spectroscopy for characterization of drug subjected to degradation were discussed.

Solid-state stability and compatibility studies of clavulanate potassium.

The kinetic and thermodynamic parameters of degradation of clavulanate potassium in the solid state were studied by using a reversed phase high performance liquid chromatography (RP-HPLC) method. The degradation of clavulanate potassium was a first-order reaction depending on the substrate concentration at an increased relative air humidity (RH) and in dry air. The dependence ln k = f(1/T) became the ln k = (0.026 ± 166.35)-(2702.82 ± 1779.43)(1/T) in dry air and ln k = (1.65 ± 100.40) × 10(3)-(5748.81 ± 3659.67)(1/T) at 76.4% RH. The thermodynamic parameters Ea, ΔH(≠a), ΔS(≠a) of the degradation of clavulanate potassium in the solid state were calculated. The dependence ln k = f (RH%) assumed the form ln k = (8.78 ± 5.75) 10 (-2) (RH%) + (2.64 × 10(-8 )± 40.41). The compatibility of clavulanate potassium with commonly used excipients was studied at an increased temperature and in dry air. The geometric structure of molecule, highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) orbitals were also determined in order to predict the structural changes and reactive sites in clavulanate potassium during degradation and compatibility studies in the solid state. The ultraviolet (UV), Fourier transform infrared spectroscopy (FT-IR) and Raman spectra of degraded samples of the compound were analyzed.

DEVELOPMENT AND VALIDATION OF THE STABILITY-INDICATING LC-UV METHOD FOR DETERMINATION OF CEFOZOPRAN HYDROCHLORIDE.

The stability-indicating LC assay method was developed and validated for quantitative determination of cefozopran hydrochloride (CZH) in the presence of degradation products formed during the forced degradation studies. An isocratic, RP-HPLC method was developed with C-18 (250 mm x 4.6 mm, 5 µm) column and 12 mM ammonium acetate-acetonitrile (92:8, v/v) as a mobile phase. The flow rate of the mobile phase was 1.0 mL/min. Detection wavelength was 260 not and temperature was 30°C. Cefozopran hydrochloride as other cephalosporins was subjected to stress conditions of degradation in aqueous solutions including hydrolysis, oxidation, photolysis and thermal degradation. The developed method was validated with regard to linearity, accuracy, precision, selectivity and robustness. The method was applied successfully for identification and determination of cefozopran hydrochloride in pharmaceuticals and during kinetic studies.

An Approach to Transfer Methods from HPLC to UHPLC Techniques in Some Carbapenems.

Stability-indicating LC methods were developed and validated for the quantitative determination of doripenem, meropenem and tebipenem in the presence of their degradation products formed during forced degradation studies. Isocratic HPLC and UHPLC separations were performed with a core-shell Kinetex 1.7, 2.6 and 5 µm, all C18, 100A, 100 × 2.1 mm columns and the mobile phase composed of acetonitrile and 12 mmol L-1 ammonium acetate in different ratios. The flow rates of the mobile phase were: 0.5 mL min-1 for 1.7 µm column, and 1.0 mL min-1 for 2.6 and 5 µm ones. Detection wavelength was 298 nm and temperature was set at 30 °C. All analysed drugs were exposed to stress conditions which caused their hydrolysis and thermal degradation. The methods were validated by evaluation of linearity, accuracy, precision, selectivity and robustness. Proposed methods were successfully applied for the determination of investigated antibiotics during kinetic studies in aqueous solutions and in the solid state. The advantages of chromatographic procedures which are based on the use of C18 stationary phases with different particle sizes in the analysis of selected carbapenems were discussed.

Assay of Diastereoisomers of Cefuroxime Axetil in Amorphous and Crystalline Forms Using UHPLC-DAD.

A sensitive UHPLC-DAD method was developed for determination of diastereoisomers of cefuroxime axetil in bulk substance in amorphous and crystalline forms as well as in pharmaceutical preparations. Chromatographic separation was achieved on Kinetex C-18 (100 mm × 2.1 mm, 1.7 µm) column with mobile phase consisting of 0.1 % formic acid:methanol (88:12, v/v), at the flow rate of 0.7 mL min-1 and total run time of 3 min. The wavelength of the DAD detector was set at 278 nm. Inter-day precision (RSD) was less than 3 % and accuracy level ranged between 98.31 and 104.99 %. Degradation products of cefuroxime axetil in aqueous solutions and in the solid state were identified with a EIS-Q-MS mass spectrometer. The solubility of above-mentioned polymorphic forms of cefuroxime axetil in suitable solvents is a crucial factor during preparation of samples and is essential for chromatographic separation of its diastereoisomers.

The Development and Validation of a Stability-Indicating UHPLC-DAD Method for Determination of Perindopril l-Arginine in Bulk Substance and Pharmaceutical Dosage Form.

A stability-indicating ultra-high-performance liquid chromatography (UHPLC) method with a diode array detector was developed and validated for the determination of cis/trans isomers of perindopril l-arginine in bulk substance and pharmaceutical dosage form. The separation was achieved on a Poroshell 120 Hilic (4.6 × 150 mm, 2.7 µm) column using a mobile phase composed of acetonitrile-0.1 % formic acid (20:80 v/v) at a flow rate of 1 mL min-1. The injection volume was 5.0 µL and the wavelength of detection was controlled at 230 nm. The selectivity of the UHPLC-DAD method was confirmed by determining perindopril l-arginine in the presence of degradation products formed during acid-base hydrolysis and oxidation as well as degradation in the solid state, at an increased relative air humidity and in dry air. The method's linearity was investigated in the ranges 0.40-1.40 µg mL-1 for isomer I and 0.40-2.40 µg mL-1 for isomer II of perindopril l-arginine. The UHPLC-DAD method met the precision and accuracy criteria for the determination of the isomers of perindopril l-arginine. The limits of detection and quantitation were 0.1503 and 0.4555 µg mL-1 for isomer I and 0.0356 and 0.1078 µg mL-1 for isomer II, respectively.