Bottom sediment in a river often acts as a sink and indicator of changes in water column and magnitude of anthropogenic influences through air and watersheds. Heavy metal concentration in sediments of Ganga River was studied along a 37-km stretch to assess whether there is a significant difference between sites situated upstream and downstream of Varanasi urban core. Metal concentration increased consistently along the study gradient, indicating the influence of urban sources. Concentration in the river sediment was found highest for Fe followed by Mn, Zn, Cr, Cu, Ni, Pb, and Cd. Mann–Kendall trend analysis showed marked seasonality in the concentration with values being highest in summer and lowest in rainy season. Enrichment factor revealed severe enrichment of Cd and Pb at downstream sites, and principal component analysis segregated sites into four distinct groups indicating source relationships. Concentrations of Cd, Pb, Ni, Cu, and Cr did exceed WHO standards. The study has relevance designing control measures and action plans for reducing sediment contamination in anthropogenic impacted rivers.
19 February 2019 in Environmental Science and Pollution Research
This project was aimed to formulate and characterize mucoadhesive buccal tablets of aceclofenac, utilizing different proportions of three polymers carbopol 934, hydroxypropyl methylcellulose, and sodium carboxymethylcellulose. Twelve batches of buccoadhesive aceclofenac were prepared by the direct compression method. The compressed tablets were then evaluated for physicochemical parameters such as hardness, thickness, weight variation, drug content, friability, swelling index, surface pH, and ex vivo mucoadhesion. In vitro dissolution test was conducted for 12 h according to Indian Pharmacopeia 2018, using the rotating paddle method in phosphate buffer of pH 7.4. Physiochemical parameters like weight variation (231.25–268.75 mg), hardness (8.32–11.56 kg), friability (0.04–0.2%), diameter (9.00 mm), thickness (3.8–4.05 mm), and drug content ((97.67–102.25%) were within the acceptable limit as per Indian Pharmacopeia 2018. The swelling index was reported to be in the range of 112.93–450.19%, at 8 h. The surface pHs of all the batches were in between 6.72 to 6.96. The mucoadhesive strengths (40.5–50 g) varied with the change in polymer concentrations especially of carbopol 934. The dissolution profile of all the batches varied greatly, with a maximum release of 109.41% (in batch 12 at 6 h) to a minimum release of 44.82% (in batch 3 at 12 h). Among them, only batch 1 ensured sustained and effective drug release (88.34% at 12 h) with appropriate swelling index (112.93%) and mucoadhesive strength (40 g). Fourier Transform Infrared Spectroscopy analysis showed no evidence of drug excipients interaction. Hence, the results concluded that buccal mucoadhesive aceclofenac tablets can be formulated. Furthermore, the property of the tablet not only depends on the concentration but also the behavior of the polymers used.
Malus domestica (Apple) is one of the most widely cultivated cash crops of Nepal. Jumla and Mustang are two major pocket areas for the production of apple. Flavonoids including quercetin and rutin are potent antioxidants present in apples. This study was designed to quantify and compare the presence of quercetin and rutin in different plant parts (peel, leaf, and bark) among various cultivars of Malus domestica from two pocket zones of Nepal. A new HPLC-UV method was developed and validated for the quantification of quercetin and rutin. Polyphenols, flavonoids, and carbohydrate contents were determined by colorimetric methods. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay was carried out to measure in vitro antioxidative activity. Acid hydrolysis of each extract was carried out by the standard method to measure aglycone quercetin content after hydrolysis of its glycosides. The total rutin content ranged from 3.69±1.34 to 374.50±2.35mg/100g dry extract weight. Before the acidic hydrolysis, the total quercetin content ranged from 2.96±0.13 to 171.05±0.95mg/100g dry extract weight whereas its amount increased highly after the hydrolysis and it ranged from 80.84±19.65 to 7445.32±29.25mg/100g dry extract weight. Total polyphenol content ranged from 19.48±0.23 to 123.48±1.84µg gallic acid equivalent/mg of dry extract weight. Similarly, flavonoid content ranged from 2.21±0.72µg to 755.54±1.91µg quercetin equivalent/mg of dry extract weight. Total carbohydrate content ranged from 144.15±3.73 to 484.65±2.63µg glucose equivalent per 0.5mg dry extract weight. All the extracts showed the various degrees of antioxidant activity in a dose-dependent manner. Among them, stem bark of the Jonathan Jumla showed potent antioxidant activity with IC50 value of 13.003µg/mL. The present study provides the information about variation of the phytochemical content among the different cultivars, parts, and geographic locations. Furthermore, it revealed that bark of Malus domestica cultivars had high quercetin and rutin content with high antioxidant activity.