Response Surface Methodological Approach toward Optimization of a RP-HPLC Method to Determine Paracetamol in Tablets

Response surface methodology (RSM) was applied to develop an RP-HPLC method in which paracetamol was analyzed and determined on a C18 column with UV detection. To explain more, RSM was used to statistically model the impact of flow rate (ml.min-1) (A), column temperature (°C) (B) and mobile phase composition (H2O: MeOH) (C)on the retention time (RT) of Paracetamol within tablets. Introduction: The major goal of this investigation was to optimize an RP-HPLC method which is simple, linear, accurate, sensitive and selective in determination of Paracetamol in solid dosage forms. Methods and Results:Three distinctive levels were dedicated to each evaluated factor.Box-Behnken experimental design including seventeen independent runs within a range of 25-50% MeOH ratio (mobile phase), 25-45 ºC and 0.7-1.3 mL. min-1 flow rate were carried out to explore the effectivefactors onRT of Paracetamol using RP-HPLC method. ANOVA results revealed that quadratic model was significant (Model F-value of 225.65) and could best describe the relationship between dependent variable (RT) and independent ones: RT= 3.30 - 1.2A - 0.38B - 0.80C + 0.30AC + 0.43BC + 0.53A2 As can be understood from the model terms, the most significant term was the solvent ratio and all the factor levels were indirectly proportional to the Rt. Moreover, the interaction of column temperature and solvent ration seemed to be more important. It was also predicted that optimum assay condition included 1:2 ratio of methanol to water, column temperature of 35ºC and mobile phase flow rate of 1.3 mL.min−1. Using this optimum condition, baseline separation of the drug was achieved with a good resolution and a run time of 2.1 min. The optimized method was validated in terms of linearity, accuracy, limit of detection and limit of quantification of paracetamol within a few commercially available Paracetamol tablets. Conclusions:The optimized RP-HPLC technique provided a convenient and efficient method toward qualitative/quantitative analysis of Paracetamol in its tablets. The improved method is also rapid and sensitive enough to be used for single tablet analysis

Validation of an Analytical Method for Determination of Benzoapyrene Bread using QuEChERS Method by GC-MS

A fast and simple modified QuEChERS (quick, easy, cheap, rugged and safe) extraction method based on spiked calibration curves and direct sample introduction was developed for determination of Benzo[a]pyrene (BaP) in bread by gas chromatography-mass spectrometry single quadrupole selected ion monitoring (GC/MS-SQ-SIM). Sample preparation includes: extraction of BaP into acetone followed by cleanup with dispersive solid phase extraction. The use of spiked samples for constructing the calibration curve substantially reduced adverse matrix-related effects. The average recovery of BaP at 6 concentration levels was in range of 95-120%. The method was proved to be reproducible with relative standard deviation less than 14.5% for all of the concentration levels. The limit of detection and limit of quantification were 0.3 ng/g and 0.5 ng/g, respectively. Correlation coefficient of 0.997 was obtained for spiked calibration standards over the concentration range of 0.5-20 ng/g. To the best of our knowledge, this is the first time that a QuEChERS method is used for the analysis of BaP in breads. The developed method was used for determination of BaP in 29 traditional (Sangak) and industrial (Senan) bread samples collected from Tehran in 2014. These results showed that two Sangak samples were contaminated with BaP. Therefore, a comprehensive survey for monitoring of BaP in Sangak bread samples seems to be needed. This is the first report concerning contamination of bread samples with BaP in Iran. © 2016 by School of Pharmacy

3D hydrogel/ bioactive glass scaffolds in bone tissue engineering: Status and future opportunities

From Elsevier via Jisc Publications RouterHistory: accepted 2023-06-06, issued 2023-07-05Article version: AMPublication status: AcceptedRepairing significant bone defects remains a critical challenge, raising the clinical demand to design novel bone biomaterials that incorporate osteogenic and angiogenic properties to support the regeneration of vascularized bone. Bioactive glass scaffolds can stimulate angiogenesis and osteogenesis. In addition, natural or synthetic polymers exhibit structural similarity with extracellular matrix (ECM) components and have superior biocompatibility and biodegradability. Thus, there is a need to prepare composite scaffolds of hydrogels for vascularized bone, which incorporates bioactive glass to improve the mechanical properties and bioactivity of natural polymers. In addition, those composites' 3-dimensional (3D) form offers regenerative benefits such as direct doping of the scaffold with ions. This review presents a comprehensive discussion of composite scaffolds incorporated with BaG, focusing on their effects on osteo-inductivity and angiogenic properties. Moreover, the adaptation of the ion-doped hydrogel composite scaffold into a 3D scaffold for the generation of vascularized bone tissue is exposed. Finally, we highlight the future challenges of manufacturing such biomaterials

Portfolio of compositions

My Masters research has been to the aim of my development as a composer of original music with an individual voice that is nonetheless informed by the musical and aesthetic currents alive in our contemporary society. This paper is an exegesis on my portfolio of compositions, written during my Masters candidature from 2006-08, in which I pursue a generally-consistent language towards a music that situates itself across a number of dualities with the aim to resolve their opposing strands, while exploring a wide range of thematic and philosophical concerns. The musical analyses contained within demonstrate my compositional technical apparatus which bridges between microstructural cellular detail and an organically unified whole, and promotes a consideration of metaphorical issues that arise through further aesthetic contemplation

The role of extracellular vesicles in malaria biology and pathogenesis

In the past decade, research on the functions of extracellular vesicles in malaria has expanded dramatically. Investigations into the various vesicle types, from both host and parasite origin, has revealed important roles for extracellular vesicles in disease pathogenesis and susceptibility, as well as cell-cell communication and immune responses. Here, work relating to extracellular vesicles in malaria is reviewed, and the areas that remain unknown and require further investigations are highlighted

Audiometry and ossicular condition in chronic otitis media

Introduction: Ossicular chain injury is one of the most common causes of hearing loss in chronic otitis media (COM). Although definite diagnosis of ossicular discontinuity is made intraoperatively, preoperative determination of ossicular chain injury will help the surgeon decide about reconstruction options and hearing prognosis of the patient. In this study we compared preoperative pure tone audiometry (PTA) findings of COM patients with the ossicular condition determined during surgery. Materials and Methods: 97 Patients with COM who underwent ear surgery for the first time were included in the study. A checklist of preoperative clinical findings, audiometric parameters and intraoperative findings was filled out for all patients. Results: Mean amount of Air-Bone Gap (ABG), Bone Conduction threshold (BC) and Air Conduction threshold (AC) of 97 Patients were 35.17, 13.13 and 48.30 respectively. In ears with or without cholesteatoma, granulation tissue, or otorrhea, mean of AC, BC, and ABG were not significantly different. In ossicular erosion and discontinuity (OD), mean of AC and BC thresholds increased significantly but ABG didn’t change significantly. Conclusion: According to the results of this study, in preoperative assessment of COM patients to predict ossicular condition we recommend considering AC, BC and ABG levels together instead of using ABG alone as is routine in our daily practice

Mesenchymal stem cells can survive on the extracellular matrix-derived decellularized bovine articular cartilage scaffold

Objective (s): The scarcity of articular cartilage defect to repair due to absence of blood vessels and tissue engineering is one of the promising approaches for cartilage regeneration. The objective of this study was to prepare an extracellular matrix derived decellularized bovine articular cartilage scaffold and investigate its interactions with seeded rat bone marrow mesenchymal stem cells (BM-MSCs). Materials and Methods: Bovine articular cartilage that was cut into pieces with 2 mm thickness, were decellularized by combination of physical and chemical methods including snap freeze-thaw and treatment with sodium dodecyl sulfate (SDS). The scaffolds were then seeded with 1, 1’-dioctadecyl-3, 3, 3’, 3’-tetramethylindocarbocyanine perchlorate (DiI) labeled BM-MSCs and cultured for up to two weeks. Results: Histological studies of decellularized bovine articular cartilage showed that using 5 cycles of snap freeze-thaw in liquid nitrogen and treatment with 2.5% SDS for 4 hr led to the best decellularization, while preserving the articular cartilage structure. Adherence and penetration of seeded BM-MSCs on to the scaffold were displayed by histological and florescence examinations and also confirmed by electron microscopy. Conclusion: ECM-derived decellularized articular cartilage scaffold provides a suitable environment to support adhesion and maintenance of cultured BM-MSCs and could be applied to investigate cellular behaviors in this system and may also be useful for studies of cartilage tissue engineering

Etiologic evaluation of patients with dysphagia admitted to ENT and Thorax surgery wards of Ghaem Hospital, Mashhad, Northeast of Iran

ntroduction: Dysphagia is a common chief complain of various diseases with different benign or malignant etiologies. Iran is one of countries with a high incidence rate of esophageal cancer. The aim of this study was to evaluate the common causes of dysphagia for earlier diagnosis and treatment of this disease and reduction of its morbidity and mortality rate. Materials and Methods: In this descriptive study, we analyzed the etiology of dysphagia in 200 patients who were admitted to ENT and thorax surgery wards of Mashhad Ghaem Hospital during 2005-2007. Results: Of 200 patients, 79 patients were female and 121 patients were male. The most prevalent cause of dysphagia in these patients was esophageal SCC and the most common endoscopic presentation was the ulcerative view. Other common etiologic factors were esophageal stenosis, adenocarcinoma, mediastinal tumors, achalasia, lyomyoma, sarcoma and diffuse esophageal spasm, respectively. Conclusion: According to these results, the complaint of dysphagia with or without odinophagia has particular clinical importance, especially in our country with high frequency of esophageal malignancies