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1.
Int J Anal Chem ; 2018: 7170539, 2018.
Article in English | MEDLINE | ID: mdl-30174695

ABSTRACT

This manuscript describes comprehensive approach for assessment of degradation behavior of simvastatin employing experimental design methodology as scientific multifactorial strategy. Experimental design methodology was used for sample preparation and UHPLC method development and optimization. Simvastatin was subjected to stress conditions of oxidative, acid, base, hydrolytic, thermal, and photolytic degradation. Using 2n full factorial design degradation conditions were optimized to obtain targeted level of degradation. Screening for optimal chromatographic condition was made by Plackett-Burman design and optimization chromatographic experiments were conducted according to Box-Behnken design. Successful separation of simvastatin from the impurities and degradation products was achieved on Poroshell 120 EC C18 50 × 3.0 mm 2.7 µm, using solutions of 20 mM ammonium formate pH 4.0 and acetonitrile as the mobile phase in gradient mode. The proposed method was validated according to International Conference on Harmonization (ICH) guidelines. Validation results have shown that the proposed method is selective, linear, sensitive, accurate, and robust and it is suitable for quantitative determination of simvastatin and its impurities. Afterwards, the degradation products were confirmed by a direct hyphenation of liquid chromatograph to ion-trap mass spectrometer with heated electrospray ionization interface. This study highlights the multiple benefits of implementing experimental design, which provides a better understanding of significant factors responsible for degradation and ensures successful way to achieve degradation and can replace the trial and error approach used in conventional forced degradation studies.

2.
Nat Prod Commun ; 12(1): 35-42, 2017 Jan.
Article in English | MEDLINE | ID: mdl-30549820

ABSTRACT

Qualitative and quantitative analyses of polyphenols extracted from 21 Malus domestica cultivars using ultra high performance liquid chromatography with diode array detection coupled to heated electrospray ionization mass spectrometric detection was performed for separation of 27 phenolic compounds on a reversed phase UHPLC column with an optimized gradient consisting of 1% formic acid in water and 1% formic acid in methanol within 20 minutes. According to retention times, UV maxima and mass spectra of the peaks in the chromatograms obtained from extracts of apple peel, flesh and leaves, the polypfienolic compounds were identified and quantified. Based on fragmentation patterns, 6 phenolic acids, 5 flavan-3-ols, 5 dihydrochalcones, 8 flavonols and 3 flavone derivatives were characterized in the studied samples. The method was then employed for analysis of the polyphenolic pattern of 21 apple cultivars, both commercial and autochthonous for the Macedonian region, as well as for monitoring the influence of long term storage on the polyphenolic content and composition of apple fruits and for comparison of polyphenolic profiles of apple cultivars during two years of harvesting. The obtained results revealed minor differences in the quality and major variation in the content of phenolic compounds in the flesh, peel and leaves in the studied apple cultivars that is attributed mainly to cultivar differences and meteorological factors.


Subject(s)
Fruit/chemistry , Malus/chemistry , Plant Leaves/chemistry , Polyphenols/chemistry , Chromatography, High Pressure Liquid , Food Storage , Mass Spectrometry , Plant Extracts/chemistry , Spectrometry, Mass, Electrospray Ionization , Spectrophotometry, Ultraviolet
3.
Article in English | MEDLINE | ID: mdl-24802199

ABSTRACT

In the case of a child with a rare disease the role of the special educator and rehabilitator is important if in addition to the primary disease the child is affected by motor, sensory, mental or emotional deficiency. The special educator and rehabilitator participates in the discovery on their first visit to the health institution. For each child the special educator and rehabilitator prepares a file with all the relevant data, takes anamnestic data, or complements it, to get a complete picture of the problem, and inputs data from the observation. S/he collaborates with members of the professional team. S/he provides advice, assists and works with the parents. S/he assesses the psycho-motor abilities of the person and how the person functions in the environment. The special educator and rehabilitator performs the following assessments: assessment of dominant lateralization; assessment of psycho-motor abilities of the upper extremities; assessment of psycho-motor abilities of the lower extremities; differentiation of the motor abilities of the fingers; assessment of the possibilities for maintaining the equilibrium of the body; assessment of coordination of the upper and lower extremities in rhythm. The special educator and rehabilitator assesses and examines the praxical organization, specifically melokinetic, ideomotory, ideatory and constructive praxis. This includes assessment of the graphomotoric as a practical activity through testing for quality of lineation, graphomotoric array through analysis of the maturity of the manuscript and the disgraphy of the manuscript. Gnostic organization is examined through assessment of knowledge of body parts, assessment of knowledge of lateralization on themselves and others, assessment of experience and orientation in space and time. Practognostic organization is examined with tests for imitation of movements. Evaluation of the organization of speech through the test of articulation on voices, semantic test and evaluation of lexical abilities and dyslexic reading. Assessment of the organization of cognitive functions where thought operation is expressed, and the special educator investigates the level of comprehension of: serialization, classification, correspondence and conservation. At the end, the child's behaviour is examined. Based on the data obtained, a plan and a strategy for further treatment is developed. After a certain period of time the child is re-examined (evaluation) and we check whether are there any advances in education and rehabilitation. The special educator and rehabilitator is in constant contact with the parents for certain problems that the children have with social adaptation, and they build strategies for future activities.


Subject(s)
Education, Special/methods , Parents/psychology , Rare Diseases/rehabilitation , Social Adjustment , Child , Humans
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