Pharmaceutics and Drug Design Commons^™

Kinetics And Mechanisms Of Crystal Growth Inhibition Of Indomethacin By Model Precipitation Inhibitors, Dhaval D. Patel

Theses and Dissertations--Pharmacy

Supersaturating Drug Delivery Systems (SDDS) could enhance oral bioavailability of poorly water soluble drugs (PWSD). Precipitation inhibitors (PIs) in SDDS could maintain supersaturation by inhibiting nucleation, crystal growth, or both. The mechanisms by which these effects are realized are generally unknown. The goal of this dissertation was to explore the mechanisms underpinning the effects of model PIs including hydroxypropyl β-cyclodextrins (HP-β-CD), hydroxypropyl methylcellulose (HPMC), and polyvinylpyrrolidone (PVP) on the crystal growth of indomethacin, a model PWSD. At high degrees of supersaturation (S), the crystal growth kinetics of indomethacin was bulk diffusion-controlled, which was attributed to a high energy form deposited …

Chemoenzymatic Studies To Enhance The Chemical Space Of Natural Products, Jhong-Min Chen

Theses and Dissertations--Pharmacy

Natural products provide some of the most potent anticancer agents and offer a template for new drug design or improvement with the advantage of an enormous chemical space. The overall goal of this thesis research is to enhance the chemical space of two natural products in order to generate novel drugs with better in vivo bioactivities than the original natural products.

Polycarcin V (PV) is a gilvocarcin-type antitumor agent with similar structure and comparable bioactivity with the principle compound of this group, gilvocarcin V (GV). Modest modifications of the polyketide-derived tetracyclic core of GV had been accomplished, but the most …

A Molecular-Level View Of The Physical Stability Of Amorphous Solid Dispersions, Xiaoda Yuan

Theses and Dissertations--Pharmacy

Many pharmaceutical compounds being developed in recent years are poorly soluble in water. This has led to insufficient oral bioavailability of many compounds in vitro. The amorphous formulation is one of the promising techniques to increase the oral bioavailability of these poorly water-soluble compounds. However, an amorphous drug substance is inherently unstable because it is a high energy form. In order to increase the physical stability, the amorphous drug is often formulated with a suitable polymer to form an amorphous solid dispersion. Previous research has suggested that the formation of an intimately mixed drug-polymer mixture contributes to the stabilization …

Quantification Of Factors Governing Drug Release Kinetics From Nanoparticles: A Combined Experimental And Mechanistic Modeling Approach, Kyle Daniel Fugit

Theses and Dissertations--Pharmacy

Advancements in nanoparticle drug delivery of anticancer agents require mathematical models capable of predicting in vivo formulation performance from in vitro characterization studies. Such models must identify and incorporate the physicochemical properties of the therapeutic agent and nanoparticle driving in vivo drug release. This work identifies these factors for two nanoparticle formulations of anticancer agents using an approach which develops mechanistic mathematical models in conjunction with experimental studies.

A non-sink ultrafiltration method was developed to monitor liposomal release kinetics of the anticancer agent topotecan. Mathematical modeling allowed simultaneous determination of drug permeability and interfacial binding to the bilayer from release …

Multi-Component Microparticulate/Nanoparticulate Dry Powder Inhalation Aerosols For Targeted Pulmonary Delivery, Xiaojian Li

Theses and Dissertations--Pharmacy

The aim of the work was to design, manufacture, and characterize targeted multi-component dry powder aerosols of (non-destructive) mucolytic agent (mannitol), antimicrobial drug (tobramycin or azithromycin), and lung surfactant mimic phospholipids (DPPC:DPPG=4:1 in molar ratio). The targeted dry powder for inhalation formulation for deep lung delivery with a built-in rationale of specifically interfering several disease factors of chronic infection diseases in deep lungs such as cystic fibrosis, pneumonia, chronic bronchitis, and etc. The dry powder aerosols consisting of selected chemical agents in one single formulation was generated by using spray drying from organic solution.

The physicochemical properties of multi-component dry …

Human Butyrylcholinesterase Mutants For Cocaine Detoxification, Shurong Hou

Theses and Dissertations--Pharmacy

Cocaine is one of the most reinforcing drugs of abuse and has caused serious medical and social problems. There is no FDA-approved medication specific for cocaine. It is of a high priority to develop an effective therapeutic treatment for cocaine abuse. Human butyrylcholinesterase (BChE) has been recognized as a promising candidate of enzyme therapy to metabolize cocaine into biologically inactive metabolites and prevent it from reaching central nervous system (CNS). However, the catalytic activity of wide-type human BChE against cocaine is not sufficiently high for treatment of cocaine abuse. Dr. Zhan’s lab has successfully designed and discovered a series of …

Phosphatidylinositol 3-Kinase (Pi3k) As A Therapeutic Target In Nsclc, Christopher W. Stamatkin

Theses and Dissertations--Pharmacy

Deregulated activation of phosphatidylinositol 3-kinase (PI3K) pathway is central to many human malignancies. The functions of this pathway are critical for normal cell metabolism, proliferation, and survival. In lung cancers, the PI3K pathway activity is often aberrantly driven by multiple mutations, including EGFR, KRAS, and PIK3CA. Molecules targeting the PI3K pathway are intensely investigated as potential anti-cancer agents. Although inhibitors of the pathway are currently in clinical trials, rational and targeted use of these compounds, alone or in combination, requires an understanding of isoform-specific activity in context. We sought to identify class IA PI3K enzyme (p110a/PIK3CA, p110b/PIK3CB, p110d/PIK3CD) activities using …

High-Activity Mutants Of Human Butyrylcholinesterase For Cocaine Abuse Treatment, Liu Xue

Theses and Dissertations--Pharmacy

Cocaine is a widely abused drug without an FDA-approved medication. It has been recognized as an ideal anti-cocaine medication to accelerate cocaine metabolism producing biologically inactive metabolites via a route similar to the primary cocaine-metabolizing pathway, i.e. butyrylcholinesterase (BChE)-catalyzed hydrolysis. However, the native BChE has a low catalytic activity against cocaine. We recently designed and discovered a set of BChE mutants with a high catalytic activity specifically for cocaine. An ideal, therapeutically valuable mutant of human BChE should have not only a significantly improved catalytic activity against cocaine, but also certain selectivity for cocaine over neurotransmitter acetylcholine (ACh) such …

Computational Modeling, Design, And Characterization Of Cocaine-Metabolizing Enzymes For Anti-Cocaine Medication, Lei Fang

Theses and Dissertations--Pharmacy

Cocaine is a widely abused and addictive drug, resulting in serious medical and social problems in modern society. Currently, there is no FDA-approved medication specific for cocaine abuse treatment. The disastrous medical and social consequences of cocaine abuse have made the development of an anti-cocaine medication a high priority. However, despite decades of efforts, traditional pharmacodynamic approach has failed to yield a truly useful small-molecule drug due to the difficulties inherent in blocking a blocker like cocaine without affecting the normal functions of the transporters or receptors. An alternative approach, i.e. pharmacokinetic approach, is to interfere with the delivery of …

Towards Elucidation Of A Viral Dna Packaging Motor, Chad T. Schwartz

Theses and Dissertations--Pharmacy

Previously, gp16, the ATPase protein of phi29 DNA packaging motor, was an enigma due to its tendency to form multiple oligomeric states. Recently we employed new methodologies to decipher both its stoichiometry and also the mechanism in which the protein functions to hydrolyze ATP and provide the driving force for DNA packaging. The oligomeric states were determined by biochemical and biophysical approaches. Contrary to many reported intriguing models of viral DNA packaging, it was found that phi29 DNA packaging motor permits the translocation of DNA unidirectionally and driven cooperatively by three rings of defined shape. The mechanism for the generation …

The Pharmacokinetics Of Metal-Based Engineered Nanomaterials, Focusing On The Blood-Brain Barrier, Mo Dan

Theses and Dissertations--Pharmacy

Metal-based engineered nanomaterials (ENMs) have potential to revolutionize diagnosis, drug delivery and manufactured products, leading to greater human ENM exposure. It is crucial to understand ENM pharmacokinetics and their association with biological barriers such as the blood-brain barrier (BBB). Physicochemical parameters such as size and surface modification of ENMs play an important role in ENM fate, including their brain association. Multifunctional ENMs showed advantages across the highly regulated BBB. There are limited reports on ENM distribution among the blood in the brain vasculature, the BBB, and brain parenchyma.

In this study, ceria ENM was used to study the effect of …

Formulation Optimization For Pore Lifetime Enhancement And Sustained Drug Delivery Across Microneedle Treated Skin, Priyanka Ghosh

Theses and Dissertations--Pharmacy

Microneedle (MN) enhanced drug delivery is a safe, effective and efficient enhancement method for delivery of drug molecules across the skin. The “poke (press) and patch” approach employs solid stainless steel MN to permeablize the skin prior to application of a regular drug patch over the treated area. It has been previously shown that MN can be used to deliver naltrexone (NTX) at a rate that provides plasma concentrations in the lower end of the therapeutic range in humans. The drug delivery potential of this technique is, however, limited by the re-sealing of the micropores in a 48-72h timeframe. The …