ENHANCEMENT OF DISSOLUTION RATE OF HYDROCHLOROTHIAZIDE

Objective: The aim of this study was to enhance the dissolution rate of hydrochlorothiazide (HCTZ).Methods: Binary solid dispersions (SDs) of HCTZ with increasing weight ratios of poloxamer 407, polyethylene glycol 6000 (PEG 6000) or gelucire 50/13 were prepared by solvent evaporation technique. The solid dispersions were deposited on the surface of aerosil 200 to produce a dry product with large surface area. The SDs were characterized with respect to drug dissolution. The mechanism of dissolution enhancement was researched using Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC).Results: The unprocessed drug showed erratic, slow dissolution which can be explained on the basis of its hydrophobic nature. Preparation of SDs with hydrophilic carriers resulted in a significant increase in the dissolution rate with most of the drug being liberated in the first 5 min. The dissolution pattern of the drug from the prepared SDs depends mainly on the type of polymer used, and the best dissolution pattern was observed in the SD prepared using 1:1 ratio of the drug to gelucire 50/13 in the presence of aerosil 200 as a carrier. FTIR studies revealed no interaction between the drug and polymers. DSC showed a change in the crystalline structure of the drug after SDs formation. This change can explain the recorded dissolution enhancement.Conclusion: The study presented a system capable of increasing the dissolution rate of HCTZ using polymers which can increase the intestinal permeability as well.Keywords: Hydrochlorothiazide, Poloxamer 407, PEG 6000, Gelucire 50/13, Solid dispersion, Dissolutio

Penetration enhancers in proniosomes as a new strategy for enhanced transdermal drug delivery

AbstractThe aim of this work is to investigate penetration enhancers in proniosomes as a transdermal delivery system for nisoldipine. This was performed with the goal of optimising the composition of proniosomes as transdermal drug delivery systems. Plain proniosomes comprising sorbitan monostearate, cholesterol, ethanol and a small quantity of water were initially prepared. Subsequently, proniosomes containing lecithin or skin penetration enhancers were prepared and evaluated for transdermal delivery of nisoldipine. The plain proniosomes significantly enhanced the transdermal flux of nisoldipine to reach 12.18μgcm−2h−1 compared with a saturated aqueous drug solution which delivered the drug at a rate of 0.46μgcm−2h−1. Incorporation of lecithin into such proniosomes increased the drug flux to reach a value of 28.51μgcm−2h−1. This increase can be attributed to the penetration enhancing effect of lecithin fatty acid components. Replacing lecithin oleic acid (OA) produced proniosomes of comparable efficacy to the lecithin containing system. The transdermal drug flux increased further after incorporation of propylene glycol into the OA based proniosomes. Similarly, incorporation of isopropyl myristate into plain proniosomes increased drug flux. The study introduced enhanced proniosomes as a promising transdermal delivery carrier and highlighted the role of penetration enhancing mechanisms in enhanced proniosomal skin delivery. The study opened the way for another line of optimisation of niosome proconcentrates

INTESTINAL ABSORPTION OF EPROSARTAN MESYLATE FROM SELF EMULSIFYING SYSTEM AND CYCLODEXTRIN COMPLEX

Objective: The aim of this work was to determine the intestinal membrane transport parameters of eprosartan mesylate (EM) and to investigate self-nano emulsifying drug delivery systems (SNEDDS) and inclusion complexation with hydroxypropyl b cyclodextrin (HPbCD) for enhanced intestinal absorption of eprosartan mesylate. Methods: The intestinal absorption was monitored using the in situ rabbit intestinal perfusion technique. SNEDDS was developed using labrafil, Lauroglycol with a tween in the presence of ethanol. Inclusion complexation was achieved by construction of phase solubility diagram in the presence of HPbCD. The prepared complex was evaluated using Fourier Transform Infrared Spectroscopy (FTIR) and differential scanning calorimetry (DSC). Results: The drug was found to be poorly absorbed from the jejuno-ileum and the colon with the absorption being mainly through paracellular pathway. An inclusion complex was developed between the drug and HPβCD. Perfusion of the drug in the nanoemulsion formulation or as an inclusion complex resulted in a significant increase in the intestinal absorption of the drug compared with the control.Conclusion: SNEDDS and inclusion complexation are promising strategies for enhanced intestinal absorption of eprosartan mesylate

Treatment of Sweet Pepper with Stress Tolerance-Inducing Compounds Alleviates Salinity Stress Oxidative Damage by Mediating the Physio-Biochemical Activities and Antioxidant Systems

Salinity stress occurs due to the accumulation of high levels of salts in soil, which ultimately leads to the impairment of plant growth and crop loss. Stress tolerance-inducing compounds have a remarkable ability to improve growth and minimize the effects of salinity stress without negatively affecting the environment by controlling the physiological and molecular activities in plants. Two pot experiments were carried out in 2017 and 2018 to study the influence of salicylic acid (1 mM), yeast extract (6 g L−1), and proline (10 mM) on the physiological and biochemical parameters of sweet pepper plants under saline conditions (2000 and 4000 ppm). The results showed that salt stress led to decreasing the chlorophyll content, relative water content, and fruit yields, whereas electrolyte leakage, malondialdehyde (MDA), proline concentration, reactive oxygen species (ROS), and the activities of antioxidant enzymes increased in salt-stressed plants. The application of salicylic acid (1 mM), yeast extract (6 g L−1), and proline (10 mM) markedly improved the physiological characteristics and fruit yields of salt-stressed plants compared with untreated stressed plants. A significant reduction in electrolyte leakage, MDA, and ROS was also recorded for all treatments. In conclusion, our results reveal the important role of proline, SA, and yeast extracts in enhancing sweet pepper growth and tolerance to salinity stress via modulation of the physiological parameters and antioxidants machinery. Interestingly, proline proved to be the best treatment.</jats:p

Effect of different forms of silica on the physical and mechanical properties of gypsum plaster composites

Gypsum plaster/silica composites prepared by dry blending (0.2-10 %) natural sand, silica fume or silica gel and subsequently hydrated. Their physical and mechanical properties, including normal consistency, setting time, apparent porosity, bulk density and compressive strength, were determined after hydration for 7- and 28-days. The results indicated that adding different forms of silica lowered the bulk density and increased the normal consistency, setting time, apparent porosity and, to some limited extent, compressive strength of the composites. This improvement in properties can be attributed to the existence of silica in the interstitial pores in the hardened plaster matrices. While most of the composites revealed only scant rises in compressive strength, their composition was beneficial in so far as it included either a readily available low-cost constituent (sand) or industrial by-products. Consequently, the formed plaster-silica composites are of economic value, contribute to a cleaner environment by minimizing waste and can be used for applications where high porosity, lightweight units are required or recommended for low-cost buildings.<br><br>Se prepararon pastas compuestas de yeso y sílice mediante la mezcla en seco de yeso con distintas proporciones (0,2- 10 %) de arena natural, o gel o humo de sílice, procediéndose a continuación a su hidratación. A fin de determinar las propiedades físicas y mecánicas de las pastas, a los 7 y los 28 días de hidratación se hallaron su fluidez, tiempo de fraguado, porosidad aparente, densidad aparente y resistencia a la compresión. Los resultados obtenidos indican que al incorporar las distintas modalidades de sílice a la mezcla, disminuyó la densidad aparente y aumentaron la fluidez, el tiempo de fraguado, la porosidad aparente y, en menor medida, la resistencia a la compresión de las muestras. Se considera que esta mejora de las propiedades del material se debe a la presencia de sílice en los poros intersticiales de las matrices endurecidas de yeso. Aunque la resistencia a la compresión de la mayoría de las pastas ensayadas apenas aumentó, estas se beneficiaron de la presencia en su composición de elementos de bajo coste como la arena o los distintos subproductos industriales utilizados. Puede concluirse, por lo tanto, que los compuestos de yeso y sílice tienen valor económico y contribuyen a mejorar el medioambiente al valorizar residuos. Por otra parte, son apropiados para las aplicaciones en las que se necesitan o recomiendan elementos de alta porosidad y bajo peso, concretamente en las edificaciones bajas

Permeability evolution in sandstone due to injection of CO2-saturated brine or supercritical CO2 at reservoir conditions

We measured the change in permeability of two selected sandstones (Berea, Fonteinebleau) due to injection of CO2-saturated (“live”) brine, unsaturated (“dead”) brine or supercritical (sc) CO2 at reservoir conditions. We found that the permeability did not significantly change in a clean sandstone consisting of pure quartz (Fonteinemebleau) due to live or dead brine injection, although permeability changed due to scCO2 injection by ~23%. The permeability in the Berea sandstone, however, changed due to live or dead brine injection, by up to 35%; this permeability reduction in Berea sandstone was likely caused by fines release and subsequent pore throat plugging as the damage was more significant at higher injection rates. We expect that this phenomenon – i.e. rock permeability reduction due to CO2 injection into the formation – can have a significant and detrimental influence on CO2 injectivity, which would be reduced accordingly

The sample of choice for detecting Middle East respiratory syndrome coronavirus in asymptomatic dromedary camels using real-time reverse-transcription polymerase chain reaction

The newly identified Middle East respiratory syndrome coronavirus (MERS-CoV), which causes severe respiratory disease, particularly in people with comorbidities, requires further investigation. Studies in Qatar and elsewhere have provided evidence that dromedary camels are a reservoir for the virus, but the exact modes of transmission of MERS-CoV to humans remain unclear. In February 2014, an assessment was made of the suitability and sensitivity of different types of sample for the detection of MERS-CoV by real-time reverse-transcription polymerase chain reaction (RT-PCR) for three gene targets: UpE (upstream of the E gene), the N (nucleocapsid) gene and open reading frame (ORF) 1a. Fifty-three animals presented for slaughter were sampled. A high percentage of the sampled camels (79% [95% confidence interval 66.9-91.5%, standard error 0.0625]; 42 out of 53) were shown to be shedding MERS-CoV at the time of slaughter, yet all the animals were apparently healthy. Among the virus-positive animals, nasal swabs were most often positive (97.6%). Oral swabs were the second most frequently positive (35.7%), followed by rectal swabs (28.5%). In addition, the highest viral load, expressed as a cycle threshold (Ct) value of 11.27, was obtained from a nasal swab. These findings lead to the conclusion that nasal swabs are the candidate sample of choice for detecting MERS-CoV using RT-PCR technology in apparently healthy camels

A preliminary laboratory study on the salinity and temperature tolerances of some medusae from the São Paulo coast, Brazil

The salinity and temperature tolerances of some species of medusae were studied in the laboratory. The results showed the following order of tolerances in diluted seawater: Cirrholovenia tetranema, Clytia cylindrica and Eucheilota duodecimalis > Proboscidactyla ornata and Obelia spp. > Euphysora gracilis, Ectopleura dumortieri, Liriope tetraphylla and Cunina octonaria. In relation to the decrease of temperature, the following results were obtained: Ectopleura dumortieri, Euphysora gracilis, Obelia spp. and Proboscidactyla ornata > Liriope tetraphylla > Cunina octonaria > Clytia cylindrica and Eucheilota duodecimalis. The results obtained in laboratory were discussed in relation to the distribution of the species in nature.A tolerância de varias espécies de medusas a valores decrescentes de salinidade e temperatura foi estudada em laboratório. Os resultados mostraram a seguinte ordem de tolerância em relação á água do mar diluída: Cirrholovenia tetranema, Clytia cylindrica e Eucheilota duodecimalis > Proboscidactyla ornata e Obelia spp. > Euphysora gracilis, Ectopleura dumortieri, Liriope tetraphylla e Cunina octonaria. Em relação á diminuição de temperatura, os seguintes resultados foram obtidos: Ectopleura dwrortieri, Euphysora gracilis, Obelia spp. e Proboscidactyla ornata > Liriope tetraphylla > Cunina octonaria > Clytia cylindrica e Eucheilota duodecimalis. Estes resultados obtidos em laboratório foram discutidos levando-se em conta a distribuição dessas espécies na natureza