Aims: To evaluate the stability of Salvianolic acid A (SAA), a promising cardiovascular drug candidate. Additionally avail an archetype in-vitro therapeutic monitoring from SAA degradation profile for characteristic oral gavages.
Study Design: Experimental by laboratory analysis.
Place and Duration of Study: Department of Chemistry & Biochemistry, Moi University; Department of Pure & Applied Chemistry and Department of Medical Laboratory Sciences of Masinde Muliro University of Science & Technology, between June 2013 and September 2014.
Methodology: Drug stability was studied according to ICH guidelines. A stability-indicating HPLC method was developed and validated; mimicking the systemic environs SAA degradation kinetics was then evaluated.
Results: SAA degradation followed first-order kinetics with rate constant increasing from 0.0099 h−1 at 313 K to 0.08044 h−1 at 363 K. The t0.5 was between 70.0 and 9.8 hours while t0.9 was between 10.6 and 1.5 hours within 313 K to 363K temperature range. Activation energy was 39.56 KJmol-1. A V-shaped pH-rate profile was observed with maximum stability at pH4.0. Degradation was rapid in hydrogen peroxide solution and in the simulated gastro-intestinal fluids. SAA exhibits high stability at pH 4.0, hence the suggested optimum pH for processing.
Conclusion: This study provides sufficient physicochemical data depicting SAA to be of intermediate stability. Therefore availing an imperative basis for selecting suitable dosage forms and expected kinetics during therapeutic SAA monitoring.
Moringa oleifera seed was treated and activated to prepare low-cost adsorbents whose adsorption properties would be compared. The uptake for lead, chromium, and cadmium from aqueous solution using the Moringa oleifera seeds biomass (MOS) and Moringa oleifera seed charcoal (CMOS) was studied. CMOS was prepared from MOS in order to make better use of this biomass material. Batch experiments were conducted under varying MOS/CMOS adsorbent dosages (0.5-1.5 g), contact time (30 min–6 hr) and metal ion concentrations (1-50 ppm) for chromium, lead and cadmium. The data for MOS fit well with Langmuir isotherm model for lead (maximum metal uptake (Qm) = 1.281 mg/g) and Cadmium (maximum metal uptake (Qm) = 0.168 mg/g) whereas CMOS can be modelled by both Freundlich and Langmuir isotherms for chromium (adsorption capacity = 0.2202 mg/g) and Lead (maximum metal uptake (Qm) = 0.552 mg/g) respectively. However, the biomass of MOS was found to be more suitable than CMOS for the development of an efficient adsorbent for the removal of chromium, lead and cadmium from aqueous solutions. This study demonstrated that both the charcoal and uncarbonised biomass could be used as adsorbents for the treatment of Cr, Pb and Cd from aqueous solution.
The concentrations of phenol in natural waters were determined so as to ascertain water quality as water intended for human consumption. Total phenols were determined by molecular spectrophotometry, after steam distillation, complexation with 4-aminoantipyrene and extraction into trichloromethane. The dynamic range was 0 - 300 mg/L. Experiments were carried out in the Central Science Laboratory Complex, Taraba State University-Jalingo Nigeria. The research work was completed in 4 months. The experimental method was applied in the analysis of environmental samples (river water and groundwater) collected within Jalingo metropolis of Taraba State, North Eastern Nigeria. Significant amount of phenols were found in the in the natural water samples with a range of 0.2891 - 0.3952 mg/L. The results indicated high pollution of phenol as the values exceeded the tolerance level of 0.0005 mg/L and maximum contaminant level of 0.005 mg/L for phenol allowed by European Communities and Japan’s Ministry of Health, Labour and Welfare respectively for water intended for human consumption. The qualities of natural waters were impaired in terms of phenol and therefore the need for post treatment to make them safe for water intended for human consumption. The water bodies should also be monitored from time to time to ascertain the level of phenol.
The presentations of researchers who have carried out studies on the “Stabilization of metal laden hazardous wastes for disposal in to Secured Land Fill” are reviewed and documented in this paper. The importance of protecting ground water aquifers from getting polluted by leachates of heavy metal-laden soils need not be overemphasized. An attempt is made in this paper to review the present state of different technologies so that site-specific, cost-effective, environmentally sound, technically feasible and socially acceptable technologies can be adopted to solve this problem at local level.
Historically, drug discovery from natural products has been a time and resource-intensive process. Bioassay-guided isolation of natural products often leads to already known compounds of limited, or no chemical or pharmacological interest. Some bioactive compounds are unstable and separation using the traditional approach is often difficult. Full structural elucidation of pure compounds usually requires milligram quantities of compounds and that may require extracting large kilogram quantities of material especially for minor compounds. Rapid detection of biologically active natural products is desired, and to achieve this, dereplication of crude extracts performed prior to isolation work is of crucial importance for avoiding the isolation of a known constituent. Natural products research, as a strategy in drug discovery, has evolved over the last two decades with technological advances in the tools which are prerequisite in isolation and structural elucidation of compounds. Such is the shift from the classical/traditional stand-alone instrumental analytical approaches to newer hyphenated techniques (LC-UV/DAD, LC-MS and LC-NMR).This review describes the general principles and literature applications of these productivity tools in natural products isolation and structural elucidation and also as assay tools for quality control studies, with a discussion on their successes and intrinsic challenges. These hyphenated techniques will advance the course of natural products research and reduce the time and cost invested in the study of natural products, speeding up the drug discovery process.