Nanoparticulate delivery systems have been widely used in recent decades, available in a wide variety of structures, for targeted drug delivery. They provide controlled and prolonged release for drugs, peptides and biopharmaceuticals. Ceramic nanoparticles are one of the various nanocarriers, which have been employed in local targeted delivery, most commonly in the area of orthopaedic drug delivery to enhance treatment therapies. This thesis therefore focused on the development of aquasomes, a ceramic nanoparticulate carrier system, for the delivery of proteins, growth factors and antibiotics for its potential application in bone regeneration in fracture healing. The suitability of non-aqueous silicone elastomer gels (NASEGs) as a topical/transdermal delivery system for proteins as well as protein-loaded aquasomes was also investigated. Through process optimisation, a suitable lyophilisation method was developed and used for the preparation of bioactive aquasome formulations of growth factors, bone morphogenetic protein (BMP-2), vascular endothelial growth factor (VEGF-121), and antibiotic, gentamicin. Physical characterisation of aquasomes using zeta potential and optimisation of preliminary aquasome formulations were optimised by utilising smaller nanocore sizes. In addition, scanning electron microscopy (SEM), confocal microscopy analysis and entrapment efficiency studies were performed to ascertain the drug loading efficiency of the different aquasome formulations. BMP-2 loading aquasomes exhibited an entrapment efficiency of 98.9% Protein loading on aquasomes yielded a higher negative zeta potential in comparison to blank nanocores. Confocal microscopy images elucidated the behaviour of nanocore particles showing agglomeration of nanocores and the presence of fluorescent drug adsorbed onto nanocores. The bioactivity of the aquasome formulations were analysed via in vitro cell culture model assays and microbiological assays. BMP-2-loaded aquasomes were investigated for enhanced osteogenic proliferation and differentiation effects on osteoblast-like cells, MG63 cells. The enhanced osteogenic effect of HUVECs in co-culture with these cells was also examined. In addition, the committed differentiation of ATMSCs into osteoblasts induced by their exposure to BMP-2 -loaded aquasomes was also investigated. Results exhibited the enhanced osteogenic differentiation effect, analysed by alkaline phosphatase (ALP) secretion (a major biochemical marker of osteoblastic differentiation) from MG63 cells was dependent on the protein loading onto the aquasome formulation. However, differentiation of ATMSCs cultured in osteogenic medium was significantly higher than ATMSCs exposed to BMP-2 or VEGF-121 treatments. Gentamicin-loaded aquasomes were investigated for their antimicrobial activity against Staphylococcus aureus, a major pathogen popularly implicated in cases of osteomyelitis. Results showed that gentamicin released from aquasomes exhibited excellent bactericidal activity against bacterial cultures without any reproduction of bacteria in 24 hours. In conclusion, the aquasome formulations were able to offer controlled release of bioactive antimicrobials and growth factors over a prolonged duration. The amount of bio-actives released was dependent on the loading of the bio-actives in the fabrication process of aquasome formulations. However, minute (ng/μg) amounts of adsorbed growth factor/drug were observed in comparison to the loading (high ng/mg) within the duration of study. It can be inferred these aquasomes can be employed in the sustained local and targeted delivery of antimicrobials and growth factors in orthopaedic treatments for enhanced fracture healing. However, the loading of bio-actives onto aquasome formulations may need to be optimised to increase the amount of bio-actives released to elicit more pronounced pharmacological effects.

The blood brain barrier (BBB) poses a significant hurdle to brain drug delivery. However, the location of the olfactory mucosa, within the nasal cavity, is a viable target site for direct nose-to-brain (N2B) delivery, thereby bypassing the BBB. To exploit this target site innovative nasal formulations are required for targeting and increasing residency within the olfactory mucosa. We developed and characterised three formulation systems for N2B delivery, (i) thermoresponsive mucoadhesion nasal gels sprays; (ii) mesoporous silica nanoparticles and (iii) nasal pMDI devices. We developed an optimal mucoadhesive formulation system incorporating amantadine as a model, water-soluble anti-Parkinson’s drug using carboxymethy cellulose and chitosan as mucoadhesives. Formulations demonstrated droplet sizes of < 130mm and stability over 8-weeks when stored at refrigeration conditions with no significant cellular toxicity against olfactory bulb (OBGF400) and nasal epithelial (RPMI 2650) cells. Mesoporous silica nanoparticles (MSNP) were prepared (~220nm) and demonstrated cellular uptake into OBGF400 within 2-hours of incubation with minimal toxicity. MSNP were loaded with two novel phytochemicals known to possess CNS activity, curcumin and chrysin, with loading efficiencies of ~12% confirmed through TGA, DSC and HPLC-UV analysis. Furthermore, a pH dependant release profile was identified with curcumin with greater release at nasal cavity pH 5.5 compared to pH 7.4. Furthermore, successful incorporation of MSNP into nasal gels was demonstrated through rheological studies with a decrease in Tsol-gel. A pilot study was conducted to assess the feasibility of modified existing pulmonary pMDI to deliver diazepam intranasally, targeting the olfactory mucosa. Diazepam was formulated with HFA134a and using ethanol as a co-solvent, and demonstrated stability in formulation over 3 months. Deposition studies within a nasal cast model demonstrated 5-6% deposition onto the olfactory mucosa under optimal administration conditions in the absence of any nozzle attachments. Our studies have provided a basis for the development to innovative intranasal formulation systems potentially capable of targeting the olfactory mucosa for both water soluble and poorly soluble drugs.

The incidence of skin cancer is increasing and conventional treatments such as surgery are not suitable for all patients. This study aimed to develop an elastic liposomal gel to be applied directly to the tumour for the controlled release of anti-cancer agents to the dermal layer. The proposed anti-cancer flavonoids EGCG and naringenin as well as the novel potent cytotoxic agent MTL-004 were loaded into the bilayer of liposomes. Furthermore, aqueous gels HEC and HPMC were investigated as carriers for the liposomes to be applied topically. Liposomes loaded with either Tween 80, Tween 20 or sodium cholate were found to have increased elastic properties, liposomes with an average size of 400 nm were able to pass through a pore size of 100 nm. Release studies from liposomes loaded with either EGCG, naringenin and MTL-004 as well as varying ratios of Tween 20 were carried out. Within 24 hours, EGCG liposomes loaded with 0% or 10% w/w Tween 20 gave a release of 13.7 ± 1.1 % and 94.4 ± 4.9 % respectively; naringenin liposomes loaded with 0% or 10% w/w Tween 20 gave a release of 109.7 ± 5.0 % and 48.5 ± 2.1 % respectively; MTL-004 liposomes loaded with 0% or 10% w/w Tween 20 gave a release of 59.8 ± 1.2 % and 74.0 ± 1.8 % respectively. This indicates a compounds individual physiochemical properties influences release of compound from liposomes. EGCG, naringenin and MTL-004 loaded liposomes added into the aqueous gel HEC or HPMC gels may have had an additive effect in terms of retarding drug release. Release was faster from HEC gels and liposomes formulated with Tween 20. In vitro cellular uptake of liposome uptake into HDFa and HaCat cells was apparent. Thus it appears elastic liposomes are useful in enhancing drug penetration into dermal cells and furthermore may be useful in the development of a controlled release formulation.

Professionalism has often been a difficult concept to define or describe but researchers agree that it is an important trait to maintain professional status within society. Professional status is attained through a process of professionalisation, it can be lost through a process of deprofessionalisation and can be re-attained through reprofessionalisation. Despite being considered a profession by some researchers, others have argued that pharmacy has failed to fully professionalise with some labelling it a ‘quasi-profession’. Some scholars believe that the future of community pharmacy may rely on service provision and that this is essential to reprofessionalise pharmacy. Given the uncertainty of current professional status, a mixed methods approach was used to explore the views and opinions of the general public, pharmacists and pharmacy leaders on matters relating to professional status. The thesis presents three studies: a qualitative study with pharmacy leaders; a mixed methods study comprising a questionnaire with members of the general public in England and a further mixed methods study comprising a questionnaire with pharmacists. The qualitative study with pharmacy leaders gave an insight into pharmacy leaders’ views and opinions relating to public understanding of pharmacy, professionalism and professional status. This informed the development of the questionnaires used for the subsequent two studies. The questionnaires identified differing public understanding and opinions on pharmacists and matters relating to professional status. Differences were also identified between the general public and pharmacists on these matters. Finally, the qualitative stage offered further exploration and clarification of findings discovered from the questionnaire data. Recommendations about understanding current public opinion of pharmacists may help further clarify the current professional status of community pharmacy.

Orally dissolving films (ODFs) have received much attention as potential delivery systems for oral administration of drugs to paediatric patients. With their unique properties and advantages, the technology offers improved patient compliance and wider acceptability, eliminated fear of choking, ease of administration and dosing convenience,without the requirement of water. This research focused on the formulation of ODFs with suitable physico-chemical and clinical properties as a potential dosage form for paediatric use. Initial studies focused on screening different film-forming materials used for the preparation of orally dissolving films in order to optimise and propose suitable polymers and plasticisers with a suitable manufacturing technique. Kollicoat Protect was a selected candidate for further studies, due to its excellent film forming capacity with rapid disintegration. The work also sought to improve the loading capacity, taste masking and drug content uniformity of both hydrophilic (dexchlorpheniramine malate) and hydrophobic(glipizide) drugs into ODFs, especially for poorly water soluble drugs, through complexation with cyclodextrins (CDs) and incorporation with nanoparticles. Results demonstrated that CD complexation showed improvement in the solubility profile of glipizide, whilst drug loading efficiency and drug content uniformity only improved at low doses, based on the limited cavity sizes. Nonetheless, the application of nanoparticles achieved good drug loading efficiency for glipizide at higher doses. In contrast, the loading capacity and other physico-chemical properties of dexchlorpheniramine maleateloaded films remain flexible. Further, method development to optimise the determination of disintegration time of ODFs proved that the media and media volume has no effect on disintegration time using either beaker or the texture analyser method, but the analyser method demonstrated to be more suitable for quality control setting of ODFs. Of the stability performance of ODFs, films packed with the prototype packaging remained stable over the period of time studied at both long term and accelerated conditions, which indicated their robust and clinical use through the product developmental stages.

A third of epilepsy patients are resistant to anti-epileptic drug (AED) treatment leading to reduced quality of life, increased treatment costs and complexities surrounding polytherapy. The overall aim of this project was to explore dynamic network changes in the excitability and efficacy of AEDs in: acute models of epileptiform activity, chronic models of epileptogenesis and in resected human tissue, in vitro. Initial studies investigated the differences in the neuronal network excitability induced by 0[Mg]2+ in rat brain slices prepared using either a standard NaCl-based aCSF or a sucrose-based aCSF. Standard prepared slices were more excitable in comparison to sucrose-based aCSF prepared slices. Immunohistochemical investigations for parvalbumin demonstrated a reduction of interneurons in slices prepared in the standard way. There was little difference in response to combination AEDs, but this could be due to increased latency to first seizure in sucrose prepared slices. LTP was suggested to play a role in the resistance to AEDs. These results suggest sucrose prepared slices better preserve the neuronal network in vitro, and serve as a better acute model for assessing AEDs and mechanisms of resistance. Sucrose perfused slices were prepared from rodents that had undergone a refined chronic Li-pilocarpine-based model of epileptogenesis (RISE) to investigate the effects of six AED combinations on network excitability (24 hrs and 1, 5 and 12 weeks post status). Ictal-like discharges (IDs) were seen in significantly greater numbers in slices from RISE animals compared to age-matched controls. Additionally, RISE slices showed a consistently shorter latency to first seizure across all time points. Investigations exploring the efficacy of different AED combinations during epileptogenesis showed that the tiagabine and carbamazepine combination was most effective in reducing measures of ictal activity whilst the combination of lamotrigine and gabapentin was least effective. The resistance of different drug combinations was also variable depending on the stage of epileptogenesis. These findings suggest that vulnerable networks show underlying hyperexcitability even at stages when chronic behavioural seizures are not yet developed, and that the RISE model may provide insights into the variable efficacy of AEDs. In comparison to chronically epileptic rodent tissue, epileptic human tissue from the temporal lobe was not as excitable, and often required stronger ID inducing manipulations. Once IDs were initiated in vitro, inter-event intervals between seizures were longer in comparison rodent epileptic tissue. Discrepancies in excitability could be attributed to the likelihood that damage within human tissue is likely to be subtle, hence require more stimulation to induce ictal-like activity (Gabriel et al., 2004). There was a developmental trend for excitability, in response to low concentrations of the NMDA antagonist MK801 (100-300 nM), to decrease in controls and remain elevated in epileptic animals. The NOS inhibitor, 7-nitraindazole, failed to stop the induction of IDs by low concentrations of MK801. Additionally, low concentrations of MK801 had no significant effects on the frequency and amplitude of field IPSPs in control and SE latent period slices. Further investigations are required to elucidate the mechanisms of how altered excitatory drive of inhibition may promote network excitability in epilepsy Overall, my findings suggest network changes in excitability occur at stages when chronic behavioural seizures are not yet developed, and that the RISE model may provide insights into the variable efficacy of AEDs and underlying mechanisms of epileptogenesis.

Given the great potential of porous carrier based drug delivery for stabilising the amorphous form of drugs and enhancing dissolution profiles, this thesis centred on investigations into the application of activated carbon (AC) and carbon onion (OLC) as porous carriers for oral delivery, using paracetamol (PA) and ibuprofen (IBU) as model drugs. Initial work was focussed on the toxicity studies of AC followed by preparation and characterisation of drug/AC complex. Results showed that AC is a promising drug carrier with low toxicity, high loading capacity and ability to stabilise amorphous drug. However, loading efficiency and solid state characteristics were different for PA and IBU, whilst the drug release from AC was incomplete in the absence of surfactant. To investigate the factors affecting drug loading, three different loading methods were compared, with solution adsorption followed by centrifugation found to be the optimum method to achieve maximum loading with least crystallinity. Initial drug concentration in the loading solution was also found to influence the loading, where the optimum concentration to achieve maximum loading without any crystallinity differed depending on the chemical nature of the drug. Further, the surface chemistry of AC was modified in order to achieve complete drug release, and results showed that drug release increased with an increase in the surface oxygen content of AC. Also, drug release was found to increase with a decrease in the micropore volume fraction. The second part of the work was focussed on the synthesis and characterisation of OLC, followed by drug loading studies. Results showed that annealing of nano-diamonds (ND) at 1100 oC produced OLC with a diamond core, which is non-toxic. Drug loading studies revealed that loadings achieved were lower than those seen with AC, regardless of drug solubility. Of the both carriers investigated, AC was less expensive and found to be a promising carrier with higher loading capacity and lower toxicity.

Antipsychotic medications are associated with an increased risk of falls, delirium and cerebrovascular events; and all can cause death (1-7). It is crucial that patients prescribed these agents receive regular specialist review to optimise therapy and prevent harm (8, 9). When antipsychotic prescribing in an acute hospital was investigated, it was found that only a third of patients on these agents were reviewed by the hospitals psychiatry team (8, 10, 11). A novel pharmacist referral system was developed to establish whether pharmacy could help improve patient’s access to psychiatric services to facilitate medication review. 345 patients (44%, n=345) were reviewed by a pharmacist and 152 (44%) referrals made. Nearly half (n=69, 20%) of the referrals were generated by a pharmacist using the newly implemented system. Pharmacy referrals focussedon medication safety, this was different to those generated by medical staff whose emphasis was on symptoms and behaviour. In addition to referrals the pharmacists were found to have a clinical impact on patient care in an additional 91 (26%) patients. The adverse consequences (ADRs) of antipsychotics were implicated in 45 patient admissions, confirming the real potential for patient harm. The pharmacist referral system identified the majority (n=39, 87%) of the ADRs. Following psychiatry review, 69% (n=31) of patient’s medication was adjusted following mental health assessment where both the patient’s mental and physical health needs were considered. The pharmacy referral service was found to enhance the clinical management of the vulnerable mental health patient in the hospital setting. It was an alternative to the traditional model of pharmacy in which clinical pharmacy services were targeted according to patient need rather than by physical ward location. Although, the model was demonstrated in mental health, it is felt that it could have a wider use according to the prescription of any high-risk medication.

Epilepsy is a common and serious neurological disorder, which manifests in seizures, and has an incidence of approximately 1% of the world population. In developed nations, most instances are relatively well controlled through the use of anti-epileptic drugs (AEDs). For around a third of cases, AEDs are ineffective, resulting in poorly maintained seizures otherwise known as refractory, or drug-resistant epilepsy (DRE). Currently, treatment of DRE often requires neurosurgery to be performed to resect seizure generating foci. Historically, such treatment was used as a last resort due to the invasive and higher risk nature of neurosurgery. More recently, however, surgical intervention has been performed much earlier in order to achieve better long-term patient outcomes. Notwithstanding this, DRE presents a major and as of yet, unmet clinical need for new and effective antiepileptic drugs to be found. In vitro and in vivo electrophysiological methods have been used investigate epilepsy for many years. Neuronal network oscillations and single cell patching recordings between physiological and pathophysiological samples provide a basis to compare alterations between normal and epileptic brain tissue. In terms of electrophysiological approaches, the hippocampus and entorhinal cortex (EC) are two of the most commonly studied areas of the brain, especially in relation to temporal lobe epilepsy (TLE). Plant derived cannabinoids – phytocannabinoids – have been proposed as effective AEDs for DRE cases. In particular the non-psychoactive phytocannabinoids cannabidiol (CBD) and cannabidivarin (CBDV), with recent clinical trials supporting this claim. The present study is an investigation into whether CBD and CBDV are suitable and effective AEDs, and to identify their mechanism(s) of action. Electrophysiological recordings of medial entorhinal cortex (mEC) layer II principal cells have been studied due to their relative importance and participation in TLE. Alterations in oscillatory rhythms and single cell responses were compared between RISE afflicted epileptic rats (SE rats) and wild type, age matched controls (AMC). Experiments on human tissue resected from children with TLE were also performed, concurrent with the rodent experiments. Key findings from this project show CBD(V) suppressant effects on induced gamma oscillations, in an age- and disease-dependent manner in rat tissue, suggesting damping of neuronal network excitability. Further to this, CBD induces increased GABA inhibition onto rat medial entorhinal principal cells as evidenced by increases in mean median decay times and inhibitory charge transfer across the postsynaptic membrane, while CBDV did not show this effect. The effects of CBD were effectively blocked by both GABAAR and NMDAR antagonists, suggesting interaction with both of these receptors to exert the response. CBD also showed additive effect to low-dose benzodiazepine and barbiturate agonists and a ceiling effect at higher doses, suggestive of an allosteric action on the GABAAR. Similar effects were also noted in the human tissue cells, suggestive of an analogous mechanism of action in humans. Hence, we postulate that CBD is acting at both postsynaptic GABAARs, as a positive allosteric modulator (PAM) and, at pre-/postsynaptic NMDARs, either directly or indirectly, to positively influence GABA signalling mechanisms causing an increase in inhibitory activity at postsynaptic principal cells resulting in decreased neuronal excitability.

New molecular entities entering the pharmaceutical market are required to adhere to stringent safety, efficacy and quality requirements that often lead to delays in the early-phases of drug development. Pharmacokinetic modelling approaches, such as physiologically-based pharmacokinetic (PBPK) modelling, can cater to most of the critical PK issues and at the same time optimise the utilising of resources. The overall aim of this work was to illustrate, explore and facilitate the application of PBPK modelling in the context of drug disposition and risk assessment. In Chapter 2 of this thesis, we illustrated the concept of developing customisable pharmacokinetic models through the development of a region-specific CNS PBPK model to assess the rodent hippocampus and frontal cortex pharmacokinetics using MATLAB. We then extrapolated the model to predict human regional brain pharmacokinetics, using morphine as a case study for comparison. This successfully proposed a simplified first-principle approach to the development of a regional brain central nervous system (CNS) PBPK model. This approach has significant implications for assessing drug disposition across the human CNS and provides an opportunity for exploring the relationship between regional brain drug concentration, pharmacodynamics effects, and interspecies extrapolation. In Chapter 3 of this thesis, our goal was to develop a population-based PBPK modelling that could explore the potential risk of drug-drug interactions (DDIs) in adults and paediatric populations. We developed a model capable of predicting the impact of efavirenz-mediated DDIs on thepharmacokinetics of the antimalarial drug lumefantrine in Ugandan paediatric population groups,whilst also accounting for the polymorphic nature of CYP2B6. We demonstrated that an extension of the current artemether-lumefantrine treatment regimen from 3-days to 7-days would counteract the reduction in efavirenz metabolism common with the *6/*6 genotype and hence enhance the attainment of the target day-7 lumefantrine concentration in both *1/*1 and *6/*6 genotype groups, thereby reducing the risk of malaria parasite recrudescence. This study demonstrated the capability of PBPK modelling in predicting PK profiles in special population such as paediatrics and dealing with complex DDIs associated with genotype specific effects. The final part of this work, Chapter 4, focussed on demonstrating the capability of PBPK modelling in addressing inter-ethnicity variability and risk assessments within a mixed population group. We explored the application of PBPK models for specific population data analyses in the context of CYP2C19 polymorphism on clopidogrel in the multi-ethnic populations of Malaysia. We demonstrated a statistically significant difference in the peak concentrations of the active metabolite, clopi-H4, between the extensive metaboliser (EM) and poor metaboliser (PM) phenotypes with either Malay or Malaysian Chinese population groups. The study directly addresses this inter-ethnicity variability and provide a research tool that brings together the complexity of systems-biology with the ease-of-use applicability of pharmacokinetic modelling to provide a robust predictive platform which can easily be adapted and developed as required within a population.