Currently, many drugs are preclinically tested on two-dimensional cell cultures. However, this method does not adequately replicate the cellular interactions or diffusion gradient that occur in three-dimensional tissues, leading to poor indicators of how a drug may affect human tissues. The objective of this project was to use bioprinted pancreatic cancer cell cultures as a platform for three-dimensional drug testing. Various bioink formulations of cellulose, gelatin, and alginate were evaluated to determine which provided the best printability and cell viability. A cellulose nanocrystal and alginate hydrogel showed superior printability due to its shear thinning properties. Additionally, initial cell viability was nearly 80%, and it remained above 60% over four days. Use of a custom spinning bioreactor at 50 rpm resulted in no improvements to cell viability. Overall, the system shows potential as a drug testing platform to evaluate the effectiveness of various drug formulations on three-dimensional pancreatic cancer cell cultures.

The chapter included the results of the survey indicating that the majority of students agreed with the need, procedures and processes of Virginia Polytechnic Institute and State University's and the NCAA's drug testing programs. This followed by suggested courses of action based on the opinions of the student-athletes toward drug testing. The chapter ends with the author making recommendations based on the research findings. / Master of Science

There were two purposes to this study. First, the study was designed to determine which Virginia public school districts have articulated policies that govern random drug testing of students and if school districts' policies aligned with U.S. Supreme Court standards and Virginia statutes. The second purpose was to ascertain the patterns of practice in selected Virginia school districts that currently conduct random drug testing of students. This included identifying which student groups were being tested and for which drugs. It was also of interest to learn how school districts monitor the testing program and if drug testing practices were aligned with the policies that govern them. Data were gathered by examining student handbooks and district policies in order to determine which school districts had drug testing policies. These policies then were analyzed using a legal framework constructed from U.S. Supreme Court standards that have emerged from case law governing search and seizure in schools. Finally, data on patterns of practice were collected through in-depth interviewing and observation of those individuals responsible for implementing student drug testing in those districts that have such programs. The analyses revealed that the current policies and patterns of practice in random drug testing programs in Virginia public schools comply with Supreme Court standards and state statutes. Student groups subject to testing in Virginia public schools include student athletes and students in extracurricular activities in grades eight through twelve. Monitoring systems in the school districts implementing random drug testing were not consistent. There is evidence that the school districts implementing random drug testing programs have strong community support for the program. / Ed. D.

M. Tech. Pharmaceutical Sciences. / Aims to design, evaluate and optimize an extended release matrix tablet of Nicotinic acid using natural polymers to match the in-vitro dissolution profile of Niaspan.

published_or_final_version / Politics and Public Administration / Master / Master of Public Administration

Thesis (Ph.D.)--University of Texas at Dallas, 2007. / Includes vita. Includes bibliographical references.

Thesis (M.S.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 43-51). Also available on the World Wide Web.

Drug screening is widespread in contexts such as the criminal justice system, employment, and substance abuse treatment centers. Traditionally, drug testing methods have targeted urine matrices and extensive research is available regarding urine drug screening. Due to the nature of sample collection, urine specimen may be tampered or adulterated in efforts to invalidate or pass a drug test. Examples of this include substituting a sample with synthetic urine, diluting a sample with water, or adding a substance to the sample. The addition of a substance is referred to as adulteration and is done in an effort to mask drugs in the sample or to invalidate the test results. For various reasons, including the effects of adulteration, time, and costs associated with urine drug tests, oral fluid (OF) has become an increasingly important alternative matrix for screening drugs of abuse. It offers distinct advantages since tests can be administered noninvasively, quickly, and under observation, thus reducing the risk of tampering. Studies have also shown that drugs of abuse detected in OF may correlate better to user impairment at the time of collection, as compared to other matrices. In 2019, the Substance Abuse and Mental Health Service Administration (SAMHSA) published mandatory guidelines for oral fluid testing. Although these guidelines only directly impact federal spaces, they also serve as a blueprint for developing drug testing laws and policies in other organizations. Despite requirements and procedures controlling for specimen adulteration, it is recognized that manufacturers will continue to develop and market new products to avoid drug detection, just as with urine drug tests. The design of this experiment was to investigate the effects of the commercially available drug testing subversion products High Voltage Saliva Cleanse Mouthwash (High Voltage Detox, Las Vegas, Nevada, USA) and Stinger Detox Mouthwash (Stinger Detox, Phoenix, Arizona, USA) on immunoassay testing for tetrahydrocannabinol (THC) and methamphetamine (MET) in OF. The High Voltage Saliva Cleanse was designated adulterant “A”, and the Stinger Detox was designated adulterant “B”. Two separate immunoassay kits, Discover™ (American Screening Corporation, Inc., Shreveport, Louisiana, USA) and Orawell® (Jiangsu Well Biotech Co., Ltd, Changzhou, Jiangsu, China), were assessed to investigate the differences in performance of the current available test devices in addition to the effects of the subversion products. Using Discover™, samples were spiked according to 0.5 times (x), 1x, and 2x the cutoff concentrations of 50 ng/mL THC and 50 ng/mL MET without adulterant, with Adulterant A, and with Adulterant B. Testing with Orawell® devices was initially conducted at 1x and 2x the cutoff concentrations of 40 ng/mL THC and 50 ng/mL of MET. Based on the lack of response, testing at 0.5x was not conducted. Additional testing was conducted at 1.5x and 3x the cutoff concentrations without adulterant, with Adulterant A, and with Adulterant B. It was concluded that the adulterants affected the test results in the Orawell® device, by producing false positives for drugs of abuse not present in the sample for 17 (56.7%) of the 30 tests containing adulterants. Additionally, it was concluded that both immunoassay tests assessed were lacking in analytical sensitivity and reproducibility.

In drug-testing experiments the primary responses of interest are efficacy and toxicity. These can be modeled as a bivariate quantal response using the Gumbel model for bivariate logistic regression. D-optimal and Q-optimal experimental designs are developed for this model The Q-optimal design minimizes the average asymptotic prediction variance of p(l,O;d), the probability of efficacy without toxicity at dose d, over a desired range of doses. In addition, a new optimality criterion, T -optimality, is developed which minimizes the asymptotic variance of the estimate of the therapeutic index. Most experimenters will be less familiar with the Gumbel bivariate logistic regression model than with the univariate logistic regression models which comprise its marginals. Therefore, the optimal designs based on the Gumbel model are evaluated based on univariate logistic regression D-efficiencies; conversely, designs derived from the univariate logistic regression model are evaluated with respect to the Gumbel optimality criteria. Further practical considerations motivate an exploration of designs providing a maximum compromise between the three Gumbel-based criteria D, Q and T. Finally, 5-point designs which can be generated by fitted equations are proposed as a practical option for experimental use. / Ph. D.

Current screening methods for drug analysis with urine samples includes examination of the sample with an immunoassay. These methods are used to determine the concentration of drug metabolites contained within the sample prior to further confirmatory testing. Drug testing plays a crucial role in maintaining safe workplace environments and safety of individuals. However, a positive result can lead to heavy consequences for the employee including suspension or removal from the workplace. Therefore, a majority of individuals add commonly known products into the sample to evade detection by developing a false negative result. Although specimen integrity examinations are performed to identify tampering of the sample, these results are typically biased on the experience of the examiner. The purpose of this study was to develop an analytical screening technique that will detect the drug of interest as well as the presence of any additional products that may be added into the sample via Direct Analysis in Real Time – High Resolution/Mass Spectrometry (DART-HR/MS) which is an ambient ionization source that produces fast mass spectrum results that can provide semi-quantitative information of the target metabolite concentration. Although there are various studies that indicate the ability of the DART to detect drug compounds, there are no known studies that have examined how real-world urine samples are analyzed. Additionally, there are no current studies that take into consideration adulteration of the urine sample using the DART method. The results obtained in the study showed the ability for DART to identify molecular protonated peaks indicative of dextroamphetamine and/or the presence of masking agents. While the other target drugs could not be identified using this method, the identification of dextroamphetamine, adulterant products and the deuterated internal standard show promise in using this as a screening technique prior to confirmatory tests. Future work is currently being conducted to optimize the protocol for the evaluation of THC, cocaine and benzodiazepines.