Medicine and Health Sciences Commons^™

Experimental Investigation Of The Fluid Velocity Distribution In Stirred Tank Reactors Equipped With Retreat-Blade Impellers Using Laser Doppler Velocimetry, Deepak Rajesh Madhrani

Theses

Stirred tank reactors are commonly used in the pharmaceutical industry for synthesis of Active Pharmaceutical Ingredients (API's) and their intermediates. Typically, these vessels are glass-lined and are provided with a single retreat-blade glass-lined impeller and a single baffle. Despite their ubiquitous utilization in the pharmaceutical industry for at least the past 40 years, the mixing characteristics of these systems have not been studied to any great extent, making it difficult to predict mixing performance in any given operation.

In this work, the velocity distribution inside the typical glass-lined vessel/impeller system was experimentally quantified using Laser Doppler Velocimetry (LDV), which is …

Ultra-Fine Particle Formation Using Principle Of Rapid Expansion Of Supercritical Solutions`, Miraj Minesh Sheth

Theses

There are indications in the chemical and pharmaceutical industries that the reduction in size of a crystalline particle can lead to better performance of the drug compound, particularly for water insoluble drugs, in the final dosage form. Many particle formation techniques have been investigated in recent years by researchers to obtain desired particulate sizes and size distributions. Supercritical fluid technologies have been successfully investigated for particle formation due to its unique gas/liquid properties in the supereritical state. In this report, results of particle formation using the principles of Rapid Expansion of Supercritical Solutions (RESS) have been documented.

In the RESS …

Treatment Of Industrial Wastewater Containing Active Pharmaceutical Ingredients With A Membrane Bioreactor, With The Aim Of Reducing Resource Consumption, Pádraig Colm Ó'Maolcatha

Theses

The biodegradation of a selected active pharmaceutical ingredient (API) during wastewater treatment in a membrane bioreactor (MBR) was examined experimentally. A comparison study was conducted by operating a conventional activated sludge (CAS) pilot plant in parallel to the MBR. The MBR was operated under varying conditions of pH (pH6 and pH8), MLSS (6g/L and l0g/L) and SRT (20 days and 30 days) according to a full factorial design of experiments. In the CAS, pH and SRT were altered as above but MLSS was maintained at 3-4g/L. Comparable average API removal results of 95.5% and 95.7% were obtained for the MBR …

Mathematical Modeling Of Transient State Transdermal Drug Delivery, Alison Nickol Weltner

Theses

In this work, a two-pathway mathematical model for transdermal drug delivery with iontophoresis is presented. The partial differential equations are described and then solved. An alternative, two-pathway, three-layer model is also presented, and the implications of the coefficients within the equation are discussed. Using Franz cell iontophoretic delivery data from three drug substances (amitriptyline HCl, clomipramine HCl, and nortriptyline HCl), the two-pathway model is regressed to determine the diffusion coefficient and the concentration within the skin at the drug reservoir interface. ANOVA analysis indicates a correlation between iontophoretic current and concentration of drug within the stratum corneum.

Characterisation And Optimisation Of Gypsum Crystallization, Catherine H. Shannon

Theses

Gypsum is produced as a by-product during the citric acid production process at ADM Ringaskiddy. The particle size and filterability of the gypsum has a critical bearing on the overall citric acid production rate. Prior to August 1996, research in the area of gypsum crystal optimisation at ADM had concentrated on the application of vortex mixing to perform the gypsum formation reaction. While the gypsum crystals produced with vortex mixing were found to be desirably clear of microcrystalline gypsum, the crystals were considerably smaller and more difficult to filter and wash. This research project sought to retain the advantages conferred …

Optimisation Studies In A Batch Pharmaceutical Company, Sarah Fitzgerald

Theses

This thesis outlines a collaborative project between industry and academia based on a short term research contract.

In the past in Eli Lilly, process optimisation in a multi-purpose, modular building had been mainly confined to equipment commissioning and new product development. It was necessary to embark upon an exercise to develop an optimisation programme m order to meet the increased requirements and demands of the building. Increased market demands, through the introduction of over-the-counter (OTC) drugs, and the demand for cycle time reduction through the expiry of existing patents, made the need for optimisation inevitable.

The purpose of this thesis …