It is a well-known fact that drugs can exist in different solid-state forms. These solid-state forms can be either crystalline or amorphous. Furthermore, significant differences are identified between the different solid-state forms of the same drug. Physico-chemical properties that are affected by the solid-state include: melting point, solubility, dissolution rate, stability, compressibility, processability, to name but a few. During the last two decades a significant amount of attention was directed towards the amorphous solid-state forms of drugs. The amorphous form is the direct opposite of the crystalline solid-state. While crystalline forms are constituted by unit cells arranged in a repetitive and structured nature, amorphous forms do not have a long-range order. This lack of order leads to an increase in the Gibbs free energy of such compounds which in turn leads to increased dissolution and solubility. The advantage of improved aqueous solubility and dissolution is a sought after characteristic within the pharmaceutical industry. Improved solubility ultimately could lead to improved bioavailability of a drug. In this study the amorphous nature and stability of amorphous azithromycin was studied. Although previous studies reported that amorphous azithromycin can be easily prepared, there is not a significant amount of data available on the stability of the amorphous form. Furthermore, the effect of milling, mixing, compression, handling and storage on the amorphous form was also investigated. This study showed that amorphous azithromycin remains stable during milling, mixing and compression. A compatibility study on azithromycin when mixed with tableting excipients showed some incompatibilities and this was helpful information to assist with the choice of excipients to be included in the tablet formulation. During the formulation study it became evident that good formulation strategies can greatly improve the flow properties of a drug. The stability of amorphous azithromycin was also studied. During this phase of the study an atypical stability indicating method was used in order to determine and demonstrate the stability of amorphous azithromycin. Dissolution studies were used to illustrate the stability of amorphous azithromycin due to the fact that dissolution is the only method that indicates the phenomena of solution-mediated phase transformation of an amorphous form to a stable crystalline form. During the stability study of six months at 40°C ± 75% RH no recrystallisation of the amorphous form to the crystalline form occurred. It was concluded that amorphous azithromycin will remain stable during processing steps, product formulation and manufacturing as well as during storage for a period of six months at elevated temperature and humidity. / MSc (Pharmaceutics), North-West University, Potchefstroom Campus, 2015

It is a well-known fact that drugs can exist in different solid-state forms. These solid-state forms can be either crystalline or amorphous. Furthermore, significant differences are identified between the different solid-state forms of the same drug. Physico-chemical properties that are affected by the solid-state include: melting point, solubility, dissolution rate, stability, compressibility, processability, to name but a few. During the last two decades a significant amount of attention was directed towards the amorphous solid-state forms of drugs. The amorphous form is the direct opposite of the crystalline solid-state. While crystalline forms are constituted by unit cells arranged in a repetitive and structured nature, amorphous forms do not have a long-range order. This lack of order leads to an increase in the Gibbs free energy of such compounds which in turn leads to increased dissolution and solubility. The advantage of improved aqueous solubility and dissolution is a sought after characteristic within the pharmaceutical industry. Improved solubility ultimately could lead to improved bioavailability of a drug. In this study the amorphous nature and stability of amorphous azithromycin was studied. Although previous studies reported that amorphous azithromycin can be easily prepared, there is not a significant amount of data available on the stability of the amorphous form. Furthermore, the effect of milling, mixing, compression, handling and storage on the amorphous form was also investigated. This study showed that amorphous azithromycin remains stable during milling, mixing and compression. A compatibility study on azithromycin when mixed with tableting excipients showed some incompatibilities and this was helpful information to assist with the choice of excipients to be included in the tablet formulation. During the formulation study it became evident that good formulation strategies can greatly improve the flow properties of a drug. The stability of amorphous azithromycin was also studied. During this phase of the study an atypical stability indicating method was used in order to determine and demonstrate the stability of amorphous azithromycin. Dissolution studies were used to illustrate the stability of amorphous azithromycin due to the fact that dissolution is the only method that indicates the phenomena of solution-mediated phase transformation of an amorphous form to a stable crystalline form. During the stability study of six months at 40°C ± 75% RH no recrystallisation of the amorphous form to the crystalline form occurred. It was concluded that amorphous azithromycin will remain stable during processing steps, product formulation and manufacturing as well as during storage for a period of six months at elevated temperature and humidity. / MSc (Pharmaceutics), North-West University, Potchefstroom Campus, 2015

5 pp. / Soil testing is comprised of four steps: Collection of a representative soil sample, laboratory analyses of the soil sample, interpretation of analytical results, and management recommendations based on interpreted analytical results.

Revised; Originally Published: 2006 / 5 pp.

Soil physical and chemical properties determine a soil's crop production potential and the sustainability of a production system. The objective of this study was to determine the effect of solid and liquid pig manure application on the physical and chemical properties of soil after 5 years of manure application. Solid pig manure increased saturated hydraulic conductivity (Ksat) by 110%, aggregate stability by 30%, available and total phosphorus by 471% and 52% respectively, available nitrogen by 38%, organic carbon by 29% and exchangeable K by 308%, and reduced soil bulk density by 14%. Liquid pig manure (LPM) also increased aggregate stability by 21%, exchangeable K by 45%, available P and total P by 258% and 27%, respectively and, reduced bulk density by 6%. An important finding was the 33% decrease in the concentration of exchangeable Ca in LPM-amended soils. Significant manure by cropping system interaction was also obtained for water retention parameters and available water, total nitrogen and electrical conductivity. There was no effect of pig manure on pH and exchangeable Mg concentrations. Soils under perennial vegetation had 31% greater Ksat, 26% increase in available N, 31% greater available P, 15% greater total P and 12% lower bulk density compared with those under annual crops. Our results show that SPM has a potential as a better organic amendment in improving physical and chemical properties of surface soils. / February 2016

Made available in DSpace on 2014-10-09T12:26:45Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:59:59Z (GMT). No. of bitstreams: 0 / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Made available in DSpace on 2014-10-09T12:26:45Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:59:59Z (GMT). No. of bitstreams: 0 / O descarte de embalagens plásticas de agrotóxicos de forma indevida pode causar sérios problemas de contaminação do solo, principalmente no Brasil, que está em terceiro lugar no mercado de consumo de agrotóxicos. É importante conhecer os processos que afetam o transporte e a potencialidade de contaminação dos agrotóxicos no solo e águas subterrâneas e desenvolver estratégias de remediação. Em virtude de seu impacto na remediação de solos a sorção tem sido muito estudada em pesquisas que envolvam a interação solo-agrotóxico. O principal objetivo deste estudo é avaliar a transferência de agrotóxicos de uma mistura de embalagens comerciais de polietileno de alta densidade, PEAD, usados na agricultura, para o solo e sua remoção pelo tratamento com radiação gama. Duas amostras de solos, um do tipo textura média e o outro de textura muito argilosa, foram expostos à embalagens contaminadas com uma mistura dos agrotóxicos metomil, dimetoato, carbofuram, metildation, triazina, triazofos, atrazina, ametrina, endosulfan, clorpirifós, triazofós e trifluralin. A lixiviação dos agrotóxicos das embalagens para os solos foi homogênea, com pequenas variações, considerando um trabalho experimental. A radiação ionizante apresentou eficiência elevada na degradação dos agrotóxicos de ambos os solos, mas é dependente das características físico-químicas do solo contaminado. A eficiência maior foi obtida para o solo com concentrações maiores de matéria orgânica e umidade. No caso do solo de textura média, a eficiência foi mais elevada, com uma dose absorvida de 20 kGy a totalidade dos agrotóxicos foi removida em todas as camadas. No caso do solo argiloso foi necessário uma dose absorvida maior que 30 kGy para remover a totalidade dos agrotóxicos presentes. / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Knowing the concentrations of the nutrient elements in soils is important due to their toxic effect on humans and the environment. The aims of this study were to assess the effects of water quality, depths and distances of lateral installation on soil chemical properties during turfgrass cultivation. A field experiment was conducted using a Split Split Plot design based on the Randomized complete Block (RCB) with two treatments (well’s and wastewater), and eight sub-treatments (45 and 60 cm distance of the laterals and 15, 20, 25, and 30 cm depths of laterals) in three replicates on a sandy-loam soil, in Shahrekord, Iran. Soil samples were collected from 0-30 and 30-60 cm depth for measuring nitrate (NO3-), electrical conductivity (EC), and pH at the end of the experiment. During the experiment, fecal coliform (FC) were also measured at the soil surface. Results indicated that by increasing lateral distance, NO3- level increased in both layers. With installing laterals in deeper levels, NO3- concentration decreased at the beginning, then increased in the first layer, whereas in the second layer NO3- concentration decreased. In addition, installing laterals in deeper depth, caused an increase in soil EC in the top layer, but a decrease in the lower layer. However, the results showed that there was no significant effect of experimental factors on soil pH. The results also show that with increasing laterals depth, Fc level decreased at the soil surface.

The work presented in this investigation is concerned with the chemical properties of 5-(4-pyridyl)hydantoin as compared with 5-phenylhydantoin.

Even though honey is one of the oldest known sweets, there is a general lack of knowledge concerning its chemical and physical properties. This is particularly true of those honeys produced in the intermountain region. Beekeepers of this region have long felt that their product was sweeter than those honeys produced in other sections of the country. This, of course, implies that honey produced in the intermountain area is higher in sugar concentration and lower in percent moisture. The present study was made in order to supply some data concerning honeys of this area.