Incidence of microplastics in the marine ecosystem of the Cíes Islands & surrounding areas of Atlantic Islands National Park, Galicia (NW Spain): seabirds as vectors of plastic contamination

The Atlantic coast of Galicia (Spain) is home to a region called the Rías Baixas where the Atlantic Island National Park and the Cíes Islands lie. These islands are home to the Larus michahellis, or yellow-legged gull. This species is a transport vector for microplastic analysis. The study was conducted in April and focused on cast pellet as well as excrement samples of the yellow-legged gull. KOH and H2O2 digestion and density separation using a ZnCl2 solution were utilized alongside the aid of RAMAN spectroscopy to identify microplastics. Sampling of the sand at Rodas beach was conducted alongside a marine litter survey to quantify the amount of plastic contamination present in the island. The results show that microplastics are present in both the yellow-legged gull samples. Microplastics were present mostly in fiber form (68% of MPs in cast pellets and 48.4% in excrement), with the most common plastic types being sulphones (26% in cast pellets and 29% in excrement), polypropylene (20% in cast pellets and 32.3% in excrement), and cellulose (26% in cast pellets and 19.4% in excrement). Most MP colors were dark (blue, purple, and black; 76% in cast pellets and 71% in excrement) and followed the findings of previous researchers. Additionally, Estimates show that 12.63 million particles of microplastics are deposited each year by the feces of Larus michahellis in the Cíes Islands. The quantity of microplastic items in the sand of Rodas beach can be estimated to be approximately 1.1 million items within the first 5 cm of depth. Sand samples show primarily fibers (49%), with sulphone-based polymers as the most common (52.5%), and dark colors (blue, purple, and black; 78%)O Parque Nacional das Ilhas Atlânticas e as Ilhas Cíes localiza-se nas Rías Baixas, na costa atlântica da Galiza (Espanha). Estas ilhas são local de nidificação da gaivota-de-patas-amarelas (Larus michahellis), espécie conhecida como vetor de transporte de microplásticos. O estudo foi realizado em abril e concentrou-se em regurgitos, bem como em amostras de excrementos da gaivota-de-patas-amarelas. A digestão de KOH e H2O2 e a separação de densidade usando uma solução de ZnCl2 foram usadas juntamente com o auxílio da espectroscopia RAMAN para identificar os microplásticos. Amostras da areia da praia de Rodas foram realizadas paralelamente a um levantamento do lixo marinho para quantificar o nível de contaminação de plásticos presentes na ilha. Os resultados mostram que os microplásticos estão presentes em ambas as amostras de gaivotas-de-patas-amarelas. Estimativas mostram que 12,63 milhões de partículas de microplásticos são depositadas por ano pela população de Larus michahellis nas Ilhas Cíes. Além disso, os microplásticos foram encontrados principalmente na forma de fibra (68% dos MPs nos regurgitos e 48.4% nos excrementos), sulfonas (26% nos regurgitos e 29% nos excrementos), polipropileno (20% nos regurgitos e 32.3% nos excrementos) e celulose (26% nos regurgitos e 19.4% nos excrementos). Muitos dos itens encontrados foram de cor escura (azul, roxo, e preto; 76% nos nos regurgitos e 71% nos excrementos), estando de acordo com estudos anteriores. A quantidade de microplásticos na areia da Praia de Rodas pode ser estimada em aproximadamente 1,1 milhão de itens nos primeiros 5 cm de profundidade. As mostras de areia apresentam principalmente fibras (49%), o polímero mais comum nestas foi o derivado de sulfonas (52.5%), e de cor escuras (azul, roxo, e preto; 78%). Keywords: microplastics; larus michahellis; seabirds; pellet; regurgitation; fece

Formulation and Evaluation of Bilayer Tablet of Acebrophylline and N-Acetylcysteine

This study aimed to develop an immediate-release bilayer tablet of acetylcysteine. Combination of Acebrophylline and Acetylcysteine are indicated for the successful treatment and relief of Asthma. Prepared bilayer tablets were film coated in a conventional coating pan. Formulation properties such as content uniformity, hardness, and friability found to be satisfactory. In vitro dissolution studies of bilayer tablets were conducted for 60 minutes. Samples were analyzed by HPLC. The formulation (F1-F9) showed an acceptable range and complied with the internal specification for weight variation, thickness, hardness, friability, in vitro drug release. The drug content of Acebrophylline and Acetylcysteine in tablet were constant but major degradation of Acetylcysteine to form N,N Diacety-L-cysteine degradation was greatly reduced by the introduction of antioxidants of Propylgallate, Vitamin E, and Butylated Hydroxyl Toluene (BHT) as a variable in 23-factor design of experiments and optimized. Accordingly, A = 398.51 , B = 800, and C = 800 mcg used for optimized batch. The level of N,N Diacety-L-cystine reduced to 0.78. Accelerated stability profile of bilayer tablets was found to be satisfactory. No sign of degradation was observed in HPLC analysis. Hence, it is finally concluded that, the Bilayer tablet technology can be successfully applied for Immediate-release layer of Acebrophylline and Acetylcysteine

Investigation of Guayule's Agronomic Performance and Agro-processing in South Africa

Philosophiae Doctor - PhD (Biotechnology)Guayule (Parthenium argentatum) is grown for its high quality hypoallergenic natural rubber latex production. The plant is native to the Chihuahua desert of North America and successful trials have been done in Europe, the United States of America (USA) and the Republic of South Africa (RSA). It is already undergoing industrial scale development in the USA producing good quality rubber products with impressive stretchiness and strength. The performance of guayule lines AZ1, AZ2, AZ3, AZ4, AZ5, AZ6, OSU1, and 11591 was investigated in the Eastern and Western Cape regions in RSA with an ultimate goal of leading to commercial production. To ensure continuous supply of plants, and avoiding documented seed dormancy issues, a micropropagation protocol was established using the OSU1 guayule line. In addition, laboratory scale latex extraction was accomplished using the Waring blender method with KOH pH 11 buffer and the amount of latex was quantified using the 1 ml latex quantification method. The extracted latex homogenate from the different guayule lines was pooled and purified using Sodium Carboxymethyl Cellulose. The efficiency of different molecular weights (90 000, 250 000 and 700 000) of Sodium Carboxymethyl Cellulose was determined in creaming guayule latex at room temperature and 4 degrees celcius. The optimal creaming results were incorporated into creaming latex extracted from the different guayule lines during this study

Environment-Friendly Construction Materials

Construction materials are the most widely used materials for civil infrastructure in our daily lives. However, from an environmental point of view, they consume a huge amount of natural resources and generate the majority of greenhouse gasses. Therefore, many new and novel technologies for designing environmentally friendly construction materials have been developed recently. This Special Issue, “Environment-Friendly Construction Materials”, has been proposed and organized as a means to present recent developments in the field of construction materials. It covers a wide range of selected topics on construction materials

Design and evaluation of floating drug delivery system of an antihypertensive drug using different natural polymers

In the present study, an attempt was made to formulate individually the floating tablet of Eprosartan mesilate and Acebutolol hydrochloride by effervesecent approach comparing various synthetic and natural polymers by direct compression method to increase the gastric retention of the drug and thus increases the bioavailability of the drug. The principle of gastro-retentive dosage form is to reduce the density of the dosage form less than the density of gastric fluid to increase the gastric residence time by means of effervescent approach using sodium bicarbonate and citric acid as effervescent agent with different natural and synthetic polymers in this research. Intiallly, the procured drugs were identified by FTIR. Then, formulation of floating tablets of Eprosartan mesilate was done in three different stages with Eprosartan mesilate like to study the effect of different polymer on swelling index of the floating tablet, effect of effervescent agent on in vitro buoyancy studies. The results of above two stages were used to eliminate each one polymer from natural and synthetic sources and also to determine the concentration of effervescent agent in terms of ratio used to formulate floating tablets of Eprosartan mesilate in the third stage of formulation development. The result of third stage was used to formulate floating tablets of Acebutolol hydrochloride. From the results of the first stage of formulation development of floating tablets of Eprosartan mesilate, based on swelling index, ethyl cellulose in synthetic source and sodium alginate in natural source were omitted for further screening due to its low swelling index than formulations containing other polymers which may be due to no water absorption capacity of hydrophobic polymer, ethyl cellulose to swell and less water absorption capacity of hydrophillic polymer, sodium alginate to hydrate and swell because of less viscosity of polymer. From the results of the second stage of formulation development of floating tablets of Eprosartan mesilate, based on in vitro buoyancy studies, the highest ratio of sodium bicarbonate and citric acid was used for further formulation devolpment. From the results of the first and second stage of formulation development of floating tablets of Eprosartan mesilate, shortlisted polymers and highest ratio of sodium bicarbonate and citric acid were used to formulate floating tablets of Eprosartan mesilate. From these formulations based on in vitro buoyancy (floating lag time and total floating time), uniformity of drug content and in vitro dissolution studies, formulation containing karaya gum (E7) was selected as best formulation in terms of least floating lag time of 1 sec, total floating time of 580 min, 98.47% released at the end of 600min. It was then subjected to release kinetics analysis and confirmed from the highest correlation coefficient that it follows zero-order nonfickian diffusion controlled system. The best formulation was subjected to drug–excipient compatibility studies and compared with FTIR of pure drug found that there was no interaction with drug and excipients. It was then subjected to stability studies and found that there was no drastic changes in analysed post-compression parameters. It was then analyzed for in vivo experiments like in vivo X-ray studies and in vivo pharmacokinetic studies for predicting its buoyancy and drug release and comparing with in vitro parameters. From the results it was found that buoyancy and was maintained for 10 h in vivo similar to in vitro results and sustained drug release was noticed in vivo similar to in vitro results concluded sustained drug delivery system was achieved. From the above discussed results it was concluded that floating tablet of Eprosartan mesilate containing karaya gum (E7) prolongs the retention of dosage form in gastric area for longer time and thus minimizes the fluctuation in plasma concentration of the drug by frequent dosing of conventional immediate release dosage form. From the results of formulation development of floating tablets of Eprosartan mesilate, shortlisted polymers and highest ratio of sodium bicarbonate and citric acid were used to formulate floating tablets of Acebutolol hydrochloride. From these formulations based on in vitro buoyancy (floating lag time and total floating time), uniformity of drug content and in vitro dissolution studies, formulation containing karaya gum (A 7) was selected as best formulation in terms of least floating lag time of 1 sec, total floating time of 590 min, 98.91% released at the end of 600 min. It 139 was then subjected to release kinetics analysis and confirmed from the highest correlation coefficient that it follows zero-order non-fickian diffusion controlled system. The best formulation was subjected to drug–excipient compatibility studies and compared with FTIR of pure drug found that there was no interaction with drug and excipients. It was then subjected to stability studies and found that there was no drastic change in analysed post-compression parameters. It was then analyzed for in vivo experiments like in vivo X-ray studies and in vivo pharmacokinetic studies for predicting its buoyancy and drug release and comparing with in vitro parameters. From the results it was found that buoyancy and was maintained for 10 h in vivo similar to in vitro results and sustained drug release was noticed in vivo similar to in vitro results concluded sustained drug delivery system was achieved. From the above discussed results it was concluded that floating tablet of Acebutolol hydrochloride containing karaya gum (A7) prolongs the retention of dosage form in gastric area for longer time and thus minimizes the fluctuation in plasma concentration of the drug by frequent dosing of conventional immediate release dosage form. IMPACT OF THE STUDY: Floating drug delivery system offers various future potential like reducing fluctuations in the plasma level of drug resulted from delayed gastric emptying and also by reducing frequent administration of the drug. This delivery system is a beneficial strategy for the local treatment of gastric and duodenal cancers. The buoyancy concept can be utilized in the development of various anti-reflux formulations and these are potential to treat the Parkinson’s disease. In the present research an attempt was made to solve a common critical issue related to the rational development of FDDS include the correlation between prolonged GRT and sustained release and pharmacokinetic characteristics. This created a path of transition from developmental level to the manufacturing and commercial level of gastro-retentive drug delivery system. Further trials could be attempted in future on clinical studies for these best formulations of floating tablet of Acebutolol hydrochloride and Eprosartan mesilate separately

High pressure polymer science, routes to drug delivery

The area of high pressure is receiving great attention and being used to study a range of materials including metals, minerals, energetic materials and pharmaceuticals. Polymers are being increasingly used in pharmaceutical and biomedical applications. The main reason behind this is their physico-chemical characteristics that can be tuned to suit different applications. These characteristics can differ in different forms of the same compound. These forms can be obtained by different techniques including high pressure (Chapter 1).;The work presented in this thesis has used high pressure techniques, including diamond anvil cells (DACs) and large volume press cell, to investigate pharmaceutical polymers and a model active pharmaceutical ingredient (ibuprofen). The change of materials under pressure was studied by in-situ Raman spectroscopy (Chapter 2). The first challenge faced in this project was fluorescence, which hinders Raman spectroscopy.;Surface enhanced Raman spectroscopy (SERS) technique was adopted to improve the signal and overcome fluorescence. This was achieved successfully on weak Raman scattering amino acids and fluorescent polymers (Chapter 3). A range of commonly used polymers were studied under high pressure in DAC. Poly glycolic acid (PGA) and poly lactic acid (PLA) exhibited a similar phenomenon of moving from crystalline or semi-crystalline into a less ordered form between 4-5 GPa. Ethylcellulose (EC) and hydroxypropyl methylcellulose (HPMC) demonstrated a similar change at about 2-3 GPa (Chapter 4).;Both EC and HPMC were used as a platform for sustained release dosage forms in different ratios with ibuprofen. These formulations were mixed using resonant acoustic mixing technique and subjected to high pressure (0.8 GPa) before being tested for drug release. The change in release patterns was mainly caused by the pressure transmitting medium (PTM) rather than the application of pressure (Chapter 5). Individual formulation components were used as received powders, treated by PTM at ambient pressure and subjected to 0.8 GPa before exploring their flowability.;The PTM treatment and pressure has increased the flow function of polymers but not ibuprofen. The formulation blends were tested for flowability in powder and ambient pressure forms. Unlike individual components, the treated blends exhibited a decrease in flow function and increase in cohesion (Chapter 6).;Overall, this thesis demonstrates that the application of pressure, using DACs, on commonly used polymers in pharmaceutical applications does help in inducing phase transitions at different pressures. Adapting SERS technique has been successful in overcoming fluorescence in polymers and improving Raman signal in weakly scattering amino acids. The application of pressure, using large volume press, did not have a significant effect on release pattern of APIs from the tested formulations.;The change was mainly due to the pressure transmitting medium. The effect of pressure was tested on powder flowability and found to increase polymers flowability but not ibuprofen.The area of high pressure is receiving great attention and being used to study a range of materials including metals, minerals, energetic materials and pharmaceuticals. Polymers are being increasingly used in pharmaceutical and biomedical applications. The main reason behind this is their physico-chemical characteristics that can be tuned to suit different applications. These characteristics can differ in different forms of the same compound. These forms can be obtained by different techniques including high pressure (Chapter 1).;The work presented in this thesis has used high pressure techniques, including diamond anvil cells (DACs) and large volume press cell, to investigate pharmaceutical polymers and a model active pharmaceutical ingredient (ibuprofen). The change of materials under pressure was studied by in-situ Raman spectroscopy (Chapter 2). The first challenge faced in this project was fluorescence, which hinders Raman spectroscopy.;Surface enhanced Raman spectroscopy (SERS) technique was adopted to improve the signal and overcome fluorescence. This was achieved successfully on weak Raman scattering amino acids and fluorescent polymers (Chapter 3). A range of commonly used polymers were studied under high pressure in DAC. Poly glycolic acid (PGA) and poly lactic acid (PLA) exhibited a similar phenomenon of moving from crystalline or semi-crystalline into a less ordered form between 4-5 GPa. Ethylcellulose (EC) and hydroxypropyl methylcellulose (HPMC) demonstrated a similar change at about 2-3 GPa (Chapter 4).;Both EC and HPMC were used as a platform for sustained release dosage forms in different ratios with ibuprofen. These formulations were mixed using resonant acoustic mixing technique and subjected to high pressure (0.8 GPa) before being tested for drug release. The change in release patterns was mainly caused by the pressure transmitting medium (PTM) rather than the application of pressure (Chapter 5). Individual formulation components were used as received powders, treated by PTM at ambient pressure and subjected to 0.8 GPa before exploring their flowability.;The PTM treatment and pressure has increased the flow function of polymers but not ibuprofen. The formulation blends were tested for flowability in powder and ambient pressure forms. Unlike individual components, the treated blends exhibited a decrease in flow function and increase in cohesion (Chapter 6).;Overall, this thesis demonstrates that the application of pressure, using DACs, on commonly used polymers in pharmaceutical applications does help in inducing phase transitions at different pressures. Adapting SERS technique has been successful in overcoming fluorescence in polymers and improving Raman signal in weakly scattering amino acids. The application of pressure, using large volume press, did not have a significant effect on release pattern of APIs from the tested formulations.;The change was mainly due to the pressure transmitting medium. The effect of pressure was tested on powder flowability and found to increase polymers flowability but not ibuprofen

PREPARATION OF RAW AND TREATED FLAX STRAW SORBENT FOR OIL SPILL CLEANUP

Oil spill incidents occur around the globe and recovering spilled oil from water or soil has become an important subject. One of the significant methods of oil spill cleanup is known as sorption. Most sorbents are made from synthetic materials. Replacing them with a natural and bio friendly material is a sustainable practice. Flax is grown in Canada and specifically in Saskatchewan. In this study, the possibility of developing a natural sorbent from a by-product of linseed oil production is investigated. Two flax based sorption materials were chemically analyzed: as-received flax straw and processed flax fibers. Various sections of the straw and fiber were observed using scanning electron microscopy (SEM) to view the structure of the plant. The flax straw was cut into small particles of different lengths in order to study the effect of particle size on light and heavy oil uptake. The effect of sorbent density on oil sorption was also determined as well as the effect of shive and fiber. One of the main hinderance to utilizing natural sorbents for oil sorption in aqueous situation is their tendency to adsorb water. To illustrate the behavior of the flax straw in aqueous situations, two experiments were performed on the samples: water uptake and the oil/water selectivity. In order to address the adsorption of water, a chemical acetylation treatment and a proposed novel method for coating sorbents with linseed oil was accessed. Both acetylated and oil coated samples were compared with raw straw to investigate changes in surface morphology, chemical structure, thermal properties, oil sorption and water uptake. The result of chemical analysis showed the cellulose content of flax fiber was higher than flax straw while its hemicellulose and lignin contents were higher. Based on SEM observations, the major portion of the flax straw stem consisted of a hollow inner tube surrounded by xylem and phloem vascular tubes. The vascular tube area is also known as shives and was considerably porous. Hence, shives may be a promising location for depositing oil in oil sorption projects. Also, it was observed the flax and shives were covered with plant wax, and this wax was mostly removed by the acetylation treatment. In the linseed oil coated samples, the plant wax was covered with a thin layer as well as fiber and shive particles. Fourier-transform infrared (FTIR) spectroscopy revealed changes in the intensity of bands related to -OH groups and acetyl groups which is an indication of a successful acetylation treatment. FTIR results of coated samples showed blockage of hydroxyl functional groups and appearance of C-H functional groups related to the linseed oil backbone. The success of acetylation was also validated by thermal gravimetric analysis (TGA). The acetylated samples were observed to have a lower thermal stability compared to raw samples due to a decrease in the number of hydrogen bonds. The TGA results of coated samples were similar to those of raw samples as the coating agent was physically bonded to the sample surface and hence it did not change the structure of the coated sample. In terms of oil sorption capacity, the raw sample is capable of adsorbing 13.6 g/g and 11.2 g/g for heavy and light oil, respectively. The amount of water uptake was 6.9 g/g after 5 min. This number increased to 8.2 g/g after 45 min of soaking within the artificial sea water. Despite the high oil uptake capacity in a dry condition, in aqueous situation raw flax straw only adsorbed 5.6 g/g of heavy oil and 4.6 g/g of light oil. Similarly, the amount of water uptake was more than oil, at 7.6 g/g and 8.5 g/g from the mixture of water and heavy and light oil, respectively. The oil sorption of acetylated samples increased by 6.6 % and 9.8 % for heavy and light oil, respectively compared to raw flax straw. This may be due to the partial elimination of surface wax on the fibers and shives during acetylation which resulted in more regions being accessible within the sorbent particles. Acetylation treatment of flax straw also improved oil/water selectivity. While the amount of water uptake reduced by almost 44 % from the mixture of heavy oil and water, the oil uptake capacity improved by 9 %. For linseed oil coated samples, a considerable improvement of 32 % was observed in water adsorption compared to raw samples during the artificial sea water uptake experiments. Moreover, a drop of 81 % in water uptake and an increase of 38 % for light oil sorption was observed in oil/water selectivity tests for the linseed oil coated samples compared to the raw samples. As a final study, the possibility of reusability and disposal of the oily sorbent within a landfill was examined. It was observed that the linseed oil coated samples maintained 89 % of the oil sorption capacity after four sorption/desorption cycles for light oil and 92 % for heavy oil. It was determined the sorbents can be deposited in a landfill after one cycle of centrifuging based on the code of federal regulations (CFR)