Railway Foundation Properties of Some South African Quarry Stones

Abstract: Railway ballasts are broken pieces of hard rock within the grain size range of 25mm - 60mm, over which the railway tracks are laid. Quarries in dolerite, greywake, shale, pebbles and granitic rock formations are some of the major sources of large stones that may be selected as railway ballast based on a range of properties. Flakiness index, Roundness, sphericity and shape factor, and Los Angeles Abrasion indices of samples of the five rock types were determined..

Influence of process variables on the properties of simvastatin self-emulsifying granules obtained through high shear wet granulation

Improvements of the oral bioavailability of lipophilic drugs can be obtained using lipidic formulations such as the self-emulsifying drug delivery systems. The high shear wet granulation (HSWG), using microemulsions as binder, is a viable process to produce self-emulsifying granules. However only few information are present in the literature on the effect of process variables on the properties of the granules obtained with these binders. Consequently, this article compares the effects of some relevant experimental variables (impeller speed and massing time) on thefinal technological and pharmaceutical properties of the granules produced using simple water, or alternatively, a microemulsion as binder and containing simvastatin (SV) as model drug. The effects of the variables were determined by evaluating the granule median diameter, their particle size distribution, roundness, disintegration time and dissolution rate of SV. Results clearly demonstrated that the microemulsion-based process was less sensitive tooperating conditions than the water-based process. With microemulsion the nucleation process and growth regimes were more difficult to control, resulting in products with broader PSDs. At the same operatingconditions microemulsion-based granules were more brittle but rounder and showed smaller median diameter compared to water-based granules. The dissolution rate of simvastatin was not significantly affected by the operating conditions

Synthesis and Characterization of Cowry and Crab Shells Based Chitosan for Drug Delivery

This work aims to synthesize chitosan from locally available cowry and crab shells for Pharmaceutical application in drug delivery. Chitosan was synthesized from both shells using standard deacetylation technique. The synthesized chitosan, piroxicam and lactose were employed in preparing the drug loaded tablets by direct compression technique and subjected to characterization with the aid of Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Spectroscopy (SEM) and optical microscopy. Finally, the drug release rate was investigated with in vitro drug dissolution test. The results of FTIR spectra confirmed that the biopolymer extract was chitosan and it also shows that there was no interaction between chitosan and the piroxicam. The morphological properties of the samples were found to be suitable for drug delivery. The applied load and composition of tablets influenced the drug release rate

Formulation and Evaluation of Gastro Retentive Mucoadhesive Sustained Release Pellets of Acyclovir

Acyclovir is an antiviral drug, belonging to the deoxyguanosine family, widely prescribed for the treatment of herpes simplex viral infections, as well as in the treatment of herpes zoster (shingles). Oral bioavailability of acyclovir is very low (10–20%) owing to its first pass metabolism with elimination half-life (t1/2) of 2-3 h. It has absorption window in upper gastrointestinal tract. Due to its rapid elimination from site of absorption and short biological half life, sustained release formulation system for acyclovir is advantageous. In this study, gastro retentive muco-adhesive SR pellets of acyclovir was prepared using HPMC K 100M as matrix former and Sodium CMC as mucoadhesive polymer by extrusion spheronization technique. Acyclovir pellets prepared with higher concentration of HPMC (batch G) showed in vitro drug release for 12 h with sufficient mucoadhesion strength and ex vivo resident time. Release kinetic studies indicated that drug release data had best fit to Higuchi’s model. In-vivo studies in rat model proved that relative bioavailability of acyclovir SR pellets get increased by 1.98 fold as compared plain drug suspension. The optimized formulation batch G was found to be stable during six months accelerated stability period

Statistically Designed Spheronization and Scale-Up of Ibuprofen Microparticulates Using the Rotor Disk Fluid-Bed Technology: Coating for Prolonged Release and Hard Gelatin Encapsulation of Microparticulates

The aim was to develop uncoated and coated ibuprofen microparticulates in a one-step fluid-bed machine with rotor-disk insert, for immediate and prolonged drug delivery. Feasibilty studies using ibuprofen: Avicel (RC-581; 50:50), sodium lauryl sulfate (1%) as surfactant and water as binder in FLM-15 Vector Flo-coater with 12 stainless-steel and waffle-disk inserts showed that amount of binder, plate type and the presence of surfactant affected most of spheroid characteristics. These variables were used in a 2x2x3 full factorial (replicated) experiment. Blocking was used to study batch-to-batch reproducibility of the process and product variables. Our results confirmed that the binder amount, plate-type and the presence of surfactant were important variables in rotor-disk spheronization. The amount of binder was the most critical. The batch with the most acceptable product characteristics was chosen as the optimized formulation, and used to statistically study the effects of other formulation variables viz, drug particle size (20 µm, 40 µm) and drug load (50%, 65%, 80%) in a 2x3 factorially designed (replicated) experiment. The two ibuprofen particle sizes and the three drug loads were spheronizable. However, spheronization of the higher drug load was more difficult and yielded larger sized microparticulates that consequently retarded drug release. The 65% drug load was therefore used for intermediate size scale-up, which resulted in spheroids with good product characteristics. The optimized scaled-up batch was used in a 2x3 factorially designed (replicated) experiment to study the effects of polymer type (Surelease, Eudragit NE-30D) and level (low, medium, high) on the developed microparticulates. Coating level was found to be inversely related to the drug release. The batch coated with the highest Surelease level yielded the most acceptable spheroid characteristics, including most prolonged release. The latter and the uncoated spheroids were encapsulated using a 2x2x3 experiment in Romaco Index-K150i machine. The average fill-weight of the encapsulated spheroids was mostly affected by the formulation type. Encapsulation of the microparticulates had no undesirable effects on the qualities of both the uncoated and coated pellets. This study provides spheronized ibuprofen microparticulates that can be sold as ready-to-use modified ibuprofen to pharmaceutical companies owing to their lots of pharmaceutical market potentials

Visual evaluation of sliced Italian salami by image analysis.

Visual inspection is an important part of quality control not only for manufacturers but also for retailers and consumers. The object of this investigation was to determine fat content in sliced salami by means of image analysis. The image analysis procedure is applied to digital images of sliced Italian salami produced in 16 different salami factories (A – P). The image analysis method described in this work is non-destructive and the necessary equipment is cheap. It extracts directly interpretable parameters of fat particle morphology (e.g. area, roundness) and number of fat particles from 15 digital images for each sample (A – P). The correlations between the fat features extracted from the images with the chemical fat content measured on the samples were also studied. Good relationships were found between the fat particle characteristics measured by image analysis procedure and the percentage of chemically extractable fat by correlation (R2 = 0.75) and PCA analysis

Decoding Geometric Origin of Geomechanical Properties

Granular materials such as soil and aggregate, are ubiquitous in nature and the understanding of their mechanical behavior is of great importance to better predict and design the civil infrastructure. The particle geometry is a key information to robustly establish the link between the underlying grain-scale mechanisms and the macroscopic behavior of granular materials. However, the characteristics of the particle geometry remain to be better understood. For example, we do not know how the volume is related to the surface area for irregularly shaped particles in general. Their relation clearly depends on the morphology, dictating that volume, surface area, and morphology are interrelated. Then, the remaining question is how the size of a particle would be related to those three geometric properties. The interrelation of these four geometry parameters is the key information to fundamentally understand their concerted influence on the complex behavior of granular materials, but we do not have the answer in the body of knowledge yet. The research in this dissertation advances the understanding of grain-scale origin of the complex macroscale behavior of granular materials and creates a set of new knowledge as follows: (i) This study systematically addresses the influence of coarse aggregate angularity on cemented granular materials. It shows that cemented granular materials with round aggregates have superior small-strain performance, while the materials with angular aggregates have superior large-strain performance; (ii) This study develops a new theory for comprehensive 3D particle geometry characterization by proposing a formulation M = A/V×L/6, which translates the 3D particle morphology M as a function of surface area A, volume V, and size L; (iii) This dissertation is benefited by the early adoption of 3D-printing for geomechanical testing. Laboratory direct shear tests have been conducted on 3D-printed synthetic particles with different geometry, to robustly correlate the geometric properties of particles to geomechanical properties of the granular materials. (iv) This study unravels, for the first time, the power law relationship between A/V ratio and V for coarse aggregate in nature. This relationship is the key to predict morphology using volume measurement only, thus significantly reducing the effort of particle geometry characterization

Flow test evaluation

Issued as final reportGeorgia Department of Transportatio