ENHANCEMENT OF DISSOLUTION AND STABILITY OF CANDESARTAN CILEXETIL–LOADED SILICA POLYMERS

Objective: To prepare stable amorphous solid dispersions of candesartan cilexetil (CAN) with different types of silica, including non-porous (aerosil 200) and porous silica (sylysia 350) using the spray-drying method. Methods: various ratios of candesartan cilexetil (CAN) were spray dried with aerosil and sylysia. Powder x-ray diffraction (x-ray) differential scanning calorimetry (DSC), SEM were used to characterize the spray dried powders in addition to dissolution and stability studies. Results: X-ray results showed that the spray–dried (CAN) in the prepared solid dispersion were in amorphous form irrespective of the used silica. In (DSC) analysis, the melting peak of spray-dried (CAN-silica) solid dispersion disappeared. Dissolution property of (CAN) was remarkably improved by formulating with silica particles. In comparing the effect of the type of the silica particles, the dissolution rate of (CAN) from the spray-dried (CAN-sylysia) was faster than that (CAN-aerosil 200) irrespective of the drug content. It was also shown that the spray-dried formulation with silica did not recrystallize when storing at severe storage conditions (40 °C, 75% RH) for three months, while spray-dried (CAN) without silica easily re-crystallized under the same conditions. Conclusion: Spray drying of (CAN) with sylysia 350 is an efficient method to enhance the dissolution and stability of the drug

ENHANCEMENT OF THE RELEASE OF CURCUMIN BY THE FREEZE DRYING TECHNIQUE USING INULIN AND NEUSILIN AS CARRIERS

Objective: Curcumin (CUR), the active ingredient in turmeric has been proven to possess many therapeutic activities chiefly as anti-inflammatory and antioxidant. Unfortunately, CUR suffers from low bioavailability and dissolution due to its poor water solubility. The aim of this work was to enhance the dissolution of CUR by converting it into an amorphous form by freeze-drying and using different carriers. Methods: Different solid dispersions of CUR with Inulin and Neusilin US2 at different ratios using the freeze-drying technique were prepared. The various prepared formulas were characterized using differential scanning calorimetry, X-ray diffraction studies, fourier transform infrared and scanning electron microscopy. Release studies, as well as stability studies of CUR from different formulas, were done. Results: Formulation containing CUR, Inulin and Neusilin US2 at a ratio of 1:5:1 showed the highest CUR release during dissolution testing. The percent CUR release was 98% in comparison with that of 2% from the reference raw material. Physical stability testing showed that CUR remained in the amorphous state for 3 mo. Conclusion: Inulin and Neusilin US2 combinations were found to be effective in enhancing the solubility and dissolution rate of CUR, and stabilizing the amorphous form in the prepared solid dispersion

PREDICTORS OF MAJOR BLEEDING AMONG ATRIAL FIBRILLATION PATIENTS ON WARFARIN

Objective: Bleeding is the most serious complication associated with anticoagulation therapy. The purpose of this study was to estimate the frequency of major bleeding related to warfarin and to identify its predictors in patients with atrial fibrillation (AF). Methods: Patients with AF treated with warfarin at Penang General Hospital in Malaysia were identified according to the international classification of disease, Ninth Revision, Clinical Modification (ICD-9). The medical reports of 1611 patients were reviewed, bleeding events were set as primary end point which were identified in 313 patients. Demographic and clinical data were retrieved and warfarin therapy-related parameters including dose, therapy duration, and prothrombin time-international normalized ratio (PT-INR) were recorded and analyzed using descriptive statistics. Results: Of the 313 patients, 28 patients with major bleeding events were identified. Gastrointestinal bleeding was the major type of bleeding, which accounts for 68% (n = 17) of the cases. The frequency of major bleeding events among all AF patients was 1.7%. High PT-INR value was found in 96.3% (n = 28) of the patients, thereby making it the primary predictor of bleeding events. Other predictors including, advanced age, other comorbidities such as hypertension and multiple anticoagulation therapy were also observed to be significant. Conclusion: Lower doses of warfarin are recommended to achieve target PT-INR range similar to that reported previously for Asian populations. A regular clinical review for bleeding predictors is essential for maximizing the time spent by the patient taking warfarin in the optimal therapeutic range and for making recommended therapy adjustment

Baseline marine investigation and impact of fish farming on the marine environment in Jebel Ali, Dubai, United Arab Emirates

© 2020 Scattered seashells were observed on the seabed with no marine corals. The baseline studies indicate that biodiversity decreased from the northeast to southwest direction. The dominant groups of phytoplankton were diatoms followed by dinoflagellates, with insignificant vertical variations in species composition and population due to shallow water. The benthic diversity over the majority of the study area was relatively low compared with other nearshore areas in the region. All subtidal habitats showed evidence of disturbance to varying degrees, with no fish species recorded at these locations. The soft sediment habitat was found to cover much of the area footprint, and faunal diversity was very low. Fish diversity and abundance were equally poor with only a few demersal species recorded. No evidence of coral colonization was recorded although the presence of a low-profile, encrusting species was recorded in close proximity, to the east of the study area. Mangrove, coral, and seagrass were absent in the study area and its immediate vicinity. Modelling of waste plume suggested that the harbor water is fairly well-mixed, and the dispersion of ammonia attenuates with distance

Assessment of heavy metals in roadside dust along the Abu Dhabi–Al Ain National Highway, UAE

© 2019, Springer-Verlag GmbH Germany, part of Springer Nature. Concentrations of key heavy metals (Pb, Zn, Cd, Ni, Cr, Mn, As, and Hg) have been investigated in roadside dust collected from Abu Dhabi–Al Ain National Highway in UAE. The heavy metals contents were analyzed by atomic absorption spectrometer. Heavy metal levels varied widely from 227.9 to 2765, 19 to 1540, 37.4 to 398.6, 20.1 to 123, 0.3 to 0.7, 0.1 to 0.9, 0.1 to 0.7, and 0.1 to 0.5 mg/kg for Mn, Cr, Zn, Pb, Cd, Hg, Ni, and As, respectively. The spatial distribution pattern showed that different sources of roadway metal emissions dominate at specific locations. Peaks in heavy metal concentrations were frequently observed in locations with high traffic volume, road intersections and junctions, gas and bus stations. Decreased levels of heavy metals were measured in locations with low traffic loadings and in close proximity to farm and forest areas. In addition to traffic-related heavy metals, emissions from fossil fuel and industries remain of significance. Natural sources, through regular dust storms, are important contributors to the observed metal levels. Enrichment factor indicated that As and Ni were entirely originated from crustal sources. Cd, Zn, Pb, and Mn were moderately enriched and are probably derived from mixed sources (traffic flows, gas stations, construction and agricultural activities, among others). Road dust was significantly enriched in Cr and Hg indicating their dominant anthropogenic origin. The average geo-accumulation index values suggested that road dust are uncontaminated with Mn, Ni, and As, uncontaminated to moderately contaminated with Zn and Pb, and moderately contaminated with Cr, Cd, and Hg. The contamination factors indicated very highly contaminated road dust with Cr and Hg, considerably contaminated with Cd, and moderately contaminated with Mn, Zn, and Pb. Results of ecological risk assessment revealed that all heavy metals in road dust pose low risk to local ecosystems, except for Cd and Hg, which constitute potentially considerable risk and high risk, respectively

Long-term trends in ambient fine particulate matter from 1980 to 2016 in United Arab Emirates

© 2019, Springer Nature Switzerland AG. This paper presents the most comprehensive datasets of ambient fine particulate matter (PM 2.5 ) for the UAE from 1980 to 2016. The long-term distributions of PM 2.5 showed the annual average PM 2.5 concentrations constantly exceeded the EPA and WHO guidelines. They varied from 77 to 49 μg/m 3 with an overall average of 61.25 μg/m 3 . While the inter-annual variability in PM 2.5 concentrations showed relatively a cyclic pattern, with successive ups and downs, it broadly exhibited an increasing trend, particularly, over the last 14 years. PM 2.5 concentrations displayed a strong seasonal pattern, with greatest values observed during warm summer season, a period of high demand of electricity and dust events. The lowest values found in autumn are attributable to reduced demand of energy. Decreased atmospheric temperatures and high relative humidity coinciding with this period are likely to reduce the secondary formation of PM 2.5 . The spatial changes in PM 2.5 concentrations exhibited gradual downward trends to the north and northeast directions. Airborne PM 2.5 is prevalent in the southern and western regions, where the majority of oil and gas fields are located. PM 2.5 /PM 10 ratio indicated that ambient aerosols are principally associated with anthropogenic sources. Peaks in PM 2.5 /CO ratio were frequently observed during June, July, and August, although few were concurrent with March. This indicates that secondary formation plays an important role in PM 2.5 levels measured in these months, especially as the photochemical activities become relatively strong in these periods. The lowest PM 2.5 /CO ratios were found during September, October, and November (autumn) suggesting a considerable contribution of primary combustion emissions, especially vehicular emissions, to PM 2.5 concentration. PM 2.5 concentrations are positively correlated with sulfate levels. In addition to sea and dust aerosols, sulfate concentration in the coastal region is also related to fossil fuel burning from power plants, oil and gas fields, and oil industries. The population-weighted average of PM 2.5 in UAE was 63.9 μg/m 3 , which is more than three times greater than the global population-weighted mean of 20 μg/m 3