Background and objectives: Several new psychoactive drugs for the treatment of psychiatric disorders have been introduced onto the market since the late 1980s. Basic aspects of pharmacodynamics and pharmacokinetics (PK) are investigated before approval for general prescription. Thus, a limited number of subjects are exposed to the drug before it is marketed and only sparse measurements of drug concentration are performed during phases II and III of drug development. The objective of this thesis was to provide further descriptive PK and linked patients data in naturalistic clinical settings. The PK of psychoactive drugs was also studied in the elderly and the young, major risk groups that are exposed in normal everyday clinical practice but that are underrepresented in the phases of drug development. The PK-data were to be assessed by samples sent to the Therapeutic Drug Monitoring (TDM) laboratory service. In a subset of individuals, the genotypes of the cytochrome P450 (CYP) enzymes were described. Results: Serum concentration of the parent compound and its metabolites was provided from TDM-data on antidepressant escitalopram (Paper I) and antipsychotic ziprasidone (Paper II). A large interindividual PK variability was found. The daily dose of the drug was higher than the defined daily dose (DDD) for both escitalopram and ziprasidone (median dose 20 mg and 120 mg, respectively). The median number of drugs per patient, apart from the studied drug, was 4 and 3, respectively (range 1-18). If repeated eligible TDM-data were available, change in treatment strategies could be seen between the first and second sample for the patient, and the metabolite/parent compound (M/P) ratio had lower intraindividual than interindividual variation in the escitalopram study but opposite results were found in the ziprasidone study. The prescription of antidepressant drugs (ADs) in the nursing homes studied was 38 % (Paper III). The concentration of the ADs was higher, or much higher, than could be expected from the dose administered in 73 %. The majority of the elderly people were treated with citalopram. No clear time schedule for how long the drug treatment should continue was found in the patients’ current medical record. The median number of drugs per patient apart from the AD was 11 (range 4-19), no monotherapy was found in these patients. The genetically impaired metabolic activity of CYP enzymes correlated to higher drug concentration as expected, in patients medicated with an AD that is substrate for the CYP enzyme genotype. The concentrations of ADs were as expected from the dose administered in 63 % of the children/adolescents evaluated (Paper IV). The majority of TDM samples requested sertraline. PK outcome of sertraline was similar to the results in adult populations. Monotherapy was documented in 49 % (median number of drugs apart from AD was 1 per patient, range 1-7). Changes in treatment strategies were also shown, if repeated TDM-samples were available. The median variation of the M/P ratio for sertraline between the first and the last samples within the same patient was 20 % (the interindividual variation was 37 %). The poor metabolizers (PM) for CYP2D6 medicated with a CYP2D6 substrate had a lower dose than did non-PM for the same drug. Conclusion: These studies provide reference data for the evaluation of the therapeutic response, i.e. a reference range of what is to be expected in a normal clinical setting, as well as the toxicological information concerning the psychoactive drugs studied. When available, the M/P ratio between two patients’ samples may assess patient compliance, as well as drug-drug interactions. Thus, the use of TDM can be beneficial for individual dose optimisation and drug safety, above all in the studied populations, elderly people and children/adolescents, when the selection of doses requires a consideration of PK parameters. TDM may be a tool for research, increasing knowledge of the psychoactive drug in TDM service, as well as toxicology. A more frequent clinical use of TDM and pharmacogenetic testing in clinical practice would contribute to a better quality when treating with psychoactive drugs.

Peritoneal carcinomatosis (PC) is a common manifestation of both gastrointestinal and gynecologic malignancies. Until recently, this condition was considered beyond curative intent treatment. Since the 1980s, new treatment strategies combining cytoreductive surgery (CRS) with perioperative intraperitoneal and intravenous chemotherapy have emerged. The underlying hypothesis considers CRS responsible for the removal of the macroscopic disease and that perioperative chemotherapy should address the residual microscopic disease. These new treatment regimens have presented encouraging clinical results that contrast with prior failure. The parameters for perioperative chemotherapy are mainly extrapolated from literature on peritoneal dialysis and data from systemic chemotherapy. The overall aim of this thesis was to provide a pharmacokinetic and pharmacodynamic rationale for perioperative intraperitoneal (IP) and intravenous (IV) chemotherapy in PC patients and, to assess its toxicity. After intraoperative IV administration of 5-fluorouracil or ifosfamide, substantial levels of these drugs were found inside the peritoneal fluid and tumor nodules (Papers I and II). This created a pharmacologically advantageous situation whereby a normothermic administered IV drug was subject to the effect of the local hyperthermia in the peritoneal fluid and tumor nodule. High levels of 5-fluouracil, ifosfamide and doxorubicin were observed inside the tumor nodules (Papers I, II and III) and, the identical pharmacokinetic advantage (expressed as Area Under the Curve (AUC) IP/IV ratios)) resulted in different drug levels of doxorubicin according to the density of the tumor nodules (Paper III). These data stressed the importance of pharmacodynamic variables such as tumor nodule density, size, and, vascularity. Therefore, the tumor nodule is proposed as a more appropriate pharmacological endpoint than AUC ratios. After IP Mitomycin C administration in PC patients with a contracted abdomen, mitomycin clearance from the abdomen decreased (Paper IV), which indicated  these patients at risk of under-treatment. Consequently, these pharmacologic data indicate a change in dosimetry for these treatment protocols might be warranted according to the diffusion area. Although diffusional vectors are viewed the main driving force for these treatment protocols, only pharmacokinetic variables such as dose, volume and duration are considered. As pharmacodynamic variables are equally important in the pharmacological assessment of cytotoxic effect, the tumor nodule was proposed as the center of a new conceptual model (Paper I). Mitomycin C data on non-metabolizers ( Paper IV) indicated the cytotoxicity of these cancer chemotherapy protocols is at the level of the individual tumor nodules. The morbidity and mortality of a new bidirectional intraoperative chemotherapy regimen in PC patients was analyzed (Paper V) which provided a means for identifying subsets of patients at risk for increased toxicity. This thesis provides pharmacokinetic and pharmacodynamic guidance for improving perioperative chemotherapy treatment strategies in PC patients and reports its toxicity.

The interplay of transporters and enzymes and their transporter-enzyme was examined in Caco-2 cell monolayer and recirculating perfused rat liver preprations via both theoretical and experimental approaches. First, a Caco-2 catenary model that consisted of the apical, cellular, basolateral compartments and encompasses influx, efflux transporters and enzymes was shown to be superior to the single barrier approach for data interpretation on transporter- and enzyme- mediated processes. The kinetics of baicalein, a flavonoid that undergoes glucuronidation and sulfation, were found to be described better by the catenary model for the complex kinetics of substrate inhibition in metabolism. Second, estradiol-17beta-D-glucuronide (E217G), a protypic substrate of Oatp1a1, 1a4, and 1b2 and Mrp2 that underwent futile cycling with its 3-sulfate metabolite (E23S17G) via estrogen sulfotransferase (Sult1e1) and arylsulfatase C, was examined in the perfused rat liver preparation. Solutions of the AUC and clearances were solved to relate the intrinsic clearances of transporters and enzymes to understand how these affected the apparent clearances in the presence of futile cycling. Transporters and enzymes were perturbed experimentally by the intraportal injection of CC531 colon carcinoma cells for tumor induction in Wag/Rij rat livers. The protein expression of Oatp1a1 and Oatp1b2 were reduced to half whereas Sult1e1 was increased by 40% with tumor development versus the sham-operated control. These data were well predicted by the physiologically-based liver model, showing the impact of increased sulfation intrinsic clearance but not the decreased influx clearance. The TR- (Mrp2 mutant) rat model was used to examine how the absence of Mrp2 for biliary secretion of both E217G and E23S17G affected futile cycling. Absence of Mrp2 was found to result in a pseudo steady-state and reduction of the total, excretion, and metabolic clearances in the liver. The work shed new insight on the interplay between enzymes and transporters and how kinetic processes mediated by enzymes or efflux transporters affected futile cycling.

The interplay of transporters and enzymes and their transporter-enzyme was examined in Caco-2 cell monolayer and recirculating perfused rat liver preprations via both theoretical and experimental approaches. First, a Caco-2 catenary model that consisted of the apical, cellular, basolateral compartments and encompasses influx, efflux transporters and enzymes was shown to be superior to the single barrier approach for data interpretation on transporter- and enzyme- mediated processes. The kinetics of baicalein, a flavonoid that undergoes glucuronidation and sulfation, were found to be described better by the catenary model for the complex kinetics of substrate inhibition in metabolism. Second, estradiol-17beta-D-glucuronide (E217G), a protypic substrate of Oatp1a1, 1a4, and 1b2 and Mrp2 that underwent futile cycling with its 3-sulfate metabolite (E23S17G) via estrogen sulfotransferase (Sult1e1) and arylsulfatase C, was examined in the perfused rat liver preparation. Solutions of the AUC and clearances were solved to relate the intrinsic clearances of transporters and enzymes to understand how these affected the apparent clearances in the presence of futile cycling. Transporters and enzymes were perturbed experimentally by the intraportal injection of CC531 colon carcinoma cells for tumor induction in Wag/Rij rat livers. The protein expression of Oatp1a1 and Oatp1b2 were reduced to half whereas Sult1e1 was increased by 40% with tumor development versus the sham-operated control. These data were well predicted by the physiologically-based liver model, showing the impact of increased sulfation intrinsic clearance but not the decreased influx clearance. The TR- (Mrp2 mutant) rat model was used to examine how the absence of Mrp2 for biliary secretion of both E217G and E23S17G affected futile cycling. Absence of Mrp2 was found to result in a pseudo steady-state and reduction of the total, excretion, and metabolic clearances in the liver. The work shed new insight on the interplay between enzymes and transporters and how kinetic processes mediated by enzymes or efflux transporters affected futile cycling.

Lawsonia intracellularis causes proliferative enteropathies in juvenile mammals. The porcine (PPE) and equine (EPE) diseases are worldwide. Rabbits and hamsters are naturally susceptible, the latter being a classic modeling-host for PPE. None is known for EPE, besides foals. An in vitro evaluation of antimicrobial efficacy against L. intracellularis is difficult. This study aimed to validate a laboratory animal EPE model and to investigate pharmacokinetics (PK) and efficacy of gallium maltolate (GaM) as an alternative antimicrobial therapy. Infected animals were inoculated with cell-cultured L. intracellularis and infection was verified with clinically utilized diagnostic tests. Initially, 2 groups of EPE-infected rabbits were compared to 1 uninfected group. After inoculation (PI), EPE-infected rabbits showed mild clinical signs; detectable seroconversion, fecal shedding, gross lesions in intestinal tissues (IT), and early immuno-histochemistry labeling of L. intracellularis antigen. Thus, a humane EPE-rabbit model was achieved. Subsequently, EPE-infected hamsters were compared to uninfected and PPE-infected hamsters; whereas, PPE-infected rabbits were compared to EPE-infected rabbits. EPE-hamsters did not develop infection, unlike PPE-infected controls; and PPE-rabbits did not develop IT lesions or seroconversion comparable to EPE-rabbits. Therefore rabbits were chosen as the EPE modeling-host for the GaM studies. First, GaM PK and IT concentrations of Ga and Fe were measured. Then, GaM efficacy was compared to a current EPE antimicrobial treatment. During sampling, the intra-arterial catheters in the rabbits’ ears were protected with a novel moleskin-cover, allowing repeated sampling while minimally restrained. The PK study was based on the comparison of EPE-infected and uninfected rabbits, after a single treatment with GaM, collection of serial blood samples and IT samples. The only differing PK parameter, between groups, was a decrease in the terminal phase rate constant of the EPE-rabbits, so a 48h dosing interval was chosen for the efficacy study. In the efficacy study, 3 groups of EPE-infected rabbits were treated with GaM, doxycycline and a placebo, respectively. No differences were noted between treatments, in terms of lesions and fecal shedding. GaM appears no more efficacious than doxycycline in EPE- rabbits. In conclusion, albeit GaM tolerance appeared adequate in rabbits, results do not support its use in EPE-infected animals.

As multidrug resistance in Gram-negative bacilli increases, the old antibiotic colistin has rapidly gained attention as one of few last line treatment options in the form of colistin methanesulfonate (CMS), which is hydrolyzed to colistin both in vitro and in vivo. There is a dearth of knowledge on fundamental aspects of colistin, including pharmacokinetics and optimal dosing regimens. The aim of this thesis was to improve the basis for optimal colistin therapy. To be able to study colistin, an LC-MS/MS assay method was developed which is sensitive, specific and useful in both in vivo and in vitro studies. Using this method we detected a significant loss of colistin during standard laboratory procedures. This loss was characterized and quantified, the hypothesis being that the loss is mainly caused by adsorption to labware. The pharmacokinetics of colistin was studied in two populations of critically ill patients, one with normal renal function and one with renal replacement therapy. Plasma concentrations were assayed with the method above, and population modeling was employed to describe the data. The results include a previously unseen, long elimination half-life of colistin. The data from the population on renal replacement therapy was described without modeling, and showed that both CMS and colistin are cleared by hemodiafiltration. Combination therapy is an approach that is often used when treating patients infected with multidrug-resistant pathogens. The thesis discusses how the joint effect of antibiotics can be measured using colistin and meropenem as a model, and proposes a method for testing antibiotic combinations. Furthermore, a PKPD model was adapted to describe the pharmacodynamics of the combination. In conclusion, a specific and sensitive method for analysis of colistin was developed and the adsorption of colistin to materials was described. The assay method has been well accepted internationally. The pharmacokinetics of colistin and CMS was described in two important patient populations, partly with surprising results that have influenced dosages of colistin worldwide. The pharmacodynamics of combination therapy was investigated and quantified, and the methods applied could be further developed into clinically useful tools for selection of antibiotic combinations.

In this thesis, we explore two important aspects of study of differential equations: analytical and computational aspects. We first consider a partial differential equation model for a static liquid surface (capillary surface). We prove through mathematical analyses that the solution of this mathematical model (the Laplace-Young equation) in a cusp domain can be bounded or unbounded depending on the boundary conditions. By utilizing the knowledge we have obtained about the singular behaviour of the solution through mathematical analysis, we then construct a numerical methodology to accurately approximate unbounded solutions of the Laplace-Young equation. Using this accurate numerical methodology, we explore some remaining open problems on singular solutions of the Laplace-Young equation. Lastly, we consider ordinary differential equation models used in the pharmaceutical industry and develop a numerical method for estimating model parameters from incomplete experimental data. With our numerical method, the parameter estimation can be done significantly faster and more robustly than with conventional methods.

A new optical imaging modality has been developed for small animal in vivo imaging of near-infrared fluorescence resulting from fluorescent contrast agents specifically targeted to molecular markers of cancer. The imaging system is comprised of an intensified charge-coupled device (ICCD) for the detection of ultra-low levels of re-emitted fluorescence following the delivery of an expanded beam of excitation light. The design of the ICCD detection system allows for both continuous wave (CW) and frequency-domain modes of operation. Since the accurate acquisition of frequency-domain photon migration (FDPM) data is important for tomographic imaging, the imaging system was also validated using experimentally obtained FDPM measurements of homogenous turbid media and diffusion theory to obtain estimates of the optical properties characteristic of the media. The experiments demonstrated that the absorption and reduced scattering coefficients are determined least accurately when relative rel measurements of average light intensity IDC are employed either alone or in a rel combination with relative modulation amplitude data IAC and/or relative phase shift data rel . However, when FDPM measurements of are employed either alone or in rel combination with IAC data, the absorption and reduced scattering coefficients may be found accurate to within 15% and 11%, respectively, of the values obtained from standard single-pixel measurements; a result that suggests that FDPM data obtained from an ICCD detection system may in fact be useful in tomographic imaging. Furthermore, intensified-detection allows for sub-second exposure times, permitting the acquisition of dynamic fluorescence images immediately following administration of the contrast agent. Experimental results demonstrate that when coupled with a suitable pharmacokinetic model describing targeted dye distribution throughout the body, dynamic fluorescence imaging may be used to discriminate spontaneous canine adenocarcinoma from normal mammary tissue. A separate experiment demonstrates that pharmacokinetic analysis of dynamic fluorescence images enables one to estimate the rate constant governing Kaposi's sarcoma tumor uptake of an integrin-targeted dye and integrin receptor turnover rate. The rate constant for uptake was calculated to be 0.16-sec-1 while the turnover rate of the integrin receptor was estimated to occur within 24-hours.

<p>Progress in individualized drug treatment is of increasing importance, promising to avoid much human suffering and reducing medical treatment costs for society. The strategy is to maximize the therapeutic effects and minimize the negative side effects of a drug on individual or group basis. To reach the goal, interactions between the human body and different drugs must be further clarified, for instance by using mathematical models. Whether clinical studies or laboratory experiments are used as primary sources of information, greatly</p><p>influences the possibilities of obtaining data. This must be considered both prior and during model development and different strategies must be used. The character of the data may also restrict the level of complexity for the models, thus limiting their usage as tools for individualized treatment.</p><p>In this thesis work two case studies have been made, each with the aim to develop a model for a specific human-drug interaction. The first case study concerns treatment of inflammatory bowel disease with thiopurines, whereas the second is about treatment of ovarian cancer with paclitaxel. Although both case studies make use of similar amounts of experimental data, model development depends considerably on prior knowledge about the systems, the character of the data and the choice of modelling tools. All these factors are presented for</p><p>each of the case studies along with current results. Further, a system for classifying different but related models is also proposed with the intention that an increased understanding will contribute to advancement in individualized drug dosage.</p> / Report code: LiU-Tek-Lic-2007:41.

Enhancing the physicochemical properties of solid-state materials through crystal engineering enables optimization of these materials without covalent modification. Cocrystals have become a reliable means to generate novel crystalline forms with multiple components and they exhibit different physicochemical properties compared to the individual components. This dissertation exemplifies methodologies to generate cocrystals of active pharmaceutical ingredients (API's) based upon knowledge of supramolecular interactions (supramolecular synthons), while focusing on enhanced delivery through in vitro and in vivo processes with both salts and cocrystals respectively. The utility of mechanochemistry involving small amounts of an appropriate solvent, or solvent drop grinding (SDG), has been shown to reliably reproduce cocrystals with the anti-convulsant carbamazepine that were originally obtained by solution crystallization. This technique has been confirmed as a reliable screening method using solvents in which both components exhibit some solubility. The benefits of this technique lie in the time and cost efficiency associated with it as well as its inherently small environmental impact making it a "Green" method. SDG was also used as an efficient way to discover cocrystals of the anti-inflammatory meloxicam with carboxylic acids after analysis of existing reports and the analysis of structural data from the Cambridge Structural Database (CSD) to guide the choice of coformer. It has been shown that SDG can be used to screen for cocrystalline forms that are also obtainable by solution crystallization which is important in later stage development and manufacturing including but not limited to large scale up processes. Single crystals suitable for single crystal X-ray diffraction were obtained with meloxicam and two of the coformers, fumaric and succinic acid. Some of the meloxicam cocrystals exhibited enhanced pharmacokinetic (PK) profiles in rats exemplifying significantly higher serum concentrations after only fifteen minutes and consistently higher exposure over the time studied while others maintained lower exposure. This reveals that cocrystals can fine tune the PK profile of meloxicam in order to reduce or enhance exposure. Two different sulfonate salts, 4-hydroxybenzenesulfonate (p-phenolsulfonate) and 4-chlorobenzenesulfonate, of the anti-spastic agent (R,S) baclofen were developed by strategically interrupting the intramolecularly stabilized zwitterionic structure of baclofen. This zwitterionic structure results in low solubility associated with physiological pH required for intrathecal administration. Structural data for both salts in the form of single crystal X-ray diffraction data was successfully obtained. Solubility based on baclofen was assessed and shown to increase in pure water and at pH's 1 and 7. Only the 4-chlorobenzenesulonate salt maintained an increased solubility over two days at pH 7 making it a viable candidate for further study in terms of intrathecal administration. During crystallization experiments with (R,S) baclofen two polymorphic forms of the baclofen lactam were generated, Forms II and III. Both forms are conformational polymorphs confirmed by single crystal X-ray diffraction and Form II has a Z' of 4 with an unusual arrangement of enantiomers.