The roughness and imaging characterisation of different pharmaceutical surfaces

The surface properties of solid state pharmaceutics are of critical importance. Processing modifies the surfaces and effects surface roughness, which influences the performance of the final dosage form in many different levels. Surface roughness has an effect on, e.g., the properties of powders, tablet compression and tablet coating. The overall goal of this research was to understand the surface structures of pharmaceutical surfaces. In this context the specific purpose was to compare four different analysing techniques (optical microscopy, scanning electron microscopy, laser profilometry and atomic force microscopy) in various pharmaceutical applications where the surfaces have quite different roughness scale. This was done by comparing the image and roughness analysing techniques using powder compacts, coated tablets and crystal surfaces as model surfaces. It was found that optical microscopy was still a very efficient technique, as it yielded information that SEM and AFM imaging are not able to provide. Roughness measurements complemented the image data and gave quantitative information about height differences. AFM roughness data represents the roughness of only a small part of the surface and therefore needs other methods like laser profilometer are needed to provide a larger scale description of the surface. The new developed roughness analysing method visualised surface roughness by giving detailed roughness maps, which showed local variations in surface roughness values. The method was able to provide a picture of the surface heterogeneity and the scale of the roughness. In the coating study, the laser profilometer results showed that the increase in surface roughness was largest during the first 30 minutes of coating when the surface was not yet fully covered with coating. The SEM images and the dispersive X-ray analysis results showed that the surface was fully covered with coating within 15 to 30 minutes. The combination of the different measurement techniques made it possible to follow the change of surface roughness and development of polymer coating. The optical imaging techniques gave a good overview of processes affecting the whole crystal surface, but they lacked the resolution to see small nanometer scale processes. AFM was used to visualize the nanoscale effects of cleaving and reveal the full surface heterogeneity, which underlies the optical imaging. Ethanol washing changed small (nanoscale) structure to some extent, but the effect of ethanol washing on the larger scale was small. Water washing caused total reformation of the surface structure at all levels.

Molecular genetic studies on nemaline myopathy and related disorders

Nemaline myopathy (NM) is a rare muscle disorder characterised by muscle weakness and nemaline bodies in striated muscle tissue. Nemaline bodies are derived from sarcomeric Z discs and may be detected by light microscopy. The disease can be divided into six subclasses varying from very severe, in some cases lethal forms to milder forms. NM is usually the consequence of a gene mutation and the mode of inheritance varies between NM subclasses and different families. Mutations in six genes are known to cause NM; nebulin (NEB), alpha-actin, alpha-tropomyosin (TPM3), troponin T1, beta-tropomyosin (TPM2) and cofilin 2, of which nebulin and -actin are the most common. One of the main interests of my research is NEB. Nebulin is a giant muscle protein (600-900 kDa) expressed mainly in the thin filaments of striated muscle. Mutations in NEB are the main cause of autosomal recessive NM. The gene consists of 183 exons. Thus being gigantic, NEB is very challenging to investigate. NEB was screened for mutations using denaturing High Performance Liquid Chromatography (dHPLC) and sequencing. DNA samples from 44 families were included in this study, and we found and published 45 different mutations in them. To date, we have identified 115 mutations in NEB in a total of 96 families. In addition, we determined the occurrence in a world-wide sample cohort of a 2.5 kb deletion containing NEB exon 55 identified in the Ashkenazi Jewish population. In order to find the seventh putative NM gene a genome-wide linkage study was performed in a series of Turkish families. In two of these families, we identified a homozygous mutation disrupting the termination signal of the TPM3 gene, a previously known NM-causing gene. This mutation is likely a founder mutation in the Turkish population. In addition, we described a novel recessively inherited distal myopathy, named distal nebulin myopathy, caused by two different homozygous missense mutations in NEB in six Finnish patients. Both mutations, when combined in compound heterozygous form with a more disruptive mutation, are known to cause NM. This study consisted of molecular genetic mutation analyses, light and electron microscopic studies of muscle biopsies, muscle imaging and clinical examination of patients. In these patients the distribution of muscle weakness was different from NM. Nemaline bodies were not detectable with routine light microscopy, and they were inconspicuous or absent even using electron microscopy. No genetic cause was known to underlie cap myopathy, a congenital myopathy characterised by cap-like structures in the muscle fibres, until we identified a deletion of one codon of the TPM2 gene, in a 30-year-old cap myopathy patient. This mutation does not change the reading frame of the gene, but a deletion of one amino acid does affect the conformation of the protein produced. In summary, this thesis describes a novel distal myopathy caused by mutations in the nebulin gene, several novel nebulin mutations associated with nemaline myopathy, the first molecular genetic cause of cap myopathy, i.e. a mutation in the beta-tropomyosin gene, and a founder mutation in the alpha-tropomyosin gene underlying autosomal recessive nemaline myopathy in the Turkish population.

Physical characterization of plastic surfaces in wearing and cleanability research

Plastic surfaces are a group of materials used for many purposes. The present study was focused on methods for investigation of surface topography, wearing and cleanability of polyvinyl chloride (PVC) model surfaces and industrial plastic surfaces. Contact profilometry, scanning electron microscopy (SEM) and atomic force microscopy (AFM) are powerful methods for studying the topography of plastic surfaces. Although they have their own limitations, they are together an effective tool providing useful information on surface topography, especially when studying laboratory-made PVC model surfaces with known chemical compositions and structures. All examined laboratory-made PVC plastic surfaces examined in this work could be considered as smooth according to both AFM and profilometer measurements because height differences are in the nanoscale on every surface. Industrial plastic surfaces are a complex group of materials because of their chemical and topographical heterogeneity, but they are nevertheless important reference materials when developing cleaning and wearing methods. According to the results of this study the Soiling and Wearing Drum and the Frick-Taber methods are very useful when simulating three-body wearing of plastic surfaces. Both the investigated wearing methods can be used to compare the wearing of different plastic materials using appropriate evaluation methods of wearing and industrial use. In this study, physical methods were developed and adapted from other fields of material research to cleanability studies. The thesis focuses on the methodology for investigating the cleanability of plastic surfaces under realistic conditions, where surface topography and the effect of wear cleanability were among the major topics. A colorimetric method proved to be suitable for examining the cleanability of the industrial plastic surfaces. The results were utilized to evaluate the relationship between cleanability and the surface properties of plastic surfaces. The devices and methods used in the work can be utilized both in material research and product development.

Mannans as film formers and emulsion stabilizers

Mannans are abundant plant polysaccharides found in the endosperm of certain leguminous seeds (guar gum galactomannan, GG; locust bean gum galactomannan, LBG), in the tuber of the konjac plant (konjac glucomannan, KGM), and in softwoods (galactoglucomannan, GGM). This study focused on the effects of the chemical structure of mannans on their film-forming and emulsion-stabilizing properties. Special focus was on spruce GGM, which is an interesting new product from forest biorefineries. A plasticizer was needed for the formation of films from mannans other than KGM and the optimal proportion was 40% (w/w of polymers) glycerol or sorbitol. Galactomannans with lower galactose content (LBG, modified GG) produced films with higher elongation at break and tensile strength. The mechanical properties of GG-based films were improved by decreasing the degree of polymerization of the polysaccharide with moderate mannanase treatments. The improvement of mechanical properties of GGM-based films was sought by blending GGM with each of poly(vinyl alcohol) (PVOH), corn arabinoxylan (cAX), and KGM. Adding other polymers increased the elongation at break of GGM blend films. The tensile strength of films increased with increasing amounts of PVOH and KGM, but the effect of cAX was the opposite. Dynamic mechanical analysis showed two separate loss modulus peaks for blends of GGM and PVOH, but a single peak for all other films. Optical and scanning electron microscopy confirmed good miscibility of GGM with cAX and KGM. In contrast, films blended from GGM and PVOH showed phase separation. GGM and KGM were mixed with cellulose nanowhiskers (CNW) to form composite films. Addition of CNW to KGM-based films induced the formation of fiberlike structures with lengths of several millimeters. In GGM-based films, rodlike structures with lengths of tens of micrometers were formed. Interestingly, the notable differences in the film structure did not appear to be related to the mechanical and thermal properties of the films. Permeability properties of GGM-based films were compared to those of films from commercial mannans KGM, GG, and LBG. GGM-based films had the lowest water vapor permeability when compared to films from other mannans. The oxygen permeability of GGM films was of the same magnitude as that of commercial polyethylene / ethylene vinyl alcohol / polyethylene laminate film. The aroma permeability of GGM films was low. All films were transparent in the visible region, but GGM films blocked the light transmission in the ultraviolet region of the spectra. The stabilizing effect of GGM on a model beverage emulsion system was studied and compared to that of GG, LBG, KGM, and cAX. In addition, GG was enzymatically modified in order to examine the effect of the degree of polymerization and the degree of substitution of galactomannans on emulsion stability. Use of GGM increased the turbidity of emulsions both immediately after preparation and after storage of up to 14 days at room temperature. GGM emulsions had higher turbidity than the emulsions containing other mannans. Increasing the storage temperature to +45 ºC led to rapid emulsion breakdown, but a decrease in storage temperature increased emulsion stability after 14 days. A low degree of polymerization and a high degree of substitution of the modified galactomannans were associated with a decrease in emulsion turbidity.

Capillary electrochromatography: a versatile instrumental technique for nanodomain interaction studies

This doctoral thesis describes the development of a miniaturized capillary electrochromatography (CEC) technique suitable for the study of interactions between various nanodomains of biological importance. The particular focus of the study was low-density lipoprotein (LDL) particles and their interaction with components of the extracellular matrix (ECM). LDL transports cholesterol to the tissues through the blood circulation, but when the LDL level becomes too high the particles begin to permeate and accumulate in the arteries. Through binding sites on apolipoprotein B-100 (apoB-100), LDL interacts with components of the ECM, such as proteoglycans (PGs) and collagen, in what is considered the key mechanism in the retention of lipoproteins and onset of atherosclerosis. Hydrolytic enzymes and oxidizing agents in the ECM may later successively degrade the LDL surface. Metabolic diseases such as diabetes may provoke damage of the ECM structure through the non-enzymatic reaction of glucose with collagen. In this work, fused silica capillaries of 50 micrometer i.d. were successfully coated with LDL and collagen, and steroids and apoB-100 peptide fragments were introduced as model compounds for interaction studies. The LDL coating was modified with copper sulphate or hydrolytic enzymes, and the interactions of steroids with the native and oxidized lipoproteins were studied. Lipids were also removed from the LDL particle coating leaving behind an apoB-100 surface for further studies. The development of collagen and collagen decorin coatings was helpful in the elucidation of the interactions of apoB-100 peptide fragments with the primary ECM component, collagen. Furthermore, the collagen I coating provided a good platform for glycation studies and for clarification of LDL interactions with native and modified collagen. All methods developed are inexpensive, requiring just small amounts of biomaterial. Moreover, the experimental conditions in CEC are easily modified, and the analyses can be carried out in a reasonable time frame. Other techniques were employed to support and complement the CEC studies. Scanning electron microscopy and atomic force microscopy provided crucial visual information about the native and modified coatings. Asymmetrical flow field-flow fractionation enabled size measurements of the modified lipoproteins. Finally, the CEC results were exploited to develop new sensor chips for a continuous flow quartz crystal microbalance technique, which provided complementary information about LDL ECM interactions. This thesis demonstrates the potential of CEC as a valuable and flexible technique for surface interaction studies. Further, CEC can serve as a novel microreactor for the in situ modification of LDL and collagen coatings. The coatings developed in this study provide useful platforms for a diversity of future investigations on biological nanodomains.

Development of analytical techniques for studies on dispersion of actinides in the environment and characterization of environmental radioactive particles

Radioactive particles from three locations were investigated for elemental composition, oxidation states of matrix elements, and origin. Instrumental techniques applied to the task were scanning electron microscopy, X-ray and gamma-ray spectrometry, secondary ion mass spectrometry, and synchrotron radiation based microanalytical techniques comprising X-ray fluorescence spectrometry, X-ray fluorescence tomography, and X-ray absorption near-edge structure spectroscopy. Uranium-containing low activity particles collected from Irish Sea sediments were characterized in terms of composition and distribution of matrix elements and the oxidation states of uranium. Indications of the origin were obtained from the intensity ratios and the presence of thorium, uranium, and plutonium. Uranium in the particles was found to exist mostly as U(IV). Studies on plutonium particles from Runit Island (Marshall Islands) soil indicated that the samples were weapon fuel fragments originating from two separate detonations: a safety test and a low-yield test. The plutonium in the particles was found to be of similar age. The distribution and oxidation states of uranium and plutonium in the matrix of weapon fuel particles from Thule (Greenland) sediments were investigated. The variations in intensity ratios observed with different techniques indicated more than one origin. Uranium in particle matrixes was mostly U(IV), but plutonium existed in some particles mainly as Pu(IV), and in others mainly as oxidized Pu(VI). The results demonstrated that the various techniques were effectively applied in the characterization of environmental radioactive particles. An on-line method was developed for separating americium from environmental samples. The procedure utilizes extraction chromatography to separate americium from light lanthanides, and cation exchange to concentrate americium before the final separation in an ion chromatography column. The separated radiochemically pure americium fraction is measured by alpha spectrometry. The method was tested with certified sediment and soil samples and found to be applicable for the analysis of environmental samples containing a wide range of Am-241 activity. Proceeding from the on-line method developed for americium, a method was also developed for separating plutonium and americium. Plutonium is reduced to Pu(III), and separated together with Am(III) throughout the procedure. Pu(III) and Am(III) are eluted from the ion chromatography column as anionic dipicolinate and oxalate complexes, respectively, and measured by alpha spectrometry.

TlBr raw material purification, crystal growth, annealing, detector fabrication and characterisation for gamma-ray detector applications

The research reported in this thesis dealt with single crystals of thallium bromide grown for gamma-ray detector applications. The crystals were used to fabricate room temperature gamma-ray detectors. Routinely produced TlBr detectors often are poor quality. Therefore, this study concentrated on developing the manufacturing processes for TlBr detectors and methods of characterisation that can be used for optimisation of TlBr purity and crystal quality. The processes under concern were TlBr raw material purification, crystal growth, annealing and detector fabrication. The study focused on single crystals of TlBr grown from material purified by a hydrothermal recrystallisation method. In addition, hydrothermal conditions for synthesis, recrystallisation, crystal growth and annealing of TlBr crystals were examined. The final manufacturing process presented in this thesis deals with TlBr material purified by the Bridgman method. Then, material is hydrothermally recrystallised in pure water. A travelling molten zone (TMZ) method is used for additional purification of the recrystallised product and then for the final crystal growth. Subsequent processing is similar to that described in the literature. In this thesis, literature on improving quality of TlBr material/crystal and detector performance is reviewed. Aging aspects as well as the influence of different factors (temperature, time, electrode material and so on) on detector stability are considered and examined. The results of the process development are summarised and discussed. This thesis shows the considerable improvement in the charge carrier properties of a detector due to additional purification by hydrothermal recrystallisation. As an example, a thick (4 mm) TlBr detector produced by the process was fabricated and found to operate successfully in gamma-ray detection, confirming the validity of the proposed purification and technological steps. However, for the complete improvement of detector performance, further developments in crystal growth are required. The detector manufacturing process was optimized by characterisation of material and crystals using methods such as X-ray diffraction (XRD), polarisation microscopy, high-resolution inductively coupled plasma mass (HR-ICPM), Fourier transform infrared (FTIR), ultraviolet and visual (UV-Vis) spectroscopy, field emission scanning electron microscope (FESEM) and energy-dispersive X-ray spectroscopy (EDS), current-voltage (I-V) and capacity voltage (CV) characterisation, and photoconductivity, as well direct detector examination.

CADASIL: molecular studies on the most common hereditary vascular dementing disorder

Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) is the most common hereditary vascular dementia. CADASIL is a systemic disease of small and medium-sized arteries although the symptoms are almost exclusively neurological, including migraineous headache, recurrent ischemic episodes, cognitive impairment and, finally, subcortical dementia. CADASIL is caused by over 170 different mutations in the NOTCH3 gene, which encodes a receptor expressed in adults predominantly in the vascular smooth muscle cells. The function of NOTCH3 is not crucial for embryonic development but is needed after birth. NOTCH3 directs postnatal arterial maturation and helps to maintain arterial integrity. It is involved in regulation of vascular tone and in the wound healing of a vascular injury. In addition, NOTCH3 promotes cell survival by inducing expression of anti-apoptotic proteins. NOTCH3 is a membrane-spanning protein with a large extracellular domain (N3ECD) containing 34 epidermal growth factor-like (EGF) repeats and a smaller intracellular domain with six ankyrin repeats. All CADASIL mutations are located in the EGF repeats and the majority of the mutations cause gain or loss of one cysteine residue in one of these repeats leading to an odd number of cysteine residues, which in turn leads to misfolding of N3ECD. This misfolding most likely alters the maturation, targetting, degradation and/or function of the NOTCH3 receptor. CADASIL mutations do not seem to affect the canonical NOTCH3 signalling pathway. The main pathological findings are the accumulation of the NOTCH3 extracellular domain on degenerating vascular smooth muscle cells (VSMCs), accumulation of granular osmiophilic material (GOM) in the close vicinity of VSMCs as well as fibrosis and thickening of arterial walls. Narrowing of the arterial lumen and local thrombosis cause insufficient blood flow, mainly in small arteries of the cerebral white matter, resulting in tissue damage and lacunar infarcts. CADASIL is suspected in patients with a suggestive family history and clinical picture as well as characteristic white matter alterations in magnetic resonance imaging. A definitive verification of the diagnosis can be achieved by identifying a pathogenic mutation in the NOTCH3 gene or through the detection of GOM by electron microscopy. To understand the pathology underlying CADASIL, we have generated a unique set of cultured vascular smooth muscle cell (VSMC) lines from umbilical cord, placental, systemic and cerebral arteries of CADASIL patients and controls. Analyses of these VSMCs suggest that mutated NOTCH3 is misfolded, thus causing endoplasmic reticulum stress, activation of the unfolded protein response and increased production of reactive oxygen species. In addition, mutation in NOTCH3 causes alterations in actin cytoskeletal structures and protein expression, increased branching and abnormal node formation. These changes correlate with NOTCH3 expression levels within different VSMCs lines, suggesting that the phenotypic differences of SMCs may affect the vulnerability of the VSMCs and, therefore, the pathogenic impact of mutated NOTCH3 appears to vary in the arteries of different locations. Furthermore, we identified PDGFR- as an immediate downstream target gene of NOTCH3 signalling. Activation of NOTCH induces up-regulation of the PDGFR- expression in control VSMCs, whereas this up-regulation is impaired in CADASIL VSMCs and might thus serve as an alternative molecular mechanism that contributes to CADASIL pathology. In addition, we have established the congruence between NOTCH3 mutations and electron microscopic detection of GOM with a view to constructing a strategy for CADASIL diagnostics. In cases where the genetic analysis is not available or the mutation is difficult to identify, a skin biopsy is an easy-to-perform and highly reliable diagnostic method. Importantly, it is invaluable in setting guidelines concerning how far one should proceed with the genetic analyses.

Revision of the family Alycidae (Acariformes, Acari), with special reference to European species

The thesis provides a proposal to divide Alycidae G. Canestrini & Fanzago into two subfamilies and four tribes. This new hierarchy is based on a reassessment and reranking of new and previously known synapomorphies of the clusters concerned by cladistic analysis, using 60 morphological characters for 48 ingroup species. The basic characters of the taxa are illustrated either by SEM micrographs (Scanning Electron Microscopy) or by outline drawings. The presented classification includes the definitions of Alycini G. Canestrini & Fanzago new rank; Bimichaeliini Womersley new rank; Petralycini new rank; and the (re)descriptions of Alycus C.L. Koch, Pachygnathus Dugès, Amphialycus Zachvatkin, Bimichaelia Thor and Laminamichaelia gen. nov. The species described or redescribed are: Pachygnathus wasastjernae sp. nov. from Kvarken (Merenkurkku), Finland; Pachygnathus villosus Dugès (in Oken); Alycus roseus C.L. Koch; Alycus denasutus (Grandjean) comb. and stat. nov.; Alycus trichotus (Grandjean) comb. nov.; Alycus marinus (Schuster) comb. nov.; Amphialycus (Amphialycus) pentophthalmus Zachvatkin; Amphialycus (Amphialycus) leucogaster (Grandjean); and Amphialycus (Orthacarus) oblongus (Halbert) comb. nov.; Bimichaelia augustana (Berlese); Bimichaelia sarekensis Trägårdh; Laminamichaelia setigera (Berlese) comb. nov.; Laminamichelia arbusculosa (Grandjean) comb. nov.; Laminamichelia subnuda (Berlese) comb. nov. and Petralycus unicornis Grandjean. Fourteen nominal species were found to be junior synonymies. The importance of sensory organs in taxonomy is well recognized, but inclusion of the elaborate skin pattern seemed to improve essentially the usefulness of the prodorsal sensory area. The detailed pictures of the prodorsa of the European alycids could be used like passport photographs for the species. A database like this of prodorsa of other mite taxa as well might be an answer to future needs of species identification in soil zoology, ecology and conservation.

The significance of brittle reaction layers in fusing of dental ceramics to titanium

This thesis comprises four intercomplementary parts that introduce new approaches to brittle reaction layers and mechanical compatibility of metalloceramic joints created when fusing dental ceramics to titanium. Several different methods including atomic layer deposition (ALD), sessile drop contact angle measurements, scanning acoustic microscopy (SAM), three-point bending (TPB, DIN 13 927 / ISO 9693), cross-section microscopy, scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS) were employed. The first part investigates the effects of TiO2 layer structure and thickness on the joint strength of the titanium-metalloceramic system. Samples with all tested TiO2 thicknesses displayed good ceramics adhesion to Ti, and uniform TPB results. The fracture mode was independent of oxide layer thickness and structure. Cracking occurred deeper inside titanium, in the oxygen-rich Ti[O]x solid solution surface layer. During dental ceramics firing TiO2 layers dissociate and joints become brittle with increased dissolution of oxygen into metallic Ti and consequent reduction in the metal plasticity. To accomplish an ideal metalloceramic joint this needs to be resolved. The second part introduces photoinduced superhydrophilicity of TiO2. Test samples with ALD deposited anatase TiO2 films were produced. Samples were irradiated with UV light to induce superhydrophilicity of the surfaces through a cascade leading to increased amount of surface hydroxyl groups. Superhydrophilicity (contact angle ~0˚) was achieved within 2 minutes of UV radiation. Partial recovery of the contact angle was observed during the first 10 minutes after UV exposure. Total recovery was not observed within 24h storage. Photoinduced ultrahydrophilicity can be used to enhance wettability of titanium surfaces, an important factor in dental ceramics veneering processes. The third part addresses interlayers designed to restrain oxygen dissolution into Ti during dental ceramics fusing. The main requirements for an ideal interlayer material are proposed. Based on these criteria and systematic exclusion of possible interlayer materials silver (Ag) interlayers were chosen. TPB results were significantly better in when 5 μm Ag interlayers were used compared to only Al2O3-blasted samples. In samples with these Ag interlayers multiple cracks occurred inside dental ceramics, none inside Ti structure. Ag interlayers of 5 μm on Al2O3-blasted samples can be efficiently used to retard formation of the brittle oxygen-rich Ti[O]x layer, thus enhancing metalloceramic joint integrity. The most brittle component in metalloceramic joints with 5 μm Ag interlayers was bulk dental ceramics instead of Ti[O]x. The fourth part investigates the importance of mechanical interlocking. According to the results, the significance of mechanical interlocking achieved by conventional surface treatments can be questioned as long as the formation of the brittle layers (mainly oxygen-rich Ti[O]x) cannot be sufficiently controlled. In summary in contrast to former impressions of thick titanium oxide layers this thesis clearly demonstrates diffusion of oxygen from sintering atmosphere and SiO2 to Ti structures during dental ceramics firing and the following formation of brittle Ti[O]x solid solution as the most important factors predisposing joints between Ti and SiO2-based dental ceramics to low strength. This among other predisposing factors such as residual stresses created by the coefficient of thermal expansion mismatch between dental ceramics and Ti frameworks can be avoided with Ag interlayers.

Effect of water vapour stabilization of raw materials on the quality of the inhalation product

Generation of raw materials for dry powder inhalers by different size reduction methods can be expected to influence physical and chemical properties of the powders. This can cause differences in particle size, size distribution, shape, crystalline properties, surface texture and energy. These physical properties of powders influence the behaviour of particles before and after inhalation. Materials with an amorphous surface have different surface energy compared to materials with crystalline surface. This can affect the adhesion and cohesion of particles. Changes in the surface nature of the drug particles results in a change in product performance. By stabilization of the raw materials the amorphous surfaces are converted into crystalline surfaces. The primary aim of the study was to investigate the influence of the surface properties of the inhalation particles on the quality of the product. The quality of the inhalation product is evaluated by measuring the fine particle dose (FPD). FDP is the total dose of particles with aerodynamic diameters smaller than 5,0 μm. The secondary aim of this study was to achieve the target level of the FPD and the stability of the FPD. This study was also used to evaluate the importance of the stabilization of the inhalation powders. The study included manufacturing and analysing drug substance 200 μg/dose inhalation powder batches using non-stabilized or stabilized raw materials. The inhaler formulation consisted of micronized drug substance, lactose <100μm and micronized lactose <10μm. The inhaler device was Easyhaler®. Stabilization of the raw materials was done in different relative humidity, temperature and time. Surface properties of the raw materials were studied by dynamic vapour sorption, scanning electron microscopy and three-point nitrogen adsorption technique. Particle size was studied by laser diffraction particle size analyzer. Aerodynamic particle size distribution from inhalers was measured by new generation impactor. Stabilization of all three raw materials was successful. A clear difference between nonstabilized and stabilized raw materials was achieved for drug substance and lactose <10μm. However for lactose <100μm the difference wasn’t as clear as wanted. The surface of the non-stabilized drug substance was more irregular and the particles had more roughness on the surface compared to the stabilized drug substances particles surface. The surface of the stabilized drug particles was more regular and smoother than non-stabilized. Even though a good difference between stabilized and non-stabilized raw materials was achieved, a clear evidence of the effect of the surface properties of the inhalation particles on the quality of the product was not observed. Stabilization of the raw materials didn’t lead to a higher FPD. Possible explanations for the unexpected result might be too rough conditions in the stabilization of the drug substance or smaller than wanted difference in the degree of stabilization of the main component of the product <100μm. Despite positive effects on the quality of the product were not seen there appears to be some evidence that stabilized drug substance results in smaller particle size of dry powder inhalers.

Konjac- ja galaktoglukomannaanipohjaiset emulsiokalvot

Emulsiokalvolla tarkoitetaan kalvoa, joka on valmistettu haihduttamalla ylimääräinen vesi pois emulsiosta. Polysakkaridipohjainen emulsiokalvo koostuu kalvonmuodostuspolysakkaridista, rasvasta, emulgointiaineesta ja pehmittimestä. Kirjallisuusosassa selvitettiin, mitä raaka-aineita polysakkaridipohjaisissa emulsiokalvoissa käytetään ja mitkä tekijät vaikuttavat emulsiokalvojen vesihöyrynläpäisevyyteen ja mekaanisiin ominaisuuksiin. Tutkimuksen kokeellisen osan tavoitteena oli selvittää, miten konjac-glukomannaani (KGM) ja kuusen galaktoglukomannaani (GGM) soveltuvat emulsiokalvon raaka-aineiksi. Lisäksi selvitettiin, miten rasvan tyyppi ja rasvapitoisuus vaikuttavat GGM-KGM-pohjaisten emulsiokalvojen mekaanisiin ominaisuuksiin ja vesihöyrynläpäisevyyteen. Mehiläisvahasta, mäntyöljystä ja rypsiöljystä valmistettiin emulsiokalvot, joissa oli 30 %:n (paino-% GGM:sta) rasvapitoisuudet. Lisäksi mehiläisvahasta valmistettiin emulsiokalvot, joissa oli 10 ja 50 % mehiläisvahaa. Emulsiokalvoja verrattiin vertailukalvoon, jossa ei ollut rasvaa. Kalvoissa käytetty KGM:n ja GGM:n suhde oli 1:1. Kalvoista mitattiin vesihöyrynläpäisevyys ja -läpäisynopeus, vetolujuus, Youngin moduuli ja murtovenymä. Näiden lisäksi kalvojen poikkileikkaus kuvattiin pyyhkäisyelektronimikroskoopilla. GGM ja KGM soveltuvat emulsiokalvon raaka-aineiksi. Huoneenlämpötilassa kuivatuista kalvoista saatiin tasaisemman näköisiä kuin lämpökaapissa kuivatuista. Pyyhkäisyelektronimikroskooppikuvissa vahapisarat olivat öljypisaroita pienempiä, mikä mahdollisesti vaikutti siihen, että vahapisarat pysyivät paremmin kiinnittyneenä kalvomatriisissa. Öljypisaroiden koko oli kalvoissa noin 10 ?m ja vahapisaroiden 2–6 ?m. Vesihöyrynläpäisynopeus oli pienin 50 %:n mehiläisvahakalvolla (p < 0,05). Vesihöyrynläpäisevyys laski lineaarisesti mehiläisvahapitoisuuden suurentuessa. Öljykalvot ja 10 %:n mehiläisvahakalvo eivät eronneet tilastollisesti merkitsevästi vesihöyrynläpäisevyyden suhteen vertailukalvosta. Pienin vetolujuus ja Youngin moduuli oli 50 %:n mehiläisvahakalvolla. Vertailukalvo oli kestävin ja jäykin. Murtovenymän suhteen kalvot eivät eronneet toisistaan tilastollisesti merkitsevästi. Tutkimuksessa onnistuttiin valmistamaan GGM-KGM-pohjaisia emulsiokalvoja, jotka pidättivät vesihöyryä vertailukalvoa paremmin ja silti säilyttivät mekaaniset ominaisuutensa kohtuullisen hyvin.

Characterization and evaluation of melibiose as novel excipient in tablet compaction

Lactose is probably the most used tablet excipient in the field of pharmacy. Although lactose is thoroughly characterized and available in many different forms there is a need to find a replacer for lactose as a filler/binder in tablet formulations because it has some downsides. Melibiose is a relatively unknown disaccharide that has not been thoroughly characterized and not previously used as an excipient in tablets. Structurally melibiose is close to lactose as it is also formed from the same two monosaccharides, glucose and galactose. Aim of this research is to characterize and to study physicochemical properties of melibiose. Also the potential of melibiose to be used as pharmaceutical tablet excipient, even as a substitute for lactose is evaluated. Current knowledge about fundamentals of tableting and methods for determinating of deformation behavior and tabletability are reviewed. In this research Raman spectroscopy, X-ray powder diffraction (XRPD), near-infrared spectroscopy (NIR) and Fourier-transform infrared spectroscopy (FT-IR) were used to study differences between two melibiose batches purchased from two suppliers. In NIR and FT-IR measurements no difference between materials could be observed. XPRD and Raman however found differences between the two melibiose batches. Also the effects of moisture content and heating to material properties were studied and moisture content of materials seems to cause some differences. Thermal analytical methods, differential scanning calorimetry (DSC) and thermogravimetry (TG) were used to study thermal behaviour of melibiose and difference between materials was found. Other melibiose batch contains residual water which evaporates at higher temperatures causing the differences in thermal behaviour. Scanning electron microscopy images were used to evaluate particle size, particle shape and morphology. Bulk, tapped and true densities and flow properties of melibiose was measured. Particle size of the melibiose batches are quite different resulting causing differences in the flowability. Instrumented tableting machine and compression simulator were used to evaluate tableting properties of melbiose compared to α-lactose monohydrate. Heckel analysis and strain-rate sensitivity index were used to determine deformation mechanism of melibiose monohydrate in relation to α–lactose monohydrate during compaction. Melibiose seems to have similar deformation behaviour than α-lactose monohydrate. Melibiose is most likely fragmenting material. Melibiose has better compactibility than α – lactose monohydrate as it produces tablets with higher tensile strength with similar compression pressures. More compression studies are however needed to confirm these results because limitations of this study.