In the pulmonary circulation voltage-gated K+ (KV) channels control resting membrane potential. Their direct contribution to the development of hypoxic pulmonary vasoconstriction (HPV), the unique response of the pulmonary artery (PA) to hypoxia, however remains controversial. KCNQ channels are thought to contribute to the control of PA excitability but their relative contribution compared to the KV channels and the role in HPV is unknown. Recent electrophysiological evidence suggests tight coupling between KV channels and mitochondria, a putative oxygen sensor in PA. No focussed studies to examine these questions in intact arteries were performed. Therefore, the main aims were to investigate: i) a relative role of KV and KCNQ channels in the regulation of PA excitability and contractility, ii) relative sensitivity of these channels to hypoxia, iii) a relationship between KV channels and mitochondria and cellular metabolism, in the intact PA. Rat mesenteric artery (MA) was used as a representative of systemic circulations. Small vessel myography, microelectrode technique, confocal imaging and western blot together with selective pharmacological agents were employed to address these questions. The main findings are: i) the presence of mutual physiological interaction between KV and KCNQ channels in the regulation of PA excitability, ii) KV, but not KCNQ, channels are inhibited by hypoxia in PA, iii) the existence of specific interactions between mitochondria and KV channels which are potentiated and altered in hypoxia in PA, not in MA, iv) these interactions may contribute to contractions caused by the KV inhibition 2+ 2+ additionally to the voltage-dependent Caentry and Rho-kinase dependent Casensitisation, v) contractions are less metabolic dependent in PA than in MA, vi) the effects are not species dependent as some were observed in the mouse. These findings suggest the presence of specific mitochondrial-dependent mechanisms in PA which play role in physiological conditions and in HPV.

No description available.

The physicochemical properties and surface chemistry of orally inhaled active pharmaceutical ingredients (API) are critical to the quality attributes of dry powder inhaler (DPI) formulations. The requirement to reduce the particle size distribution of the APIs to a respirable range, largely performed through air-jet micronisation, imparts large amounts of energy to the drug particles, which together with particle fracture and size reduction, it is accompanied by the generation of structural defects and, at the limit, the formation of amorphous regions. This is known as mechanical activation, which may cause instability in the physicochemical properties and interfacial chemistry at the particle surface as it undergoes structural relaxation. During the thermodynamically driven relaxation process, differing drug properties may lead to DPI formulations with unpredictable formulation structure and product functionality. A fundamental understanding of the structural relaxation dynamics is therefore essential in the development and commercialisation of a quality-by-design led inhalation product. This thesis investigated the structural relaxation dynamics of micronised fluticasone propionate (FP), salmeterol xinafoate (SX) and glycopyrrolate bromide (GLY). Physicochemical properties and surface interfacial chemistry, via cohesive-adhesive balance (CAB) measurements, of micronised drug are assessed as a function of environmental stressed laagering over well-defined periods of time and in situ conditioning in hydrofluoroalkane (HFA). The influence of these dynamics upon DPI performance was also examined in both binary (FP, SX, GLY) and tertiary formulations (FP-SX). The results indicated how structural relaxation of hydrophobic and hydrophilic APIs trigger off different stress relaxation pathways with different sensitivities to laagering conditions. These data suggested that the introduction of a post-micronisation conditioning step may expedite structural relaxation of hydrophobic APIs. Whilst the physical properties of hydrophobic APIs are largely unaffected by mechanical activation, surface interfacial chemistry governing inter-particulate forces between API and the lactose carrier is directly affected by environmental conditions of temperature and relative humidity during structural relaxation. The study also showed the potential use of post-micronisation conditioning to tailor the surface chemistry properties of APIs. For hydrophilic APIs, data suggested that post-micronisation conditioning is essential in enabling physical and chemical stability of inhaled formulations. Furthermore, in vitro aerosolisation studies suggested that the aerodynamic particle size distribution and fine particle mass were directly affected by post-micronisation laagering conditions. The importance of generating a well defined, understood and controlled design space throughout product development dictates the need for more robust API processing prior to DPI formulation. This work highlights how a tailored post-micronisation laagering strategy can have a significant effect on physicochemical and interfacial properties as well as product performance of binary and tertiary carrier based DPI formulations.

Introduction: The use of guidelines in prescribing has become part of clinical practice in many countries around the world. Guidelines are considered to provide information based on scientific evidence from high quality research and hence are expected to lead to appropriate prescribing. Prescribing based on evidence is expected to improve morbidities and mortalities. Pharmacists in different parts of the world are acquiring a clinical professional identity especially in hospital settings where they have moved to bed-side roles to become an effective member of the patient–care team. They are thus expected to play an important role in assisting appropriate prescribing and have a positive impact on patient care. The influence of guidelines on prescribing and the practice of clinical pharmacy have not been studied in Sudan. Aim: The aim of the study was to investigate the use of guidelines (if any) for prescribing by doctors in the main cardiac hospitals in Sudan, and to explore the influence of availability (or non-availability) of guidelines on the new role of clinical pharmacy in hospitals in Sudan. Method: The study used a mixed method approach to examine the study questions. Interviews were conducted with the cardiology consultants in two of the main cardiac hospitals in Sudan. This was followed by a survey among all the doctors in the hospitals. Later on a focus group discussion was carried out with clinical pharmacists in the two hospitals followed by an online survey sent to the available email addresses of clinical pharmacists in Sudan. Results: Twelve prescribers were interviewed and 47 prescribers (60%) replied to the questionnaire that followed. The majority of the doctors relied on foreign guidelines to prescribe for their patients. The doctors acknowledged the limitation of using foreign guidelines in Sudan. Few prescribers were not in favour of following any guidelines as they perceived that the practice in Sudan does not allow implementation of guidelines. The prescribers were positive about the new role of clinical pharmacists in patient care but they seem not to be in contact with these clinical pharmacists. On the other hand, four pharmacists participated in one focus group and 51(34%) completed the on-line survey. Clinical pharmacists faced a number of obstacles that hindered their progress in practice and the unavailability of guidelines was considered to be one of these obstacles. Other obstacles were related to the pharmacists themselves, to the lack of senior clinical pharmacists for leadership, to the environment they were working in and to the training they received in clinical pharmacy. Conclusion: The making of guidelines is usually a tedious and costly process. Medical practice in places with limited resources has to rely on guidelines made in foreign countries if they want to get the benefits of these guidelines to their patients. The prescribers in Sudan had to find a way to adapt foreign guidelines to their patients and to the healthcare system they are working within. With regard to the clinical pharmacists in Sudan, they are faced with a number of obstacles that they will have to overcome in order to advance in their new role. The new clinical pharmacists will have to be the leaders to pave the way for clinical pharmacy in Sudan. However, they will require support from pharmacy educational institutions, other healthcare professionals and healthcare institutions.

The mode of action of glyphosate has been studied with a variety of plant material. Chlorophyll formation was particularly sensitive, but was unlikely to be due to an interference with chloroplast macromolecule synthesis. Protein and RNA synthesis by isolated chloroplasts were not inhibited in vitro although chlorotic growth contained reduced levels of rRNA. The induction of nitrite reductase, a chloroplast protein was repressed in peas but not to an extent which would suggest inhibition of de novo synthesis. The induction of nitrate reductase was stimulated, but this was only transitory. Effects of glyphosate could not be negated by metal ions or glycine. Glyphosate inhibited the growth of both single node buds of Agropyron rhizome and wheat roots. 14C-glyphosate administered to single nodes was recovered from the buds principally unchanged and did not bind to cell walls or a protein/nucleic acid fraction. A metabolite was present, representing 10% of total 14C-activity. The syntheses of DNA, RNA and cellulose were inhibited to similar extents, due partly to inhibition of 14C-precursor uptake, notably in the case of DNA synthesis. The incorporation of 14C-leucine was inhibited markedly but that of 14C-phenylalanine was not greatly affected whereas the incorporation of 14C-protein hydrolysate was inhibited to an intermediate extent. These results indicated an inhibition of protein synthesis brought about by a diminution of the phenylalanine protein precursor pool. The induction of phenylalanine ammonia-lyase (PAL) was enhanced markedly in both single node buds and wheat root tips. In the latter case this was accompanied by declines in soluble protein and the rate of formazan reduction. Growth inhibition could not be alleviated by exogenous L-phenylalanine, mixed aromatic amino acids or PAL inhibitors. The specific activities of shikimic acid pathway enzymes, polyphenol oxidase and some hydrolytic enzymes characteristic of senescence were also enhanced. A 'classic wound response' was not elicited as the evolution of ethylene was not activated. The generation of ethane, however, an indicator of oxidative membrane lipid breakdown was stimulated, but the specific activities of microsomal marker enzymes were unaffected. Levels of these enzymes declined due to a reduction in the amount of microsomal protein present. Microsomal ATPases were not inhibited in vitro by glyphosate. The toxicity of glyphosate would appear to be mediated at least partly by a decrease in free phenylalanine resulting in inhibition of protein synthesis and de-repression of PAL. The involvement of other factors is not excluded.

The pharmaceutical analysis of illicit drugs and the associated impurity profiling can contribute to a harm reduction approach. Impurities in illicit drugs represent a complex problem that requires detailed and reproducible analysis, in part because cutting agents are not often reported by the forensic science community. This research project is focussed on characterising Novel Psychoactive Substances (NPS) and determining their purity/impurity (adulteration) employing a wide range of spectroscopic and chromatographic methods, mainly NMR spectroscopy and Mass Spectrometry. Another aim is to develop a routine, rapid, and quantitative analytical protocol to identify illicit drugs and their impurities (cutting agents) in seized street samples. These two major aims were achieved. A comprehensive, but critical review of the current literature is provided with respect to the analytical chemistry aspects of illicit drugs and especially their cutting agents. This literature review has a focus on the global concern arising from the current and continuing emergence of NPS and their diverse public health effects. Evidence is provided of illegal drugs, mainly so-called “legal highs” (NPS), from detailed analysis of the contents of amnesty bins and their adulterants provided by the Police from a Bristol night club and from the 2013 Glastonbury music festival, besides other samples they had seized. An accurate chemical assignment of flephedrone regioisomers is made and compared with mephedrone. Impurity profiling of street mephedrone and ketamine samples and their adulterants is presented. A possible link between mephedrone samples is investigated by applying PCA and HCA statistical methods to the 1H NMR data.

A novel class of lipid formulation was investigated comprising GRAS (generally regarded as safe) materials. The formulations were all ‘surfactant-free’ (S-F) formulations, and also referred to as ‘Type IV’ lipid formulations. These formulations were isotropic, transparent, thermodynamically stable at room temperature and typically composed of > 50 % of mixed mono-, di- and triglycerides, > 30 % medium chain fatty acids oil and < 20 % hydrophilic co-solvent. At equilibrium, S-F formulations enhanced the solvent capacity of corticosteroids (log P > 3) and hydroxy benzoate derivatives over type II SEDDS and type III SEDDS, but generally were not superior solvents to mixtures of mono-, di- and triglycerides (Imwitor 988® and or Capmul MCM®) alone, for lipophilic steroids (log P < 3). In general, type III SEDDS which were composed of high hydrophilic content (hydrophilic surfactant, HLB > 1 2 , and hydrophilic co-solvent), were also better solvents for most steroidal compounds and hydroxy benzoate derivatives than type II SEDDS and type I SEDDS formulations. Surfactant with HLB > 12 inhibited lipolysis of MCT and mixed glycerides when the concentration of surfactant exceeded 40 % w/w. Hydrophobic surfactants (HLB < 10) did not inhibit lipolysis. Thus, the digestibility of dispersions formed by selfemulsifying systems would be dependent on the surfactants used and the quantity of TG available for lipolysis. Co-solvents did not appear to influence lipolysis, once the formulations had dispersed. Phase separation of lipid formulations following their dispersion in simulated intestinal fluid was studied. The lipid formulation behaviour was dependent on monoglyceride content. When sufficient monoglyceride (> 60 %w/v) was present demulsification and phase separation was noticed and was found to be dependent on the presence of phospholipid. This resulted in sedimentation of the phase rich V monoglyceride and water. The presence of triglyceride stabilised the formation of mixed micelles, which remained in a finely dispersed state. This unexpected phase separation is likely to have a considerable effect on the fate of drug dissolved in SEDDS formulations. The high concentrations of monoglyceride may be disadvantageous and could possibly result in precipitation of drug.

1. A radioimmunoassay was established for the measurement of anti-(acetylcholine receptor) antibodies in the serum of myasthenic patients. It was found that 87% of myasthenic serum samples contained elevated levels of circulating anti-(acetylcholine receptor) antibody but that there was no direct correlation between the antibody titre and disease severity. Also, the anti-(acetylcholine receptor) antibody titre was measured in a series of patients that underwent a course of plasma exchange. The antibody titre was found to decrease following plasma exchange and the majority of patients obtained complete clinical remission for periods of up to 18 months following the completion of exchanges. 2. The nicotinic acetylcholine receptor protein has been purified from human skeletal muscle by a procedure involving extraction in non-ionic detergent followed by affinity purification on immobilised a toxin. Purified receptor preparations had specific activities of 0.5-3.5mumol a bungarotoxin binding sites per gram protein and sedi-mented as a single 125I-alpha bungarotoxin-binding species in sucrose density gradient centrifugation with S20,w =9.5. The purified protein focussed as a single sharp band at pH 6.6 when labelled directly with 125I and at pH 5.1 when complexed to 125I-alpha bungarotoxin. Polyacrylamide gel electrophoresis under non-denaturing conditions of receptor-toxin complex showed a single protein component of similar mobility to that of acetylcholine receptor from Torpedo marmorata, whilst polyacrylamide gel electrophoresis of the purified receptor under denaturing conditions showed two major protein bands with molecular weights 42000 and 66000 respectively with the occasional appearance of minor components at 56000 and 85000. Only the 42000 subunit was labelled with the affinity reagent, [3H]-MBTA. The purified receptor bound 125I-alpha bungarotoxin and d-tubo-curarine with kD values of 0.5nM and 0.25muM respectively. It behaved similarly to impurified detergent-extracted human receptor in the radioimmunoassay for anti-(human acetylcholine receptor) antibodies and when injected into rabbits caused increased levels of the latter antibodies but did not cause experimental autoimmune myasthenia gravis.

The main aim of this work was to investigate the role of central cholinergic mechanisms in the control of behaviour. Three strains of rat, which display behavioural differences, were chosen for use in the work, these were the Roman High Avoidance (RHA) and the Roman Low Avoidance (RLA) strains, with the Porton strain to act as a reference line. Differences in conditioned avoidance behaviour and spontaneous activity were demonstrated between the strains and also in their behavioural response to drugs known to affect the central cholinergic system. These were, an anti-acetylcholine drug, N-ethyl-3-piperidyl benzilate which produced hyperactivity and facilitated avoidance conditioning, an anti-cholinesterase drug, physostigmine, which depressed spontaneous activity and conditioned avoidance behaviour. No change in behaviour of any of the strains was seen after treatment with drugs thought to have mainly peripheral actions on the cholinergic system. These drugs were N-ethyl-3-piperidyl benzilate methiodide and pyridostigmine. Strain differences were also seen in response to an adrenergic drug, d-Ampheta-mine. Facilitated behavioural performance was seen after a combination of anti-acetylcholine and adrenergic drugs were given to rats, which when given separately, at the same doses, produced no effect on behavior. Determination of acetylcholine concentration and cholinesterase activity in discrete brain areas revealed differences in the former but not the latter activity, implying that differences also exist between the strains in enzyme to substrate ratios. The support these findings give to theories of cholinergic inhibition in the control of behaviour and to the idea that behavioural control results from the central interaction of cholinergic and adrenergic transmitter systems is discussed. The value of selectively bred strains as tools in psychopharmacology is also assessed in the light of this work.

The principal objective of this work was to investigate the possibility that the effects of a number of drugs on conditioned avoidance behaviour of the laboratory rat, could be attributed to an action(s) on the functioning of catecholamine-containing neurons of the amygdala. In order to restrict drug action to the amygdala, a cannula-guide system was prepared and fixed to the skull of the experimental animal prior to behavioural observation. Drug solutions were injected into the vicinity of the nucleus amygdaloideus centralis in conscious, unrestrained rats, through an injection cannula passed down the guide tube. The effects of drugs administered by this route on the acquisition of the pole-climb conditioned avoidance response were observed. Low doses of d-amphetamine, apomorphine and benztropine applied to the amygdala, resulted in facilitated acquisition of the conditioned response over the five days of training. Higher doses disrupted this behaviour. Haloperidol and pimozide, two competitive antagonists of dopamine, and desmethylimipramine, a potent blocker of noradrenaline re-uptake, decreased the rate of acquisition of the conditioned response. The disruptive effects of the high dose of d-amphetamine and of desmethyl-imipramine were reversed by the alpha-adrenoreceptor blocking drug phentolamine. Application of dopamine and noradrenaline increased and decreased respectively, the rate of acquisition of the conditioned response. The results are discussed in relation to the proposed mechanism of action of these drugs at the synapse and how they might modify nervous activity. Proposals have been made regarding the functional significance of catecholamine-containing neuron systems of the amygdala in conditioned avoidance behaviour. Suggestions for further research have also been made.