Assessing β-Sitosterol Levels in Dietary Supplements for Benign Prostatic Hyperplasia: Implications for Therapeutic Efficacy

Introduction Benign prostatic hyperplasia (BPH) is a prevalent condition among aging men that affects their life quality due to urinary symptoms. Current pharmacologic treatments, often lead to sexual dysfunction, so dietary supplements (DS) containing plant-based compounds such as β-sitosterol (SIT) are preferred. DS are highly accessible and widely used, but poorly regulated, so often patients are victims of fraud. The use of DS to treat BPH symptoms is questionable, and this may be due not to the efficacity of the active compound but to the quality of commonly available DS. Aim This study aimed to assess the concentration of SIT in DS available on the market and evaluate whether the concentration of the active compound at the recommended dosage is sufficient to elicit beneficial effects in BPH. Method An HPLC-UV method based on direct saponification and acid hydrolysis was developed for the quantification of free and conjugated SIT in DS. The concentration of SIT in various DS was determined and compared with the one declared on the label. Results The chromatographic analysis confirmed the presence of SIT in all the DS but also showed a considerable variability of SIT content among DS, with only one product meeting the necessary concentration to bring potential benefits in BPH. Conclusion The study highlights inconsistencies in SIT content among DS and the importance of DS containing a standardized extract of SIT. Quality control measures are imperative to ensure that consumers receive effective and safe SIT-based DS to manage BPH symptoms. Further research is needed to establish standardized dosages and to evaluate their long-term efficacy and safety.

Is it Time to Migrate to Liquid Chromatography Automated Platforms in the Clinical Laboratory? A Brief Point of View

Liquid chromatography coupled to mass spectrometry already started to surpass the major drawbacks in terms of sensitivity, specificity and cross-reactivity that some analytical methods used in the clinical laboratory exhibit. This hyphenated technique is already preferred for specific applications while finding its own place in the clinical laboratory setting. However, large-scale usage, high-throughput analysis and lack of automation emerge as shortcomings that liquid chromatography coupled to mass spectrometry still has to overrun in order to be used on a larger scale in the clinical laboratory. The aim of this review article is to point out the present-day position of the liquid chromatography coupled to mass spectrometry technique while trying to understand how this analytical method relates to the basic working framework of the clinical laboratory. This paper offers insights about the main regulation and traceability criteria that this coupling method has to align and comply to, automation and standardization issues and finally the critical steps in sample preparation workflows all related to the high-throughput analysis framework. Further steps are to be made toward automation, speed and easy-to-use concept; however, the current technological and quality premises are favorable for chromatographic coupled to mass spectral methods.

Enantioselective binding of carvedilol to human serum albumin and alpha-1-acid glycoprotein

Carvedilol, a highly protein-bound beta-blocker, is used in therapy as a racemic mixture of its two enantiomers that exhibit different pharmacological activity. The aim of this study was to evaluate the stereoselective nature of its binding to the two major plasma proteins: albumin and alpha-1-acid glycoprotein. The determination of the plasma protein-binding degree for carvedilol and its enantiomers was achieved using ultrafiltration for the separation of the free fraction, followed by LC-MS/MS quantification, using two different developed and validated methods in terms of stationary phase: achiral C18 type and chiral ovomucoid type. Furthermore, molecular docking methods were applied in order to investigate and to better understand the mechanism of protein-binding for S-(-)- and R-(+)-carvedilol. A difference in the binding behavior of the two enantiomers to the plasma proteins was observed when taken individually, with R-(+)-carvedilol having a higher affinity for albumin and S-(-)-carvedilol for alpha-1-acid glycoprotein. However, in the case of the racemic mixture, the binding of the S enantiomer to alpha-1-acid glycoprotein seemed to be influenced by the presence of its antipode, although no such influence was observed in the case of albumin. The results raise the question of a binding competition between the two enantiomers for alpha-1-acid glycoprotein.

LC-MS/MS assisted biomonitoring of ropivacaine and 3-OH-ropivacaine after plane block anesthesia for cardiac device implantation

Introduction: Ropivacaine is a popular local anesthetic used for regional anesthesia or for pain management. Although designed as an enantiomerically pure drug, an aspect that reduces the adverse effects, its toxicological effects are still a risk. As such, biomonitoring to assure appropriate dosage and bioavailability are essential to avoid complications during or post-surgery. Methods: The study focused on developing a sensitive, selective, and accurate liquid chromatography-mass spectrometry (LCMS/MS) method which facilitates the biomonitoring of ropivacaine and its main metabolite in plasma after regional anesthesia using ropivacaine. Results and Discussion: The method was validated with regards to all relevant parameters, such as sensitivity, selectivity, accuracy, precision, and the effect of sample matrix. The method was successfully used in a pilot study, which included one patient undergoing plane block anesthesia for cardiac device implantation. The results showed the method is appropriate for its intended purpose and could even be used in other, similar applications.

Stability of Oral Liquid Dosage Forms in Pediatric Cardiology: A Prerequisite for Patient's Safety-A Narrative Review

The development of safe and effective pediatric formulations is essential, especially in therapeutic areas such as pediatric cardiology, where the treatment requires multiple dosing or outpatient care. Although liquid oral dosage forms are considered the formulation of choice given the dose flexibility and acceptability, the compounding practices are not endorsed by the health authorities, and achieving stability can be problematic. The purpose of this study is to provide a comprehensive overview of the stability of liquid oral dosage forms used in pediatric cardiology. An extensive review of the literature has been performed, with a particular focus on cardiovascular pharmacotherapy, by consulting the current studies indexed in PubMed, ScienceDirect, PLoS One, and Google Scholar databases. Regulations and guidelines have been considered against the studies found in the literature. Overall, the stability study is well-designed, and the critical quality attributes (CQAs) have been selected for testing. Several approaches have been identified as innovative in order to optimize stability, but opportunities to improve have been also identified, such as in-use studies and achieving dose standardization. Consequently, the information gathering and the results of the studies can be translated into clinical practice in order to achieve the desired stability of liquid oral dosage forms.

The Lack of Standardization and Pharmacological Effect Limits the Potential Clinical Usefulness of Phytosterols in Benign Prostatic Hyperplasia

The prevalence of benign prostatic hyperplasia (BPH) markedly increases with age. Phytotherapeutic approaches have been developed over time owing to the adverse side effects of conventional medications such as 5-reductase inhibitors and α1-adrenergic receptor antagonists. Therefore, dietary supplements (DS) containing active compounds that benefit BPH are widely available. Phytosterols (PSs) are well recognized for their role in maintaining blood cholesterol levels; however, their potential in BPH treatment remains unexplored. This review aims to provide a general overview of the available data regarding the clinical evidence and a good understanding of the detailed pharmacological roles of PSs-induced activities at a molecular level in BPH. Furthermore, we will explore the authenticity of PSs content in DS used by patients with BPH compared to the current legislation and appropriate analytical methods for tracking DS containing PSs. The results showed that PSs might be a useful pharmacological treatment option for men with mild to moderate BPH, but the lack of standardized extracts linked with the regulation of DS containing PSs and experimental evidence to elucidate the mechanisms of action limit the use of PSs in BPH. Moreover, the results suggest multiple research directions in this field.

Methods and Strategies for Biomonitoring in Occupational Exposure to Plant Protection Products Containing Glyphosate

Glyphosate, and the ever growing reliance on its use in agriculture, has been a point of contention for many years. There have been debates regarding the risk and safety of using glyphosate-based herbicides as well as the effects of occupational, accidental, or systematic. Although there have been a number of studies conducted, the biomonitoring of glyphosate poses a series of challenges. Researchers attempting to determine the occupational exposure face questions regarding the most appropriate analytical techniques and sampling procedures. The present review aims to summarize and synthetize the analytical methodologies available and suitable for the purpose of glyphosate biomonitoring studies as well as discuss the advantages and disadvantages of each analytical technique, from the most modern to more well-established and older ones. The most relevant publications that have described analytical methods and published within the last 12 years were studied. Methods were compared, and the advantages and disadvantages of each methods were discussed. A total of 35 manuscripts describing analytical methods for glyphosate determination were summarized and discussed, with the most relevant one being compared. For methods that were not intended for biological samples, we discussed if they could be used for biomonitoring and approaches to adapt these methods for this purpose.

Fatty Acids and Lipid Paradox-Neuroprotective Biomarkers in Ischemic Stroke

Stroke is the primary cause of death and disability worldwide, with ischemic stroke up to 80% of the total cases. Lipid profile was established as a major risk factor for stroke, but recent studies show a paradoxical relationship between serum values and the outcome of stroke patients. Our study aims to analyze the impact of the classic extended lipid profile, including fatty acids as potential neuroprotective biomarkers for the outcome of ischemic stroke patients. We included 298 patients and collected clinical, paraclinical, and outcome parameters. We used a method consisting of high-performance liquid chromatography coupled with mass spectrometry to quantify serum fatty acids. We observed a negative correlation between National Institutes of Health Stroke Scale (NIHSS) at admission and total cholesterol (p = 0.040; r = −0.120), respectively triglycerides (p = 0.041; r = −0.122). The eicosapentaenoic to arachidonic acid ratio has a negative correlation, while the docosahexaenoic to eicosapentaenoic acid ratio positively correlates with all the prognostic parameters, showing a potential neuroprotective role for eicosapentaenoic acid in preventing severe ischemic stroke. The impact of the lipid profile paradox and the dependency relationship with the fatty acids represent a significant predictive factor for the functional and disability prognostic of ischemic stroke patients.

Off-Label Medication: From a Simple Concept to Complex Practical Aspects

Off-label use of drugs is widely known as unapproved use of approved drugs, and it can be perceived as a relatively simple concept. Even though it has been in existence for many years, prescribing and dispensing of drugs in an off-label regimen is still a current issue, triggered especially by unmet clinical needs. Several therapeutic areas require off-label approaches; therefore, this practice is challenging for prescribing physicians. Meanwhile, the regulatory agencies are making efforts in order to ensure a safe practice. The present paper defines the off-label concept, and it describes its regulation, together with several complex aspects associated with clinical practices regarding rare diseases, oncology, pediatrics, psychiatry therapeutic areas, and the safety issues that arise. A systematic research of the literature was performed, using terms, such as “off-label”, ”prevalence”, ”rare diseases”, ”oncology”, ”psychiatry”, ”pediatrics”, and ”drug repurposing”. There are several reasons for which off-label practice remains indispensable in the present; therefore, efforts are made worldwide, by the regulatory agencies and governmental bodies, to raise awareness and to ensure safe practice, while also encouraging further research.

Pharmacotechnical and analytical preformulation studies for cannabidiol orodispersible tablets

Obtaining orodispersible tablets (ODT) containing substances from the second Biopharmaceutical Class has raised concerns as the dissolution test is challenging. This study aimed to select suitable excipients for developing orodispersible tablets containing cannabidiol (CBD) by direct compression method. No similar studies were found in the literature. Excipients from different classes were characterized using the SeDeM-ODT tool: fillers – lactose (LCT) and microcrystalline cellulose (CelMC), sweeteners – sorbitol (SRB) and mannitol (MNT), disintegrants – sodium starch glycolate (SSG), sodium croscarmellose (CCS), soy polysaccharides (Emcosoy® – EMCS) and two co-processed excipients (Prosolv®-ODT G2 – PODTG2 and Prosolv® EasyTab sp – PETsp). Drug compatibility with excipients in binary mixtures (1:1) was verified by Differential Scanning Calorimetry (DSC) and Fourier Transform-Infrared (FTIR) spectroscopy. Using the SeDeM-ODT expert system, the fillers and the co-processed excipients showed good properties regarding compressibility and disintegration behavior. Also, the DSC and FTIR results showed that small or no interactions between the CBD and the excipients took place.

Development of an Analytical Methodology for the Qualitative and Quantitative Characterization of Capsules with Andarine, in Order to Use them to Investigate the Pharmacotoxicological Profile of the Substance

Andarine is one of the most commonly used doping substance between selective androgen receptor modulators (SARMs). The purpose of our study is to characterize qualitatively and quantitatively andarine capsules purchased legally via the Internet through a rapid and precise UHPLC method and the uniformity of mass, content and dissolution assays were determined following the methodology of the European Pharmacopoeia 8th Ed. Regarding the uniformity of mass, the capsules are within the permissible limits, but regarding the active substance content, an average of 4.99 mg of andarine/capsule was obtained (with an RSD of 5.41%) from the 25 mg/capsule declared by the manufacturer.

With or Without Internal Standard in HPLC Bioanalysis. A Case Study

The mandatory strategy of using internal standard in HPLC is still controversial. Despite that the introduction of internal standard methodology in the early stage of development of HPLC technology was used to improve method accuracy and precision, there are still practical situations in which a simple external standard quantification is adequate. The aim of the study is to compare the determination of meloxicam (MXC) in human plasma by HPLC with or without using an internal standard according to some key points related to the reason of introducing the internal standardization such as the reducing of sample preparation errors or variability for low injection volumes. The HPLC analysis was performed on reversed phase with UV detection after protein precipitation. Piroxicam (PXC) was used as an internal standard. The two methods are compared in terms of accuracy and precision over the same concentration range. The stability of the analyte has been proved. According to the results, the quantitative determination of MXC in human plasma after simple protein precipitation by using PXC as an internal standard does not bring any significant improvement of accuracy and precision of the experimental measurements.

Water Hardness Key Element in Choosing Between Washing Efficiency with Enzyme Detergent and the Lifespan of the Washing Machine

The use of detergents with enzymatic activity is very popular if we consider their real economic advantages - reducing energy and water consumption but also reducing the environmental impact by using more biodegradable components related to organic and inorganic components. The purpose of our study was to evaluate the impact of environmental factors such as the variability of water hardness in the public water supply network and the temperature applied to the amylolytic, lipolytic and proteolytic enzyme activity of 6 detergents available on the market. The determinations were performed by modified methods from the European Pharmacopoeia 8th Edition in determination the enzymatic activity of the pancreas powder. The determinations show a significant influence of increased water hardness on lipase and protease activity in detergent (p [0.01 *) between extreme hardness values, while amylolytic activity does not vary significantly with increasing water hardness.

Heterocycles 48. Synthesis, Characterization and Biological Evaluation of Imidazo[2,1-b][1,3,4]Thiadiazole Derivatives as Anti-Inflammatory Agents

Non-steroidal anti-inflammatory drugs (NSAIDs) are an important pharmacological class of drugs used for the treatment of inflammatory diseases. They are also characterized by severe side effects, such as gastrointestinal damage, increased cardiovascular risk and renal function abnormalities. In order to synthesize new anti-inflammatory and analgesic compounds with a safer profile of side effects, a series of 2,6-diaryl-imidazo[2,1-b][1,3,4]thiadiazole derivatives 5a⁻l were synthesized and evaluated in vivo for their anti-inflammatory and analgesic activities in carrageenan-induced rat paw edema. Among all compounds, 5c showed better anti-inflammatory activity compared to diclofenac, the standard drug, and compounds 5g, 5i, 5j presented a comparable antinociceptive activity to diclofenac. None of the compounds showed ulcerogenic activity. Molecular docking studies were carried out to investigate the theoretical bond interactions between the compounds and target, the cyclooxygenases (COX-1/COX-2). The compound 5c exhibited a higher inhibition of COX-2 compared to diclofenac.

Antibacterial Activities of Spruce Bark (Picea abies L.) Extract and Its Components Against Human Pathogens

Spruce is a used material in the wood industry and bark is regarded as a by-product. The aim of this study was to provide information about natural bioactive compounds from spruce (Picea abies L.) bark with potential therapeutic applications such as antibacterial activity against human pathogens. Spruce bark extract was obtained by the conventional aqueous extraction (EAM), and second with ultrasounds (USM). It was determined the total polyphenols by spectrophotometric methods and individual polyphenols by high-performance liquid chromatography (HPLC). For the determination of minimum inhibitory concentration was used microdilution technique. The following strains were tested: Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The yield of extracted polyphenols in the case of spruce bark extract was of 33.8mg gallic acid/gfor EAM and 28.73 mg gallic acid/g for USM. The compounds identified in samples, by HPLC, were vanillic acid and taxifolin.It was found that both extracts have antibacterial capacity for all bacteria tested. The antibacterial effect of both extracts was stronger against Gram positive cocci compared with Gram negative bacilli.Antimicrobial spectra and activities of the fractions and pure isolated compounds from the spruce bark, can be suggested the use of spruce bark in pharmaceutical preparations and as well as a food preservative.

Essential Guide of Analysis Methods Applied to Silver Complexes with Antibacterial Quinolones

To describe the chemical structure and characterize physico-chemical properties of organometallic complexes it is necessary to use a complex set of analysis methods. Thus, this review has been compiled as a relevant guide which includes the most commonly used methods of analysis in the study of silver complexes with antibacterial quinolones, compounds with promising biological potential. This selection of analysis methods puts on balance the obtained data and the accessibility of the experimental approach. The steps to follow in order to obtain reliable structural information about organometallic complexes of silver, particularly the silver complexes of antibacterial quinolones, are established and presented in the review.

Vaccinium Extracts as Modulators in Experimental Type 1 Diabetes

Antihyperglycemic effects of four extracts obtained from leaves and fruits of Vaccinium myrtillus and Vaccinium corymbosum were assessed in diabetic rats. In addition, the effects of extracts on diabetic-related complications such as the development of diabetic cataract and oxidative stress were evaluated. Type 1 diabetes was induced with a single dose of streptozotocin in Wistar rats. The rats were randomly divided into seven equal groups: NC-normal control, DC-diabetic control, PC-positive control treated with metformin, VML-received V. myrtillus leaf extract, VMLF-received VML and fruit extract, VCL-received V. corymbosum leaf extract, and VCLF-received VCL and fruit extract. Body weight and glucose levels were monitored every second week. After 8 weeks of treatment, serum glucose, insulin, and malondialdehyde were measured. Lenses were removed after sacrifice and eight lenses from each group were randomly selected for evaluation of cataract development. A decrease in body weight was observed in all diabetic groups in the first weeks. In the VML group, no significant decrease was observed. Glucose levels during the experiment were high in DC, PC, and VCL groups, with no improvement during the 8 weeks. In VML, VMLF, and VCLF groups, a decrease in blood glucose levels was observed. Similar results regarding serum insulin and glucose levels at the end of the experiment were observed within groups. V. myrtillus extracts prevented the development of cataract compared with the DC group (P < .05).

Concomitant Quantification of Caffeine, Cotinine and N-methyl Uric Acid in Urine. Applications for athlete monitoring and pharmacological screening

Simultaneous determination of caffeine, cotinine, and 1N-methyluric acid in urine has numerous applications in determining patterns of use by athletes, according to the World Anti-Doping Agency (WADA) which includes these substances on the Monitoring List. The method can provide information on the enzyme-inducing activity on CYP1A2 of polycyclic aromatic hydrocarbons from cigarette smoke. Urine samples from 30 people (15 smokers and 15 non-smokers) were sampled 6 hours after having consumed a beverage with a total caffeine content of 200 mg. A HPLC with UV detection method was used which allowed concomitant determination of the three analytes. The results obtained show different values of caffeine urine concentrations (6.47 � 3.63 mM / L in smokers vs 10.09 � 5.68 in non-smokers, p [0.05) and a higher elimination of N1-methyluric acid by over 50% in smokers (identifiable due to the presence of cotinine, the main metabolite of nicotine).

The Role of Clindamycin Phosphate Associated with Adapalene in Three Semisolid Formulations Developed for Topical Acne Treatment

Despite the fact that in mild-to moderate acne vulgaris the standard first-line therapy is the topical treatment with fixed combinations of antimicrobial agents and retinoids, the skin type and the skin barrier function should be taken into account when formulating a topical product. The aim of this study was the comparison of three new semisolid formulations developed for topical application by evaluation of their rheological behavior, as well as the evaluation of in vitro percutaneous diffusion through human epidermis membrane of the pharmaceutical ingredients. Clindamycin phosphate and adapalene were incorporated in three different topical bases, an HPLC method for the determination of their content in the new formulations being developed and validated. A higher concentration of drugs was released from the two gel systems (hydroxypropylmethylcellulose 2.5% -F1 and hydroxyethylcellulose 3% -F2) than from the oil-in-water cream (F3) at pH 7.4, whereas at pH 5.5 the drugs were released in higher amounts from the formulation F3. Following the rheological behavoir associated with the penetrability through the human epidermis membrane, our study results suggest that F1 and F2 could be appropriate in treating acne lesions in patients with oily skin and unaffected skin barrier function. In contrast, the oil-in-water cream (F3), due to its possible emolient effect and its higher penetrability at pH 5.5 than gel vehicles, may be indicated for patients with dry and sensitive skin associated with an altered skin barrier.

Research Article. The Influence of Some Parameters on Chiral Separation of Ibuprofen by High-Performance Liquid Chromatography and Capillary Electrophoresis

Objective: The aim of the study was to compare the influence of mobile phase composition and temperature on chiral separation of racemic ibuprofen by capillary electrophoresis and high performance liquid chromatography with UV detection. Materials and methods: Racemic ibuprofen was analysed on a chiral OVM column with an HPLC system 1100 Agilent Technologies, under isocratic elution, by using potassium dihydrogen phosphate 20 mM and ethanol in mobile phase. The flow rate was set at 1 mL/min, UV detector at 220 nm and different column temperatures were tested. For electrophoresis separation an Agilent CE G1600AX Capillary Electrophoresis System system, with UV detection, was used. The electrophoresis analysis was performed at different pH values and temperatures, with phosphate buffer 25 mM and methyl-β-cyclodextrin as chiral selector. Results: The chromatograhic analysis reveals a high influence of mobile phase pH on ibuprofen enantiomers separation. An elution with a mixture of potassium dihydrogen phosphate 20 mM pH=3 and ethanol, at 25°C, allowed enantiomers separation with good resolution in less than 8 min. Conclusions: The proposed HPLC method proved suitable for the separation of ibuprofen enantiomers with a good resolution, but the capillary electrophoresis tested parameters did not allow chiral discrimination.

HPLC Enantioseparation of β-Blockers on Ovomucoid Stationary Phase†

The purpose of this study was to separate single and multiple pairs of six β-blockers enantiomers by high performance liquid chromatography on ovomucoid (OM) column in optimal conditions. The separation was performed isocratically or in gradient elution at 25°C, flow rate of 1 mL/min and 220 nm. The mobile phase consisted of phosphate buffer/acetonitrile or methanol. The effect of the organic modifier, the influence of pH and the percentage of the aqueous phase on resolution were investigated. The elution order of propranolol (PRP) enantiomers was established as well as the detection and quantification limits. The results show that OM was suitable for enantiomeric separation of the nonselective β-blockers carvedilol, PRP, pindolol and oxprenolol, and not for the two β-1 selective blockers, atenolol and metoprolol. A hypothesis regarding a possible correlation between structure-pharmacological activity-chromatographic behavior is proposed.

A New Silver Complex with Ofloxacin – Preliminary Study

Objective: Silver complexes of antibacterial quinolones have the potential advantage of combining the antibacterial activity of silver and fluoroquinolones. The objective of our study was the preparation and the preliminary physico-chemical characterization of a silver complex with ofloxacin.

Methods: To achieve our goals several spectroscopic methods (ultraviolet spectrophotometry, mass spectrometry, and Fourier transform infrared spectroscopy) and thermal methods (differential scanning calorimetry and thermogravimetric analysis) were used in order to elucidate the chemical structure of the complex.

Results: Using mass spectrometry we established the stoichiometric ratio silver:ofloxacin as 1:2. Experimental data suggest a particular coordination for ofloxacin, as a monodentate ligand, in the formation of a complex with silver, through the nitrogen atom from the methyl-piperazine cycle.

Conclusions: The obtained complex has a chemical structure likely [Ag(Ofloxacin)2]NO3, requiring evaluation through other physico-chemical methods.

Internal Structure Quality Control of Solid Pharmaceuticals. A Comparative Study

Objective: The aim of the study was a comparative investigation by spectral and thermal analysis in order to asses a number of characteristics of different varieties ofrawmaterials of ursodeoxycholic acid and ibuprofen. The different dissolution behavior of two ursodeoxycholic acid pharmaceutical product by crystallinity pattern was investigated. Methods: Raw materials of ursodeoxycholic acid and ibuprofen were used. IR spectroscopy, differential scanning calorimetry and X-Ray Diffraction Analysis were applied. Results: The results show no crystallinitydifferences for different batches of the tested drugs. No solid solid transition was proved during sample preparation for transmission IR analysis. Conclusions: A combination of two more affordabletests by IR spectrometry and differential scanning calorimetry lead to the same results as X-Ray diffraction analysis for crystallinity similarity assessment of the studied substances. The dissolution differences of test drugs were not related to the polymorphism of the raw materials.

Heterocycles 21. Reaction of 2-phenyl-thiazol-4-carbaldehyde with 2-bromoacetophenone

The condensation reaction of 2-phenyl-thiazol-4-carbaldehyde with 2-bromoacetophenone was performed in basic catalysis, resulting in a mixture of 2,3-epoxy-1-phenyl-3-(2-phenyl-thiazol-4-yl)-propan-1-one (1), 1-phenyl-3-(2-phenyl-thiazol-4-yl)-propane-1,2-dione (2) and 2-phenyl-4,5-bis-(2-phenyl-thiazol-4-yl)-3-hydroxy-furane (4). The isolated solids were structurally investigated by spectroscopic methods, i.e. infrared spectroscopy, mass spectrometry and NMR. In solution the dicarbonylic derivative 2 undergoes a tautomeric process, resulting in the enol 2-hydroxy-1-phenyl-3-(2-phenyl-thiazol-4-yl)-prop-2-en-1-one 3. Compounds 3 and 4 were transformed in the corresponding acetyl derivatives 5 and 6, respectively, by reacting them with acetic anhydride. For the furane 4 the single crystal X-ray diffraction structure was determined.

The Influence of Some Factors on Spirolactone Stability in Solution

The influence of some factors on spironolactone stability in solution was studied, by applying high-performance liquid chromatography, as a part of a pharmaceutical preformulation study in order to obtain a spironolactone solution for alopecia treatment. Solutions of 1 mg/ml spironolactone in aqueous ethanolic solution 1 : 1 and in 20 mM cyclodextrines solutions (b-, hydroxi-b- and methyl-b-cyclodextrine) was used, maintained at 8 and 22 �C, protected from light and after UV irradiation at 254 nm. The main degradation products were 7a-thiospirolactone and canrenone. The most stable solutions were the alcoholic ones and with methyl-beta-cyclodextrine, but the simultaneous action of temperature and UV irradiation allowed degradation processes after one hour of exposure, more aggressive in the presence of methyl-beta-cyclodextrine. In conclusion, for alopecia treatment with spironolactone a 1 mg/mL ethanolic solution could be used and it is recommendable the protection of treated zone.

[Stability of some medicinal solutions with captopril]

The aim of the study was to investigate the stability of some oral liquid formulations containing 1 mg/ml captopril.

MATERIAL AND METHOD

The oral solutions were prepared using captopril substance, keeping the formulation as simple as possible to avoid potentially undesirable excipients. Samples were stored for 39 days below 8 degrees C and at 22 +/- 3 degrees C and analysed for physical, chemical and microbiological stability.

RESULTS

The formulations with ascorbic acid are stable for seven days either at 8 and 22 degrees C and could be prepared in hospital pharmacy as a more safely alternative to children terapy with tablets powders.

New method for determination of dydrogesterone in human plasma for therapeutic drug monitoring in gynecological disorders

A new simple, sensitive and selective liquid chromatography coupled with mass spectrometry (LC/MS) method for quantification of dydrogesterone in human plasma was validated.

MATERIAL AND METHOD

The analytes was eluted in 1.3 minutes on a reversed phase column (Zorbax SB-C18, 100 mm x 3.0 mm I.D., 3.5 microm) under isocratic conditions using a mobile phase of a 20 : 80 (v/v) mixture of ammonium acetate 1 mM and acetonitrile. The flow rate was 1 mL/min at the column temperature of 35 degrees C. The detection of the analyte was in MS/ MS mode using an atmospheric pressure chemical ionization source (APCI+, m/z 313 > m/z 295). The sample preparation was very simple and rapid and consisted in plasma protein precipitation from 0.2 mL plasma using 0.6 mL methanol.

RESULTS

Calibration curves were generated over the range of 5-150 ng/mL with values for coefficient of determination greater than 0.997 and by using a weighted (1/y) linear regression. The values of precision and accuracy were less than 12.5% and 7.5%, respectively, both for within- and between-run analysis. The mean recovery of the analyte was 99.8%. This is the first reported method for analysis dydrogesterone in human plasma that uses protein precipitation as sample processing procedure. The validated LC/MS method could be applied for determination of dydrogesterone in human plasma for therapeutic drug monitoring in gynecological disorders.

[Physico-chemical characterisation of Zn-flavonols complexes]

The aim of flavonols complexation is to improve their specific activity.

MATERIAL AND METHOD

The flavonols sources were Morus alba L. and Morus nigra L., zinc being the biological active ion. Physico-chemical characterization was made by thin-layer chromatography, UV-VIS spectrophotometry, IR spectrometry and polarography.

RESULTS

The complexes results were within acceptability limits, but their obtaining is economically inefficient.

New validated method for piracetam HPLC determination in human plasma

The new method for HPLC determination of piracetam in human plasma was developed and validated by a new approach. The simple determination by UV detection was performed on supernatant, obtained from plasma, after proteins precipitation with perchloric acid. The chromatographic separation of piracetam under a gradient elution was achieved at room temperature with a RP-18 LiChroSpher 100 column and aqueous mobile phase containing acetonitrile and methanol. The quantitative determination of piracetam was performed at 200 nm with a lower limit of quantification LLQ=2 microg/ml. For this limit, the calculated values of the coefficient of variation and difference between mean and the nominal concentration are CV%=9.7 and bias%=0.9 for the intra-day assay, and CV%=19.1 and bias%=-7.45 for the between-days assay. For precision, the range was CV%=1.8/11.6 in the intra-day and between-days assay, and for accuracy, the range was bias%=2.3/14.9 in the intra-day and between-days assay. In addition, the stability of piracetam in different conditions was verified. Piracetam proved to be stable in plasma during 4 weeks at -20 degrees C and for 36 h at 20 degrees C in the supernatant after protein precipitation. The new proposed method was used for a bioequivalence study of two medicines containing 800 mg piracetam.

Determination of loratadine and its active metabolite in human plasma by high-performance liquid chromatography with mass spectrometry detection

A new sensitive and selective liquid chromatography coupled with mass spectrometry (LC/MS/MS) method for quantification of loratadine (LOR) and its active metabolite descarboethoxyloratadine (DSL) in human plasma was validated. After addition of the internal standard, metoclopramide, the human plasma samples (0.3 ml) were precipitated using acetonitrile (0.75 ml) and the centrifuged supernatants were partially evaporated under nitrogen at 37 degrees C at approximately 0.3 ml volume. The LOR, DSL and internal standard were separated on a reversed phase column (Zorbax SB-C18, 100 mmx3.0 mm i.d., 3.5 microm) under isocratic conditions using a mobile phase of an 8:92(v/v) mixture of acetonitrile and 0.4% (v/v) formic acid in water. The flow rate was 1 ml/min and the column temperature 45 degrees C. The detection of LOR, DSL and internal standard was in MRM mode using an ion trap mass spectrometer with electrospray positive ionisation. The ion transitions were monitored as follows: 383-->337 for LOR, 311-->(259+294+282) for DSL and 300-->226.8 for internal standard. Calibration curves were generated over the range of 0.52-52.3 ng/ml for both LOR and DSL with values for coefficient of determination greater than 0.994 by using a weighted (1/y) quadratic regression. The lower limits of quantification were established at 0.52 ng/ml LOR and DSL, respectively, with an accuracy and precision less than 20%. Both analytes demonstrated good short-term, long-term, post-preparative and freeze-thaw stability. Besides its simplicity, the sample treatment allows obtaining a very good recovery of both analytes, around 100%. The validated LC/MS/MS method has been applied to a pharmacokinetic study of loratadine tablets on healthy volunteers.

New HPLC–MS method for quantitative determination of apovincaminic acid in human plasma

A fast and sensitive HPLC-MS method for the quantification of apovincaminic acid, a vinpocetine metabolite, in human plasma has been developed and validated. After protein precipitation with methanol, 10 mL of supernatant was injected at 45 degrees C onto a Zorbax SB-C18 column. Elution was performed in less than three minutes with water containing 0.2% formic acid and acetonitrile (80:20) at 0.75 mL/min. A linearity domain between 4 and 240 ng/mL and a limit of quantification of 4 ng/mL apovincaminic acid were established by monitoring the signal corresponding to m/z = 323. Accuracy and precision were less than 5.2% for within-run assay and 10% for between-run assay. The method was successfully applied in a bioequivalence study of two pharmaceutical products containing 5 mg vinpocetine.

[Qualitative determination of flavonoids and phenol-carboxylic acids of indigene Stachys species using HPLC method]

Indigene Stachys species have a high content in interesting compounds as iridoids, but also high quantities of flavonoids and phenol-carboxylic acids. These compounds present vasorelaxing effect on smooth vascular muscle interfering with metabolic degradation of nitric oxide pathways (inhibition of peroxynitrites formation) and by inhibition of phosphodiesterase. This work shows flavonoids spectrum of 3 Stachys species using HPLC methods. We identified quercetol, rutoside, miricetin and phenol-carboxylic acids (chlorogenic, caffeic and ferulic acids).

Validation of an HPLC method for the determination of ciprofloxacin in human plasma

A simple HPLC method with fluorescence detection of ciprofloxacin in human plasma was developed and validated. After protein precipitation, chromatographic separation of ciprofloxacin in plasma was achieved at 35 degrees C with a C18 column and acetonitrile-phosphate mixture, pH 3, as mobile phase. Quantitative determination was performed by fluorimetry after excitation at 278 nm. The method was specific and validated with a limit of quantification of 41 ng/ml. The intra- and inter-day coefficients of variation were between 0.5 and 6.6% and accuracy between -2.02 and 7.04%. Ciprofloxacin was stable in plasma for 40 days at -20 degrees C and after three freezing-thawing cycles. The method has been applied in a bioequivalence study of two formulation of 500 mg ciprofloxacin.

The study of codeine-gluthetimide pharmacokinetic interaction in rats

A high-performance liquid chromatographic (HPLC) assay with native fluorescence detection was developed for the simultaneous quantification of codeine and its two metabolites, morphine and morphine-3-glucuronide (M-3-G), in rat plasma. Solid-phase extraction was used to separate codeine and its metabolites from plasma constituents. Extraction efficiencies of codeine, morphine and M-3-G from rat plasma samples were 97, 92 and 93%, respectively. The chromatographic separation was performed using a reversed-phase C18 column and an elution gradient at ambient temperature. Using native fluorescence detection (excitation at 245 nm and emission at 345 nm), the detection limits of 50 ng/ml for morphine, 25 ng/ml for codeine and 20 ng/ml for M-3-G were obtained. The method had good precision, accuracy and linearity, and was applied to the study of glutethimide's influence on codeine metabolism in rat, following single doses of codeine-glutethimide association. The results confirmed the fact that glutethimide was responsible for a significant increase of morphine plasma levels and for their maintenance in time, concomitant with a significant decrease of M-3-G plasma levels, explained by the inhibition of morphine glucuronidation. In conclusion, glutethimide potentiates and prolongs the analgesic effect of codeine by a pharmacokinetic mechanism.

Characterization and lime treatment of olive mill wastewater

Seventeen olive mill wastewater (OMW) samples were characterized. For characterization of the samples, amount of total, fixed, volatile, suspended, volatile-suspended solids, COD, oil-grease, polyphenol, volatile phenol, nitrogen and reducing sugar were determined. Effects of lime treatment on the waste samples were investigated. Reduction of contents of the samples treated with the lime was described. The effect of the addition of lime on an artificial phenolic mixture was also examined.

High sensitivity to autoxidation in neonatal calf erythrocytes: possible mechanism of accelerated cell aging

The suspension viscosity, formation of methaemoglobin and production of malondialdehyde (MDA) associated with the non-enzymatic oxidation of polyunsaturated fatty acids during auto-oxidation conditions in vitro have been compared in erythrocytes from young calves (2, 4 and 6 weeks of age) and mature cattle. The autoxidation conditions were designed to simulate the oxidative stress to which neonatal erythrocytes are exposed in vivo. Characterisation of lipid peroxidation was also undertaken by a combination of lipid fluorescent measurements and quantification of the superoxide dismutase (SOD) activities of the erythrocytes. The results demonstrated that high SOD activities in the erythrocytes of the neonatal calf was insufficient to afford protection against the increased autoxidation of haemoglobin and subsequent accumulation of lipid peroxidation products. High levels of methaemoglobin formation and lipid peroxidation were able to provide an explanation for an observed reduction in rheological adaptability (increased suspension viscosity) and an accelerated aging of the neonatal cells under in vivo conditions.

[Effect of paracetamol on the acid hemolysis of erythrocytes, with special reference to the intracellular glutathione level]

The authors give account of their study concerning the effect of paracetamol on the acid haemolysis, and glutathione content of human erythrocytes. In vitro, paracetamol decreased intracellular glutathione content in a dose dependent manner. This may lead to an increased sensitivity of erythrocytes to the haemolytic effect of hydrochloric acid, what may explain the dose dependent decrease of time of haemolysis, presented in form of dynamic haemolysis curve. In vivo four hours following the oral intake of 500 mg paracetamol, although the intracellular glutathione content did not decrease significantly, shortening of the time of acid haemolysis could be demonstrated in more than half of the persons studied. No haemolysis was caused by the given dose of the drug.

The effect of silibinin (Legalon) on the the free radical scavenger mechanisms of human erythrocytes in vitro

The effect of Legalon was investigated parallel with that of Adriblastina (doxorubicin) and paracetamol on some parameters characterizing the free radical scavenger mechanisms of human erythrocytes in vitro and on the time of acid hemolysis performed in aggregometer. Observations suggest that Adriblastina enhances the lipid peroxidation of the membrane of red blood cells, while paracetamol causes significant depletion of intracellular glutathione level, thus decreasing the free radical eliminating capacity of the glutathione peroxidase system. Legalon on the other hand, is able to increase the activity of both superoxide dismutase and glutathione peroxidase, which may explain the protective effect of the drug against free radicals and also the stabilizing effect on the red blood cell membrane, shown by the increase of the time of full haemolysis.

[Auto-oxidation test for the determination of lipid peroxidation capacity of liver tissue homogenates of young and old mice]

The activity of superoxide dismutase (SOD) and the lipid-peroxidation capacity, i.e., the autoxidation of lipids during incubation at 37 degrees C for 3 h under aerobic conditions was measured in liver tissue homogenates of young (1.5-month-old) and old (24-month-old) inbred female Balb/c mice. The lipid peroxidation capacity was found to be significantly higher in young mice than in old ones. The pretreatment of young mice with allopurinol, a specific inhibitor of xanthine oxidase, remarkably decreased the lipid peroxidation capacity without any modification of SOD activity. SOD levels were equal in young and old mice. Our results suggest that the lipid peroxidation capacity of liver tissue depends, not only on the level of polyunsaturated fatty acids, but, in general, also on the state of a finely regulated counterbalance of pro- and antioxidant factors. The autoxidation test seems to be a suitable in vitro method for measuring the lipid peroxidation capacity of liver tissue.

Lipid peroxidation and superoxide dismutase activity in muscle and erythrocytes in adult muscular dystrophies and neurogenic atrophies

Lipid peroxidation (LP) and superoxide dismutase (SOD) activity were determined in erythrocytes and skeletal muscle obtained from patients with limb-girdle and facioscapulohumeral muscular dystrophies, neurogenic atrophies and from age-matched control subjects. Neither lipid peroxidation nor SOD activity in erythrocytes of patients differed from control values. SOD activity and LP in muscle specimens were also normal in types of neurogenic atrophy. Lipid peroxidation in the muscle from patients with adult types of muscular dystrophy had a tendency to be increased. The values were widely scattered, the highest being obtained in the older patients with long duration of disease.