Sensory assessment and acceptability of coated tablets relationship between instrumental methods and human data

Development of acceptable medicines is central for adherence and effectiveness of treatment. However, the assessment of medicines’ acceptability has not yet been standardised. Correlating in vitro and in vivo acceptability data would facilitate the development of acceptable medicines, but research in this area is limited. This thesis aims to evaluate and correlate in vivo and in vitro acceptability data of conventional tablets with a range of coatings. In two randomised studies participants, ranging from pre-school children to older adults, evaluated acceptability of tablets in two aspects: ease-of-swallowing and palatability. Sensory attributes which were statistically related to acceptability were established with high selectivity and specificity, i.e. bitterness, aftertaste, stickiness, slipperiness, and smoothness. Discrepancies found between children and adults responses indicated differences in their perception of tablets and acceptability. Also developed was an array of instrumental methods and results were investigated for links to sensory perception. A linear relationship between tribology and oral sensory perception, specifically for ease-of-swallowing, slipperiness and stickiness, of tablets was found and is described for the first time. Lastly, a vocabulary describing tablets has been collected and organized into a lexicon, which provides the first step towards the standardisation of sensory testing, as a part of acceptability evaluation

Investigation of Volatile Organic Compounds (VOCs) released as a result of spoilage in whole broccoli, carrots, onions and potatoes with HS-SPME and GC-MS

Vegetable spoilage renders a product undesirable due to changes in sensory characteristics. The aim of this study was to investigate the change in the fingerprint of VOC composition that occur as a result of spoilage in broccoli, carrots, onions and potatoes. SPME and GC-MS techniques were used to identify and determine the relative abundance of VOC associated with both fresh and spoilt vegetables. Although a number of similar compounds were detected in varying quantities in the headspace of fresh and spoilt samples, certain compounds which were detected in the headspace of spoilt vegetables were however absent in fresh samples. Analysis of the headspace of fresh vegetables indicated the presence of a variety of alkanes, alkenes and terpenes. Among VOCs identified in the spoilt samples were dimethyl disulphide and dimethyl sulphide in broccoli; Ethyl propanoate and Butyl acetate in carrots; 1-Propanethioland 2-Hexyl-5-methyl-3(2H)-furanone in onions; and 2, 3-Butanediol in potatoes. The overall results of this study indicate the presence of VOCs that can serve as potential biomarkers for early detection of quality deterioration and in turn enhance operational and quality control decisions in the vegetable industry

DEVELOPMENT OF NEW PRODUCTS FOR HAIR COLORING AND HAIR BLEACHING

Products claiming to be environm\uadentally sustainable, naturally derived and free from \u201cchemicals\u201d, \u201cparaben free\u201d, \u201cvegan\u201d have gained much attention in the consumer market. Herbal dyes are biodegradable, non-toxic, soft and without any side effects. Keeping in mind these factors we did a study on plants that color hair. During our research we found different plants with health benefits derived from various parts of the tree such as flowers, bark, seeds, leaves and roots. The extracts powder have been diluted in water and tested by an acidic pH and a basic pH. Furthermore, some plants were tested in synergy with other plants or with various miscellaneous plants. In the second part of this project we focused on the research of a new raw material that allows a reduction of skin irritation and sensitivity reaction due to synthetic dyes and in color formulation with monoethanolamine. The most common products for hair color formulated with synthetic dyes, allow to obtain good results, but such products can damage the structure of hair. It becomes more porous and in many cases can cause allergic reaction, such as itching, redness, desquamation, etc. PPD (Para-phenylenediamine) is a key ingredient found in the majority of permanent and semi-permanent hair dyes. It is the most common cause of an allergic reaction to hair coloring. Other chemicals in hair dyes, such as ammonia, peroxide, PTDS (para-toluenediamine sulfate), fragrance and pigments can also trigger scalp inflammation and itchiness. During our research we found the innovative formulation of Shield P-17 that allows without affecting the color results a net reduction of sensitization reactions and allergy due to PPD/PTD in the dye event in presence of MEA. It can be added directly into the dye\u2019s preparatory formula after dyes have been added and around 60\ub0C. In this part of the project we formulated four formulas Black, Brown, Red, Blonde following the mechanism of oxidation dyes. The study in vivo and salon test was done to evaluate scalp irritation, skin discomfort and performance during and after the application of a hair color formulated with Shield P-17. In the end we selected four formulas for each color to verify the product stability, meaning how long the product can maintain its original form without any visible changes, its intended physical, chemical and microbiological qualities as well as functionality under appropriate conditions. The third part of the project focused on the hair bleaching products. The most common products for hair bleaching are formulated with ammonium persulphate and potassium persulphate which allow to obtain good results, but such products can damage the structure of hair. It becomes more porous and in many cases can cause irritating, redness, desquamation, allergic reaction etc. Keeping in mind these factors we did a research of new raw materials that have the capacity to improve the bleaching hair process and the sensoriality. Zeosafe CL-07 (INCI Name Zeolite) is a mineral of volcanic origin, with a regular and microporous crystal structure, characterized by a huge amount of void volumes inside the crystals. Chemically, zeolite is a hydrated aluminosilicates with three dimensionally structures with regular channels and interconnected pores of 4\ub0 diameter, contains water and cations (Ca\ub2\u207a, Mg\ub2\u207a, Na\u207a, K\u207a..) inside the structure. It has characteristics as molecular sieve, absorbent and cation exchange capacity with high selectivity. Due to these characteristics it has used to increase the bleaching process. Our study consists of five phases: application of the bleaching powder with a new chelant; the research of new actives to improve the final sensoriality; the application of bleaching powder with the active; the application of bleaching powder containing chelant and active substances; Other test by changing temperature, dilution, time, volume of hydrogen peroxide