Approximately 50% of medications are not used as prescribed, this phenomenon is known as non-adherence. The literature concerning this phenomenon focuses on reasons medicines are not taken, dissecting experiences to identify mechanisms that act as barriers and facilitators to using medicines as prescribed. Theoretical frameworks and models have been developed that conceptualise the phenomenon, enabling interventions to be established to improve medicines use. However these interventions have yet to demonstrate sustainable improvements in adherence. A novel perspective of the adherence phenomenon may direct future intervention development that will lead to improved adherence. This project evaluated current literature concerning the adherence phenomenon; concluding that a largely ‘biomedical perspective’ had been taken to understanding patients’ medicines use and that further work was needed that approached the phenomenon from with a novel outlook. A systematic review and thematic synthesis was conducted of evidence that, through phenomenological methods, rejected previously held beliefs and concluded that adherence was experienced by patients as an interaction between the patient’s and the medicine’s identity. The systematic review identified a gap in the literature that described adherence from patients’ lived experiences across different disease states. Using phenomenology, empirical research included forty-one interviews that explored patients’ experiences of medicines use across five disease areas, namely cardiovascular disease, gout, chronic obstructive pulmonary disease, cancer and diabetes. This uncovered a novel description of the phenomenon as a construct of social interaction between the patient, their product and wider society (embodied as family and friends, healthcare professionals, the media and policy). Three focus groups were conducted to validate these findings and locate patients’ perspectives of interventions within this novel description. Analyses from these focus groups identified that current adherence interventions represented micro-social interactions between the patient and the product, with few interventions developed that utilise patients’ interactions with wider society. These works are synthesised to present new directions for future intervention development that might seek to utilise patients’ interactions with friends, family, healthcare professionals and policy to improve adherence.

Buccal drug delivery combines the advantage of enhanced patient acceptance/ compliance of oral delivery, with overcoming drug degradation and poor absorption in the gastro intestinal tract (GIT), especially for large molecule therapeutics, such as insulin. Orally disintegrating tablets (ODTs) that dissolve rapidly in the mouth, are gaining widespread popularity, especially with extreme populations, including children and the elderly. This project unifies the advantages of buccal drug delivery with that of ODTs, with the view to developing a non-invasive delivery system for proteins like insulin. This work was carried out in three parallel streams: A Quality by Design (QbD) based characterisation of excipients to identify and predict multi-functional behaviours as binder/ disintegrant/ mucoadhesive agent in ODT formulations; the investigation of a cost effective and easily reproducible cell culture based in vitro method for assessment of buccal delivery; and protein characterisation followed by an in vitro investigation of the effect of basic and acidic amino acids on the solubility, permeability, mechanism and transport route of insulin through TR146 buccal cell culture layers as safe and effective alternative permeation enhancers for proteins. D-mannitol based tablets containing 7% low-substituted hydroxypropyl cellulose (LHPC) with 1.3 % Polyox™ polymers compacted at 30 kN were able to maintain high mechanical properties with fast disaggregation of tablets and mucoadhesive properties. Addition of 1.2 to 1.5 mM Ca2+ to cell culture media was found to increase culture stratification, forming a tighter barrier to paracellular transport of macromolecules, to mimic in vivo barriers. Amino acids were able to significantly enhance insulin solubility in water, and exhibited a concentration-dependent enhancement of insulin permeability (over 400% enhancement) in vitro. Interestingly, results revealed that insulin was transported by an active transcellular process, probably provided by the presence of insulin receptors and amino acid nutrient transporters on the cell membrane. This result obtained for insulin is the first indication of a possible amino acid mediated transport of insulin via formation of insulin-amino acid neutral complexes by ion pairing.

Mesoporous silicas have attracted growing attention in pharmaceutical drug delivery due to their synthetically tailored pore diameters, large pore volume and surface area. The narrow distribution of the pores makes mesoporous silicas exciting as nano-size crystallisation chambers for studies of molecular aggregation and drug polymorphism. Determination and understanding of structure and dynamics of confined solids presents significant analytical challenge due to lack of long range ordering. In this work we demonstrate how solid-state NMR can gain molecular insight into the structures of confined pharmaceuticals which are not accessible with other techniques. Using NMR as a probe for local mobility we demonstrated differences in the molecular dynamics of confined pre-nucleating species as compared to the confined crystals and amorphous molecules embedded in seemingly uniform composites. Indomethacin, tolbutamide and flufenamic acid were chosen as model systems. These compounds differ significantly in structural flexibility leading to a large number of polymorphs and challenges in controlling the phase transitions. Crystallisation processes from amorphous state into confined solvate and stable form V of indomethacin were monitored inside the pores of ca. 30 nm. Using 13C and 1H solid-state NMR we controlled the formation of metastable tolbutamide form V inside the pores of 3 nm, followed by its recrystallisation into the most stable form IH. Using 19F NMR and 19F T1 relaxation measurements we were able to gain molecular level insight into the crystallisation mechanisms of confined crystals, as we demonstrated the formation of a liquid-like layer on the silica surface prior to the build-up of confined crystal of flufenamic acid. All findings from NMR measurements were corroborated with PXRD, DSC and N2 adsorption proving the presence of nano confined crystals. Combined application of nano-size crystallisation methodology and solid-state NMR spectroscopy is essential in directing molecular aggregation and answering fundamental questions on self-assembly of crystalline solids.

Lithium is currently licensed for the treatment and prophylaxis of recurrent affective disorders, treatment of bipolar depression where the use of antidepressants has been ineffective, and the treatment of aggressive or self-mutilating behaviour. Lithium requires therapeutic drug monitoring (TDM) during treatment and evidence is lacking to support the recommended monitoring frequencies of lithium levels. A retrospective analysis of a monitoring database was run to establish the association of single and double exposures of various lithium levels on renal function. Interviews were also conducted with prescribers to establish the factors affecting prescribing decisions related to lithium. This study suggests there is a short-term negative association on renal function after exposures to single, high lithium levels but due to the small patient groups in the multiple exposures analysis the results from this are not statistically reliable. These results did, however, raise the considerations that changes in lithium levels may impact on renal function. This work added to the factors influencing prescribing decisions surrounding knowledge, learning and competence of prescribers with concerns around a lack of knowledge of older drugs seen in newer doctors. Guidance surrounding at what points during the patient’s journey the initial prescribing choice and a decision should be made is also needed. This would help overcome the barrier of split services within mental health and give clearer roles to the various consultants involved in a patient’s care and aid in the involvement of the patient with their treatment. iii The roll out of a centralised lithium monitoring system with access for all those involved in the patients care could be considered to aid in the long-term monitoring of lithium. . This sort of system would also allow for all those involved being able to retain oversight over patients whether or not they are still directly under their care.

This study was designed to investigate the role of AMPA, NMDA, mGlu group I and VPAC₂ receptors (Rs) in the generation of neuropathic pain. Firstly, the behavioural reflex responses of naïve rats to intrathecal administration of low doses of these receptor agonists, singly or in combinations were investigated. Combinations of two or more agonists caused increased behavioural responses to thermal and mechanical stimuli. The combination of AMPA with mGluR group I and VPAC₂R agonists, showed a synergistic effect whereas other combinations were less then additive. Expression of AMPA receptor GluR1 and GluR2 subunits in the superficial dorsal horn was studied using confocal immunofluorescence. In the chronic constriction injury (CCI) model of neuropathic pain both the number of GluR1-immunpositive cell bodies and the level of GluR1 expression in cells decreased significantly in lamina II of the dorsal horn, ipsilateral to the injury. In contrast, there was no change in GluR2 expression or the degree of colocalisation of GluR1 and GluR2 receptor subtypes within individual cells following CCI. The subcellular distribution of GluR1 subunits was also noted to change significantly as a result of CCI. GluR1 subunits were found to redistribute distally into neuronal processes in lamina II cells ipsilateral to CCI and also in response to acute intrathecal AMPA treatment. This redistribution may reflect an increase in the number of GluR1-containing receptors associated with synaptic sites. The relationship between the presynpatic marker protein, bassoon and GluR1-immunopositive cells was investigated showing a significant increase in the number of bassoon immunopositive puncta associated with each GluR1-immunopositive cell ipsilateral to nerve injury. These results suggest that AMPA receptors are important in the central sensitisation underlying neuropathic pain. However, it is clear that several receptors are involved in triggering maximal behavioural responses, and potential therapeutic interventions may be more effective if designed to target more than one receptor type. There is also evidence to suggest that AMPA receptors may have differing roles dependent upon their subtype composition, so subtype-specific antagonists may potentially be useful in treatment of neuropathic pain.

Survivors of acute myocardial infarction (MI) have a high risk of developing chronic heart failure (CHF). In human CHF there is evidence that plasma levels of the potent vasoconstrictor peptide, endothelin (ET)-1 and its precursor big ET-1 are increased, correlate positively with disease severity, and may be important predictors of outcome. The aims of this thesis were to investigate the heart as a source of ET-1 synthesis and to investigate the role of the cardiac ET-1 system during scar formation in the early stages post-MI and also during progression of CHF in a rat model. MI in the rat was induced by surgical ligation of the left anterior descending coronary artery. The myocardial ET system was investigated using immunohistochemical and <i>in situ</i> hybridisation techniques. In the normal heart, immunoreactive ET-1 was identified in the vascular endothelium and myoendothelial cells in the myocardium. Staining for ET-1 was intense and uniform in cardiomyocytes throughout the myocardium. <i>In situ</i> hybridisation confirmed that sites of preproET-1 mRNA expression coincided with sites of immunoreactive ET-1. These results indicate that the myocardium has the capacity to endogenously produce ET-1 in both myoendothelial cells and cardiomyocytes. Investigation of ET-1 immunoreactivity during scar formation 2, 7 and 14 days post-MI indicated an early transient increase in ET-1 in the infarct, which peaks at 7 days. At this time point, ET-1 could be localised to proliferating fibroblasts, infiltrating inflammatory cells and in the endothelia of newly forming vessels, suggesting a role for ET-1 in scar formation early post-MI. Though increased ET-1 staining could be localised at a cellular level in the developing infarct, further studies were needed to identify whether ET-1 was beneficial or detrimental during scar formation. Therefore, the effect on early stage scar formation of an ET_A/B receptor antagonist (A-182086) fed to rats immediately after coronary artery ligation surgery and for the duration (2, 7 or 14 days) of the study was investigated.

Although much is now known of the cellular actions of exogenous opiate drugs and of endogeneous opioid peptides, how these compounds modify interconnecting neuronal systems in the CNS is still poorly understood. The studies described in this thesis have addressed the latter by employing the antibody microprobe technique to investigate (a) the release of dynorphin A(1-8) in the spinal cord of the rat as inflammation develops in peripheral tissues, and (b) the release of cholectystoknin, a putative 'anti-opioid' neuropeptide, in the rat spinal cord following the administration of morphine. A dramatic increase in the spinal synthesis of prodynorphin derived peptides has been observed when inflammation develops in peripheral tissues. The functional significance of this increased synthesis is unclear and there have been no reports of the stimuli needed to produce dynorphin release <I>in vivo</I> of possible controls of such release. Microprobes bearing immobilised antibodies to the dynorphin A(1-8) derivative of prodynorphin, were inserted into the lumbar spinal cord of urethane anaesthetised normal rats and those with a peripheral inflammation, to determine whether dynorphins are being tonically released and how release is altered by manipulating the inflamed tissues. In the absence of any active peripheral stimulus the antibody microprobes detected minimal amounts of immunoreactive (ir)-dynorphin A(1-8) in two areas (lamina I and laminae IV-V) in the dorsal horn of the spinal cord of normal rats. With the development of unilateral ankle inflammation over 3 to 5 days, following subcutaneous injections of Freund's complete adjuvant, this was extended to the ventral horn of both sides of the spinal cord. Lateral compression of the ankles of the normal animals did not release ir-dynorphin A(1-8) during the period of stimulation, but this neuropeptide was detected in the ventral horn following the stimulus.

The purpose of this series of investigations was to elucidate the endogenous control mechanisms active at primary afferent terminals of nociceptive origin in the dorsal laminae of the spinal cord grey matter. Such studies may enable the researcher to make certain conclusions about endogenous mechanisms of pain control in vivo. Furthermore, these studies may help to identify novel areas for the development of analgesic drugs or protocols of therapeutic value in both human and veterinary pain management. Experiments were centred on one particular family of neuropeptides, the tachykinin peptides, and their release in response to peripheral noxious stimulation as determined by the antibody microprobe technique. A review of the anatomy and physiology of tachykinins in the spinal cord is presented at the start of this thesis. The antibody microprobe technique itself is also fully described. Various means of moduling tachykinin release pharmacologically were tested and are presented in this thesis. The results presented here relate to studies on 1) morphine, 2) noradrenaline and the imidazoline derivative drug, medetomidine, 3) neuropeptide Y. A short review on the pharmacological actions of each of these drugs is included. All the results presented are derived from experiments on barbiturate anaesthetised, spinalised cats.

The work in this thesis explores the hypothesis that glucocorticoid-mediated inhibition of angiogenesis is the result of direct modulation of growth factor signalling within the vascular endothelial cells. A well-characterised 2-dimensional <i>in vitro</i> model of human endothelial tube formation was introduced. Glucocorticoids were shown to inhibit tube formation in this model via stimulation of glucocorticoid receptors and this process was not influenced by intra-cellular glucocorticoid metabolism by 11β-hydroxysteroid dehydrogenases. This demonstration that glucocorticoids inhibit angiogenesis by acting directly on the endothelium is consistent with, and extends observations of glucocorticoid-mediated angiostasis in rodent aortic rings and during cutaneous wound healing. Molecular and biochemical assays suggested that glucocorticoids inhibit tube formation by altering the balance of pro and anti-angiogenic factor activity. Time-lapse imaging of tube formation, combined with assays of endothelial cell migration and proliferation, indicated that glucocorticoids reduce tube formation, rather than accelerating degradation of existing tubes, by preventing morphological changes in the cells but do not inhibit cell division or migration. In conclusion, these studies demonstrate that glucocorticoids can inhibit angiogenesis by directly inhibiting morphological changes required for tube formation by endothelial cells but without altering migration or proliferation.

Virtual screening in drug discovery involves processing large datasets containing unknown molecules in order to find the ones that are likely to have the desired effects on a biological target, typically a protein receptor or an enzyme. Molecules are thereby classified into active or non-active in relation to the target. Misclassification of molecules in cases such as drug discovery and medical diagnosis is costly, both in time and finances. In the process of discovering a drug, it is mainly the inactive molecules classified as active towards the biological target i.e. false positives that cause a delay in the progress and high late-stage attrition. However, despite the pool of techniques available, the selection of the suitable approach in each situation is still a major challenge. This PhD thesis is designed to develop a pioneering framework which enables the analysis of the virtual screening of chemical compounds datasets in a wide range of settings in a unified fashion. The proposed method provides a better understanding of the dynamics of innovatively combining data processing and classification methods in order to screen massive, potentially high dimensional and overly imbalanced datasets more efficiently.