Governing Land Use in Kenya: From Sectoral Fragmentation to Sustainable Integration of Law and Policy

The research aims to develop a legal and policy framework that will facilitate integration of environmental protection with socio-economic activities during land use decision-making, as a mechanism to achieve sustainability. A statutory duty of care, with respect to land use, would make it clear that land owners or occupiers have definite responsibilities to protect and enhance the sustainability of the land that they use or manage; it would aim to reverse existing land degradation, or include a duty to inform other land owners or the state about some kinds of foreseeable degradation. The paper proposes some models for codes of practice

Governing Land Use in Kenya: From Sectoral Fragmentation to Sustainable Integration of Law and Policy

The research aims to develop a legal and policy framework that will facilitate integration of environmental protection with socio-economic activities during land use decision-making, as a mechanism to achieve sustainability. A statutory duty of care, with respect to land use, would make it clear that land owners or occupiers have definite responsibilities to protect and enhance the sustainability of the land that they use or manage; it would aim to reverse existing land degradation, or include a duty to inform other land owners or the state about some kinds of foreseeable degradation. The paper proposes some models for codes of practice

Estimation of Ethanol/Water Solubility Profiles

The goal of this study was to develop a simple means of estimating the cosolvent/water solubility profile using just the available properties (logKow, dielectric constant etc.) of the solute, cosolvent and water. Ethanol was used as the model cosolvent.One of the most commonly used polarity indicators is the octanol/water partition coefficient (logKow). Numerous programs are used to predict the logKow. The calculated values of logKow from three of the most commonly used programs ClogP®, ACD/logPdb® and KowWin® were compared to experimental values. It was found that all three programs have a user friendly interface but ClogP appears to be more accurate.While the ethanol/water solubility profiles of very polar and very non-polar drugs are monotonic, many semi-polar drugs show a maximum solubility at an ethanol volume fraction (fmax) between zero and one. A new empirical function that describes this deviation from linearity was applied to the experimental data forfifty-one compounds. The proposed model was a more accurate predictor of the co-solvent solubility profile than a general third order polynomial with the samenumber of parameters. The fmax value was also accurately predicted from the first derivative of the model.A sigmoidal relationship was observed between the value of fmax and logKow of the solute. Combining this sigmoidal relationship with the previously reportedlinear relationship between logKow and the initial slope of the plot of log solubility vs. ethanol composition enables the estimation of the totalethanol/water solubility profiles of semi-polar compounds from just logKow.A new bilinear function was also introduced to address the deviation from linearity. This model accounts for both the initial and terminal slopes in theethanol/water solubility profiles of semi-polar solutes. The proposed model is dependent only on logKow and an empirical constant that is cosolvent specific. It is also more accurate than the log-linear model and a general parabolic model.A solubility case study using Antalarmin, a novel stress inhibitor was performed.This study illustrates the use of cosolvents as solubility enhancers as well as pH,surfactants, complexants and lipid based systems

Solubility Improvement of Drugs using N-Methyl Pyrrolidone

The solubilization efficiency of N-methyl pyrrolidone (NMP) has been determined and compared to that of ethanol and propylene glycol for 13 poorly soluble drugs. NMP is found to be a more efficient solubilizer for all the drugs studied. The solubility enhancement as high as about 800-fold is obtained in 20% v/v NMP solution as compared to water. The mechanism of drug solubilization by NMP has also been investigated. It is proposed that NMP enhances drug solubility by simultaneously acting as a cosolvent and a complexing agent. A mathematical model is used to estimate the drug solubility in NMP–water mixture, according to which the total solubility enhancement is a sum of the two effects. This model describes the experimental data well and is more accurate than other models. A large and uniform reduction in the surface tension of water as a function of NMP concentration demonstrates its cosolvent effect. The complexation is supported by the fact that it’s strength is affected by the temperature and the polarity of the medium. A strong correlation exists between log Kow of the drugs and the cosolvency coefficients. The correlation between log Kow and the complexation coefficients is weak suggesting that factors such as molecular shape and aromaticity of the drug molecule are significant in determining the complexation strength. This has been confirmed by the absence of a significant complexation between NMP and linear drug-like solutes

Structure determination and characterization of carbendazim hydrochloride dihydrate

The objective of this study was to synthesize and characterize the hydrochloride salt of carbendazim with the aim of improving the intrinsic solubility of the parent compound. Carbendazim hydrochloride dihydrate was synthesized for the purpose of increasing the aqueous solubility of the parent drug, carbendazim. This was done with the commonly used saturation and cooling method. The structure was determined by single crystal radiograph crystallography, and the hydrochloride salt was found to be a dihydrate. The salt crystallized in a P 21 21 21 (#19) space group, which is typical for nonplanar, achiral, and noncentrosymmetric molecules. The asymmetric unit is comprised of 1 molecule each of carbendazim and chloride and 2 water molecules. The carbendazim molecules arrange themselves in a helical structure, with the waters and the chloride molecules in the channel linking the helix. The crystal lattice is held together by numerous hydrogen bonds, as well as van der Waals interactions. The melting point of the salt is 125.6°C. The solubility of the salt is 6.08 mg/mL, which is a thousand-fold increase from the intrinsic solubility (6.11 μg/mL) of the free base