Injection Volume Research Articles

Determination of parabens and bisphenol A in sludge samples using hydrophobic deep eutectic solvents by gas chromatography coupled to mass spectrometry and sample introduction via pyrolizer

This study reports on the development and use of hydrophobic deep eutectic solvents (HDES) as environmentally-friendly solvents to address the demand for low-toxicity materials for analysts and the environment. The study involved the application of HDES in environmental matrices for extracting emerging contaminants. In this case, HDESs were used as extraction solvents in dispersive liquid–liquid microextraction (DLLME) to determine parabens and bisphenol A from sludge samples. Gas chromatography-mass spectrometry (GC–MS) featuring a pyrolizer was used for sample introduction. Chemometric tools were utilized to optimize analysis conditions, considering the sample introduction and DLLME parameters. HDESs were characterized using Fourier-Transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and thermogravimetric analysis (TG). Univariate and multivariate strategies were employed to determine the optimal experimental conditions. In this case, the injection volume was fixed as 20 µL, with a temperature of 320 °C and a pyrolizer duration time of 0.5 min. For DLLME, full factorial design permitted identification of the best condition of each experimental variable, including the salting-out effect, pH, volume of dispersing solvent, and volume of extraction solvent. Optimal conditions for DLLME in sludge samples were determined as 300 µL of HDES, 350 µL of ACN, pH = 10, and the addition of NaCl at 27 % m/v. Following optimization studies, a HDES was successfully applied as an extraction solvent to determine endocrine disruptors in sludge samples. Future work involves the analysis of additional sludge samples (both liquid and solid phases) using standard addition to quantify analytes using the developed methodology. The utilization of HDES within environmental samples facilitated the identification of emerging contaminants, aligning with the tenets of sustainable analytical chemistry. This was substantiated by applying the GREEnness Analytical (AGREE) evaluation metric system, yielding values of 0.72 and 0.76 for the employed methodology and sample preparation, respectively.

Chromatographic analysis of ponatinib and its impurities: method development, validation, and identification of new degradation product

BackgroundPonatinib, a third-generation tyrosine kinase inhibitor, is employed in the management of adult chronic myeloid leukemia. Nevertheless, the presence of process impurities and degradation impurities linked to ponatinib may potentially influence its effectiveness and safety. Therefore, the objective of this research was to establish a robust liquid chromatography method and systematically validate it for the detection of substances related to ponatinib.MethodsThe separation of ponatinib and its impurities was conducted using an Agilent 5HC-C18 chromatographic column (4.6 mm × 250 mm, 5 μm). The mobile phase A comprised a mixture of water and acetonitrile in a 9:1 ratio, with an aqueous solution of pH 2.4 containing 2 mM potassium dihydrogen phosphate and 0.4% triethylamine. Mobile phase B, consisting of acetonitrile, was eluted in a gradient fashion. The flow rate was set at 1.0 mL/min, detection wavelength at 250 nm, column temperature at 40°C, and injection volume at 10 μL.ResultsThe method demonstrated high specificity, sensitivity, solution stability, linearity, precision, accuracy, and robustness. Additionally, this research unveiled a novel compound, imp-B, generated via the oxidative degradation of ponatinib. The molecular structure of the newly discovered product was elucidated through the utilization of nuclear magnetic resonance (NMR) and high-resolution mass spectrometry (HRMS).ConclusionIn conclusion, the chromatographic method developed in this study has the potential to be utilized for the detection of ponatinib and its impurities, thereby offering significant insights for quality assessment in ponatinib research.

Delayed vascular occlusion following hyaluronic acid-based skin booster – A rare case report

Hyaluronic acid (HA) based skin boosters used for treating fine lines and for enhancing the quality of skin are quite popular as they help by drawing water under the dermis (hydrofilling effect), helping in prolonged hydration of the skin. They are also considered safe due to the superficial plane of injection and low volumes injected. The patient came to the clinic for skin hydration and rejuvenation treatment. After detailed discussion and informed consent, a non-animal origin HA-based skin booster with a concentration of 20 mg/mL was chosen for facial rejuvenation. As per protocol, 2 mL of the product was injected by micropuncture technique with the automated click technology, delivering 0.01 mL per point in the mid dermis all over the cheeks, chin, and forehead. The patient tolerated the procedure well and presented to us 48 hours post-injection with persisting redness and pain on the central forehead. The redness appeared to be in a triangular pattern, with the apex at the left eyebrow and the base toward the hairline. Diagnosis of vascular compromise was made, and the patient was immediately treated with pulsed doses of hyaluronidase. The entire area healed without any sequelae. We hereby report a rare case of delayed vascular occlusion following skin booster treatment, which was successfully managed by hyaluronidase treatment. Skin boosters are the most sought after treatments for skin hydration and are generally considered safe; this is the first case report with delayed vascular occlusion reported following skin booster injections. Because of the high risk associated with glabella and forehead areas for fillers, one should be mindful in this area even with the skin boosters.

Abstract 4137339: Application of PLGA-PEG-PLGA Thermosensitive Hydrogel Loaded with Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes and Ginsenoside Rb3 in the Treatment of Acute Myocardial Infarction

Background: Ginsenoside Rb3 (GSRb3) is a traditional Chinese medicine monomer. We aim to investigate the effects of GSRb3 on the proliferation of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) and the reparative effects of PLGA-PEG-PLGA thermosensitive hydrogel loaded with hiPSC-CMs and GSRb3 (NP GSRb3 @Gel+iCM) on myocardial infarction (MI). Methods: 1. Western Blot, RT-qPCR, cell immunofluorescence staining, and CCK-8 assays were employed to assess the proliferative effects of different concentrations of GSRb3 on neonatal mouse primary cardiomyocytes (NCMs) and hiPSC-CMs. 2. Transcriptomic gene sequencing technology was utilized to investigate the mRNA expression changes of hiPSC-CMs induced by GSRb3; The NP GSRb3 @Gel+iCM was injected into the left ventricular myocardium of the MI mice; the same volume injections of hiPSC-CMs (iCM group) and PLGA-PEG-PLGA thermosensitive hydrogel loaded with GSRb3 (NP GSRb3 @Gel group) served as control; Additionally, MI model group without additional treatment and sham group were established. 3. At 4 weeks post-MI, echocardiography, Sirius Red/Fast Green staining and immunofluorescence staining were utilized to evaluate the heart function, infarction size and survival rate of transplanted hiPSC-CMs. Results: GSRb3 inhibit the apoptosis of NCMs while promote proliferation of NCMs and hiPSC-CMs significantly. After 4 weeks of treatment, the engraftment rate of hiPSC-CMs in NP GSRb3 @Gel+iCM group (36.7%) was 4.8 times that of iCM group (7.7%); Compared to the MI group, NP GSRb3 @Gel group and iCM group, NP GSRb3 @Gel+iCM group showed significant improvement in cardiac function; The myocardial repair effect in NP GSRb3 @Gel+iCM group was significantly superior to NP GSRb3 @Gel group and iCM group, with a 47% reduction in infarct size compared to MI group, and further reduction in left ventricular anterior wall thickness compared to NP GSRb3 @Gel group and iCM group. Conclusion: GSRb3 promotes the proliferation of hiPSC-CMs both in vitro and in vivo. NP GSRb3 @Gel+iCM significantly increase the engraftment of hiPSC-CMs, promote angiogenesis, reduce infarction size, inhibit left ventricular remodeling and improve cardiac function.

A Micro-Flow Liquid Chromatography-Mass Spectrometry Method for the Quantification of Oxylipins in Volume-Limited Human Plasma.

Oxylipins are well-known lipid mediators in various inflammatory conditions. Their endogenous concentrations range from low picomolar to nanomolar, and there are growing demands to determine their concentrations in low-volume matrices for pathological studies, including blood, cerebrospinal fluids from animal disease models, infants, and microsampling devices. Most of the published quantification methods for comprehensive profiling of oxylipins still require more than 50µL plasma as a starting volume to detect these low levels. The aim of our study is to develop a sensitive and reliable method for the quantification of oxylipins in volume-limited human plasma samples. We established and validated a micro-liquid chromatography (LC)-mass spectrometry (MS)/MS method that requires only 5µL of human plasma for the determination of 66 oxylipins. The optimized micro-LC-MS/MS method utilized a flow rate of 4µL/min with a 0.3-mm inner diameter column. With an injection volume of 3µL, our method provides limits of detection in the range from 0.1 to 91.9pM, and limits of quantification range from 0.3 to 306.2pM. The sensitivity enhancement compared to conventional flow ranged from 1.4 to 180.7 times for 51 compounds depending on their physical-chemical properties. After validation, the method was applied to analyze 40 plasma samples from a healthy aging study to demonstrate robustness and sensitivity.

Eco-friendly RP-HPLC approach for simultaneously estimating the promising combination of pentoxifylline and simvastatin in therapeutic potential for breast cancer: Appraisal of greenness, whiteness, and Box–Behnken design

Abstract Breast cancer affects millions of women worldwide. This study explores the potential of combining pentoxifylline (PTX) and simvastatin (SIM) as a treatment for breast cancer. We aimed to develop six sustainability tools using green and white metrics to evaluate the environmental impact of reversed-phase high-performance liquid chromatography (RP-HPLC) methods for analyzing and separating PTX and SIM in their pure forms. The tools include analytical GREEnness, green analytical procedure index, Complexgreen analytical procedure index, analytical greenness metric for sample preparation, blue applicability grade index, and the RGB 12 algorithm. For the separation, we used a Novapack C8 column (15 × 0.46 cm, 5 µm) at 25°C. The injection volume was 5.0 µL, the wavelength was set to 210 nm, and the total runtime was 5 min. We identified optimal chromatographic conditions efficiently using the Box–Behnken design with minimal trials. We investigated the effects of three factors on retention time and resolution: acetonitrile ratio, pH, and flow rate. We used overlay plots with a 60:40 ratio (v/v) of acetonitrile and bi-distilled water to forecast the most effective mobile phase. The calibration curves for PTX and SIM showed a correlation value of over 0.999 within the range of 5–60 µg·mL−1. The recovery rates ranged from 99.9% to 100.2%, indicating high accuracy. Our RP-HPLC technique proves to be reliable and efficient for the simultaneous estimation of multiple anticancer drugs. We evaluated the environmental sustainability of this approach using green and white metrics, and the recommended method has been thoroughly validated according to International Council for Harmonisation guidelines, making it highly reliable for analyzing new formulations.

Research on the stimulation mechanism of well shut-in imbibition and parameter optimization during fracturing-flooding

ABSTRACT In the development of low-permeability tight oil reservoirs, fracturing-flooding technology, with its dual advantages of “fracture creation and energy replenishment, and displacement by imbibition,” effectively addresses challenges such as poor water injection and low oil recovery. However, the mechanism of oil-water migration within the reservoir and the enhanced oil recovery during the shut-in imbibition process remain unclear, and the construction parameters are primarily based on empirical data. In this study, focusing on the Y block in the Bohai Bay Basin, eastern China, we conducted dynamic imbibition experiments and utilized nuclear magnetic resonance (NMR) technology to analyze the key factors influencing imbibition-driven oil displacement and the microscopic oil-water migration mechanisms within the pore space. Numerical simulation was then employed to optimize the construction parameters for fracturing-flooding operations. The results indicate that displacement and imbibition primarily occur in medium-sized pores, while the poor connectivity of micro- and small-sized pores leads to suboptimal effects. The shut-in process provides favorable conditions for imbibition displacement, allowing oil in small and medium pores to be further displaced into fractures. The main factors affecting imbibition efficiency include core permeability (optimal range: 1.5 mD to 4 mD), fracture length (approximately 2/3 of the core length), fracturing-flooding fluid concentration (optimal around 0.2%), and shut-in time (optimal range: 24 to 48 hours). Based on production capacity simulations, the optimal construction parameters for the Y block include an injection rate of 1152 to 1440 m3/min, a total injection volume of 20,000 to 25,000 m3, and a shut-in time of 30 to 45 days. The application of these optimized parameters resulted in an increase in the average daily oil production in the Y block from 4.4 tons to 7.7 tons, demonstrating a significant enhancement in reservoir productivity and oil recovery.

BOX-BEHNKEN DESIGN ASSISTED ECO-FRIENDLY RP-HPLC-PDA METHOD FOR THE QUANTIFICATION OF PACLITAXEL: APPLICATION TO EVALUATE THE SOLUBILITY OF PACLITAXEL-CYCLODEXTRIN COMPLEX

Objective: Paclitaxel (PTX) is one of the oldest chemotherapeutic agents for cancer treatment. However, PTX is a class IV drug under the Biopharmaceutical Classification System (BCS), and its oral administration is restricted due to its low bioavailability. Complexing PTX with Beta-Cyclodextrin (β-CD) is an option to overcome the low solubility and bioavailability. This study aims to optimize and develop an RP-HPLC analytical method for quantifying PTX from the fabricated β-CD complex. Methods: The HPLC settings were optimized using Design-of-Experiments (DOE) software. The independent variables for the optimization process were buffer ratio, buffer pH, flow rate, and injection volume. The responses were Retention Time (RT), peak area, Tailing Factor (TF), and number of Theoretical Plates (TP) of PTX. The validated method was then used to measure the % entrapment from the PTX-β-CD complex. Results: The developed and optimized RP-HPLC method was validated as per International Council for Harmonisation (ICH) Q2 (R1) guidelines. The developed method showed linearity R2 = 0.999 with a 0.5-20 µg/ml range. The Limit of Detection (LOD) and Limit of Quantification (LOQ) were 95 and 125 ng/ml, respectively. The accuracy and precision for the developed method came under the acceptance criteria. The developed method was used to evaluate the enhancement of solubility of the prepared PTX-β-CD complex. The method was also used in the evaluation of % drug loading, % drug release and stability of the PTX-β-CD complex. The study clearly showed that the solubility of PTX increased from 0 to 1.14±0.53 µg/ml at pH 1.2 and 0 to 3.18±0.61 µg/ml at pH 6.8, respectively. The PTX-β-CD complex showed 73±3.75% drug release in 120 min at pH 1.2 and 87±3.51% at pH 6.8. The developed RP-HPLC method was found to be eco-friendly as per the Analytical Greenness (AGREE) metric approach and software analysis. Conclusion: An eco-friendly RP-HPLC analytical method was successfully developed and optimized for the quantification of PTX from the PTX-β-CD complex.

Postoperative analgesic effect of lumbar erector spinae plane block for developmental hip dysplasia surgery: a randomized controlled double-blind study.

Open surgery for developmental dysplasia of the hip (DDH) may cause severe pain due to tenotomies and pelvic-femoral osteotomies. This study aims to evaluate the analgesic effect of ultrasound-guided Lumbar Erector Spina Plane (L-ESP) Block in pediatric patients undergoing DDH surgery. Sixty children scheduled for DDH surgery were randomly assigned into two groups. Group I (n = 30) received L-ESP with 0.5 mL/kg of 0.25% bupivacaine before surgery. In contrast, Group II (n = 30), as the control group, received the same volume of saline injection. Identical postoperative analgesia protocol was adjusted for both groups. Parental satisfaction, pain levels, ibuprofen, and opioid consumption were recorded. Pain levels were evaluated with the FLACC (Face, Legs, Activity, Crying, Consolability) scale. FLACC scores at the first 24th hours were lower in the L-ESP group than the control group (p < 0.001). Rescue opioid utilization was higher in the control group (15/26) than in the L-ESP group (2/29) (p < 0.001). The consumption of ibuprofen was higher in the control group than in the L-ESP group in the ward (24/26 vs. 3/29, p < 0.001, respectively). Parental satisfaction was superior in the L-ESP group (p = 0.024). To provide postoperative analgesia for DDH surgery, ultrasound-guided L-ESP may be an effective and alternative regional anesthetic technique.

Clinical Outcomes and Safety Profile of a Dextranomer-Hyaluronic Acid Hybrid Filler: A Case Series Analysis.

The demand for aesthetic treatments targeting the middle and lower face is on the rise, especially because of changes in appearance associated with aging. This study aimed to assess the use of a hybrid filler for sculpting and contouring of the chin, jaw, and malar region. A retrospective analysis was performed on patients who underwent jaw and chin contouring and cheek augmentation using a hybrid filler (hyaluronic acid and dextranomer). The evaluation focused on the naturalness of appearance, enhancement in volume, and the durability of the results, employing a 5-point scale. Both patient satisfaction and physician evaluations were measured using the Likert scale and the Global Aesthetic Improvement Scale (GAIS), respectively. Follow-up with patients extended up to 6 months after treatment, during which any treatment-related adverse events (AEs) were meticulously recorded and analyzed. Nineteen patients participated in the study, receiving an average injection volume of 2.4 ± 0.9 mL to attain the desired outcomes. The evaluation of natural appearance, volumizing effects, and durability at the analyzed time point consistently scored above 4. All 19 patients' aesthetic improvement was evaluated as "very much improved" and "much improved", at the GAIS score. All patients report improvement in their appearance, with 89.5% rating it as "very much improved" or "much improved" on the Likert scale. Only expected AEs such as mild pain and lower swelling were registered. The hybrid filler proved effective and safe for facial contouring, with significant patient satisfaction and minimal adverse effects.

Stability indicating RP-HPLC method development and validation for quantification of impurities in gonadotropin-releasing hormone (Elagolix): Robustness study by quality by design.

The purpose of this research was to establish and validate a reverse phase HPLC method for the determination of Elagolix impurities in pharmaceutical dosage form. Mobile phase A, consisting of 10mM sodium dihydrogen phosphate (pH6.0) and acetonitrile in a 95:5v/v ratio, and mobile phase B, containing 85:10:5v/v/v of acetonitrile, Milli-Q water, and methanol, were used to achieve the method's specificity in the analytical column Kromasil 100-C18 (250 mm × 4.6mm, 5μm). The gradient program includes (%B/Time [min]: 36/0, 36/10, 38/15, 85/55, 85/65, 36/67, and 36/75). The flow rate is 0.8mL/min. The overall run duration is 75.0min, the injection volume is 10.0μL, and the detection is at 210 nm in UV. The samples were subjected to hydrolysis, oxidation, and heat conditions in order to facilitate their forced degradation. The procedure was validated and determined with the standards of ICH guidelines. From the LOQ to a concentration level of 200%, the linearity of the technique was ascertained. An accuracy range of LOQ to 150% was established for the method, and the average recovery was acceptable. Design of experiments, part of the quality by design idea, was used to prove the method's reliability.

Quality by Design Approach Driven Development and Validation of Reverse Phase‐High‐Performance Liquid Chromatography Methodology for Dual Quantification of Aspirin and Rivaroxaban

ABSTRACTClinical trials have shown that combining a modest dose of Rivaroxaban (RIV) with Aspirin (ASP) is more effective than ASP alone in reducing cardiovascular mortality, myocardial infarction, and stroke. A high‐performance liquid chromatography method developed using Quality by Design (QbD) effectively estimates ASP and RIV for routine pharmaceutical analysis. The Plackett‐Burman design assessed key factors including organic phase volume, mobile phase pH, flow rate, temperature, and injection volume using an Ishikawa fish‐bone diagram for risk assessment. These parameters were then optimized via Box‐Behnken design in 15 trials. The method meets the International Council For Harmonization standards with a mobile phase ratio of 45:55 (v/v) acetonitrile: buffer (pH 3, adjusted with orthophosphoric acid), a flow rate of 1 mL/min, a column temperature of 30°C, and an injection volume of 20 µL. A Phenomenex Luna C18 column (250 × 4.6 mm, 5 µm particle size) with detection at 251 nm ultra‐violet wavelength. The retention times of 4.54 min for ASP and 5.81 min for RIV were obtained. Validation confirmed linear ranges: 40–200 µg/mL for ASP and 2–10 µg/mL for RIV, with excellent recovery rates (ASP: 99.30%–101.9%; RIV: 98.52%–101.84%). Developed using QbD principles, the method proved specific, accurate, precise, sensitive, and robust for routine quality control of both compounds in pharmaceutical formulations.

A new method development and validation for simultaneous estimation of ramipril and telmisartan by RP-HPLC method in combined dosage form

The present research work was development and validation of new RP-HPLC method for simultaneous estimation of Ramipril and Telmisartan in combined dosage form. In simultaneous RP-HPLC method development, Waters 2695 Separations Module with PDA Detector and column used is C8 SB ZORBAX (150 X 4.6mm) column with 3.5-micron particle size. Injection volume of 10 µL is injected and eluted with the mobile phase selected after optimization was Phosphate buffer and Acetonitrile in the ratio of 70:30 was found to be ideal. The optimized flow rate was at 1.0 mL/min. Detection was carried out at 230 nm. This system produced symmetric peak shape, good resolution and reasonable retention times of Ramipril and Telmisartan were found to be 2.275 and 4.261 minutes respectively. The Ramipril and Telmisartan showed linearity in the range of 20-60 µg/mL and 160-480 µg/mL respectively. The %RSD values for precision was found to be within the acceptable limit, which revealed that the developed method was precise. The developed method was found to be robust and the %RSD value for percentage recovery of Ramipril and Telmisartan was found to be within the acceptance criteria. The results indicate satisfactory accuracy of method for simultaneous estimation of the Ramipril and Telmisartan.

A novel RP-HPLC method for the simultaneous quantification of azithromycin and dexamethasone in marketed ophthalmic drops

A straightforward, precise, accurate, specific, and sensitive RP-HPLC technique has been established for the quantification of Azithromycin Dihydrate and Dexamethasone Sodium Phosphate in their commercial formulation. The wavelength maxima for Azithromycin and Dexamethasone were considered to be 215 nm for estimation. In RP-HPLC separations were carried out on a Zorbax SB C18 column (250mm X 4.6mm, 5 μm) and mobile phase consisting of Acetonitrile: Monobasic Potassium Phosphate (KH2PO4) buffer in the proportion of 75:25 v/v and pH of the buffer was adjusted to 5.5 with OPA. The estimation was carried out at 215 nm using UV detector keeping the flow rate of 1.2 ml/min and injection volume of 50 μl. The current method demonstrates good linearity over the range of 20 - 120 μg/ml and 2 - 12 μg/ml for Azithromycin and Dexamethasone respectively. No interference of excipients was found during estimation. The recommended techniques were verified and determined to be specific, accurate, and exact. The approaches were effectively used for the concurrent quantification of both medicines in pharmaceutical formulations, making them suitable for regular quality control examination.

Evaluating the potential of hydrophilic interaction liquid chromatography for collagen peptide mapping analysis

This study presents a systematic approach for developing an innovative hydrophilic interaction liquid chromatography (HILIC) method for collagen peptide mapping analysis. The predominant post-translational modification (PTM) of collagen, proline hydroxylation, introduces polar hydroxyl groups throughout the collagen sequence, making HILIC a promising alternative to classical reversed-phase liquid chromatography (RPLC) approaches. This study employs sixteen model peptides, selected from in silico predicted tryptic peptides with zero missed cleavages and representing diverse physicochemical properties and structural motifs of collagen. The peptides were used as standards to conduct detailed chromatographic evaluation. Various HILIC stationary phases and mobile phases were systematically examined to identify optimal separation conditions for collagen peptides, contributing to a better understanding of peptide behavior in HILIC. The study also explores the effects of sample diluent and injection mode, comparing classical injection with the Performance Optimizing Injection Sequence (POISe), to determine their impact on HILIC performance. Introducing a plug of weak solvent (acetonitrile) prior to sample injection, effectively mitigates the mismatch in eluent strength between the fully aqueous sample diluent (resulting from tryptic digestion) and the mobile phase, addressing issues of peak distortion. Different injection volumes (from 0.5 to 8 µL) and acetonitrile ratios (1:1, 1:2, 1:5 and 1:10) were tested to optimize sample injection and increase sensitivity of collagen tryptic peptides.Following method optimization, HILIC was coupled with mass spectrometry (MS) to evaluate its effectiveness in analyzing collagen-digested samples. This evaluation included the assessment of peptide sequence coverage and the method ability to identify hydroxylation patterns, thereby demonstrating its potential for detailed peptide analysis.

Assessment of miligram(Mg) content of some notable analgesics used by residents of Maiduguri Metropolis: evidence from high performance liquid chromatographic technique

Diclofenac sodium and paracetamol are Over the counter (OTC) medications used as analgesic and antipyretic agents to relieve pains, fever and headaches. The aim of this work was determine the mg content of paracetamol and diclofenac sodium in selected samples across the Maiduguri metropolis using High Performance liquid chromatography (HPLC) method. For paracetamol samples an intersil ODS-3V column (150 mm × 4.6 mm; 5 μm pore size) was used at the temperature of 35oC the mobile phase was methanol: water (20:80) using isocratic elution at the flow rate of 2 mL/min, injection volume of 10 μL and a diode array detector. For diclofenac sodium samples, the chromatographic conditions were the same except the mobile phase which was methanol: water (63:37), flow rate of 0.8 mL min, injection volume of 20 μL and column temperature was set at 30 oC. A total of 45 samples were analysed; which comprised of paracetamol tablet, paracetamol syrup and diclofenac sodium tablet which were randomly selected from three different sources; hospital pharmacy, community pharmacy and drug patent stores. The percentage mg content for paracetamol tablets ranged from 48 to 83 % while that of the paracetamol syrups ranged from 72 to 120 % and finally diclofenac sodium tablets ranged from 73 to 174 %. Adopting the United State Pharmacopoeia (USP) as reference for assessment tool, it was observed that all the paracetamol tablet samples failed, 4 out of 15 paracetamol syrup samples failed, and 11 out of 15 diclofenac sodium tablet samples failed. There was statistical significance (p&lt; 0.05) between class of drug and percentage mg content but there was no significance (p&lt; 0.05) between source of drug and percentage constituent. HPLC technique was used successfully for quantitative determination of paracetamol and diclofenac sodium dosage forms.

A Simple HPLC-DAD Method for the Therapeutic Monitoring of Clozapine and Related Metabolites in Human Plasma and Urine Samples.

Clozapine and its metabolites require close therapeutic monitoring (TDM) in patients due to poor correlation between the administrated doses and resulting plasma concentrations, the narrow therapeutic interval, high inter-individual variability, and the risk of serious side effects once toxic levels are exceeded. The aim of the study was to develop a simple (relatively cheap) LC-UV method for the quantification of clozapine and its metabolites in plasma and urine samples. For sample preparation, liquid-liquid extraction (LLE) in n-octanol was more efficient and less limiting in injection volumes compared to the in-situ formation of SUPRAS. When analyzing urine, an alkalinization step before extraction was required. The proposed method produced linear concentration responses with/without internal standard (IS) for the target analytes, with LLOQs within the targeted range of 50 ppb and %RSD within the acceptable 15% range. Furthermore, sample stability studies proved that pre-extracted samples were stable for the short term at room temperature and long-term when frozen.

The "4.3," A New Filler Lips Technique.

The "4.3" technique is a hybrid lip augmentation approach that combines the aesthetic benefits of the vertical-lip technique with the fewer entry points of the retrograde linear technique. This method aims to create natural-looking, harmonious, and defined lips using hyaluronic acid (HA)-based fillers, to enhance volume and contour. The objective of this study is to evaluate the effectiveness, safety, and reproducibility of the "4.3" technique in achieving natural lip augmentation with minimal filler volume and reduced injections. This technique is applied to improve the shape and volume of the lips while minimizing the risk of complications. The technique was applied to male and female patients with standard anatomical features who desired subtle enhancements in lip contour, projection, and volume. The procedure involved four injections in the upper lip and three in the lower lip, using a combination of retrograde linear and vertical techniques. A total of 0.7 mL of HA filler were used for each patient. The "4.3" technique achieved consistent and aesthetically pleasing results across all patients, with improvements in lip volume, shape, and definition. The reduced number of injections minimized discomfort and risk of vascular complications. The use of Tri-Hyal technology contributed to smooth, plump lips with harmonious proportions. The "4.3" technique is a standardized, intuitive, and reproducible method suitable for most patients, regardless of sex. It allows for natural-looking lip augmentation using a reduced volume of filler and fewer injections, making it a safe and effective option for enhancing lip aesthetics.

Enhanced bone cement distribution in percutaneous vertebroplasty using a curved guide wire: a propensity score matching analysis

BackgroundOsteoporotic vertebral compression fractures (OVCF) severely affect the quality of life in the aged population. Percutaneous vertebroplasty (PVP) alleviates pain and stabilizes vertebrae, but suboptimal bone cement distribution can cause complications. Hence, this study aimed to clarify whether a new technique for PVP, using a curved guide wire, enhances the distribution of bone cement and improves clinical outcomes in patients with OVCF.MethodsPatients with single-segment OVCF underwent PVP or curved guide wire percutaneous vertebroplasty (C-PVP). Propensity score matching (PSM) was employed to balanced the baseline characteristics. The primary outcomes were the visual analog scale (VAS) and Oswestry disability index (ODI) scores. The secondary outcomes included assessments of bone cement distribution, bone cement injection volume, radiological parameters, and general clinical results. Additionally, Complications and adverse events were documented.ResultsAfter PSM analysis, each group comprised 54 patients, which significantly reduced baseline differences. The C-PVP group showed better clinical outcomes compared to the traditional PVP group. One month after surgery, the C-PVP group had significantly lower VAS and ODI scores (p < 0.001). These improvements persisted at six months and the final follow-up. Additionally, bone cement distribution scores were better (p < 0.001), injection volume was higher (p = 0.03), leakage was less frequent (p = 0.02), and adjacent vertebral fractures occurred less frequently (p = 0.04) in the C-PVP group. Radiological parameters and overall clinical outcomes revealed no significant differences between the two groups.ConclusionThe use of curved guide wire in PVP significantly improves bone cement distribution and injection volume, resulting in better clinical efficacy in patients with OVCF.

Ultrasound visualization of Botulinum toxin injection: Identifying clinical correlates to optimize outcomes in spasticity management.

Botulinum toxin injections are well established and commonly used for spasticity management. Clinicians strive to optimize outcomes from toxin injections. One potential complication is toxin spread beyond the intended muscle, which can lead to unwanted weakness. The utilization of ultrasound allows direct visualization of target muscles and identification of toxin leakage from the target muscle. Ultrasound evaluation of clinical factors that correlate to toxin leakage have not been studied. To identify cases of botulinum toxin injectate leak beyond the targeted muscle during ultrasound-guided spasticity injections and associate cases of leak with predictive clinical factors, which include muscle size, fibroadipose changes, and number of previous injections. This was a prospective observational study. An outpatient clinic in an academic medical center. Patients who demonstrated wrist flexor spasticity warranting intervention were invited to participate. Patients received standard-of-care spasticity management with injection of onabotulinumtoxinA into the flexor carpi radialis muscle based upon clinical presentation and prescribing guidelines. Ultrasound video was recorded, and a blinded review was conducted by the study team. The primary outcome measure was visualized leak of injectate on recorded ultrasound video. Documented leak was then associated with clinical factors including diameter of the flexor carpi radialis, volume of injectate used, history of prior injections, and fibrotic change of the muscle. The study included 54 patients, 77.8% of whom had an underlying diagnosis of cerebrovascular accident. Injectate leak was observed in 18.5% of injections and could not be confirmed in 9.3% of injections. Multivariable analysis demonstrated increased odds of leak with higher Modified Heckmatt Scale score. No statistically significant increase in leak was noted with higher volume of injectate or smaller muscle diameter. Extramuscular leak of botulinum toxin injection may be associated with fibroadipose muscle change.