52 research outputs found
OslobaÄanje celekoksiba iz mukoadhezivnih diskova s polimerima poliaspartamidnog tipa
A series of mucoadhesive disks with celecoxib as a model drug of very low aqueous solubility were prepared and characterized. Two polymers of polyaspartamide type, poly,-(N-2-hydroxyethyl-DL-aspartamide) (PHEA, 1) and its thiolated analogue poly[Ī±,Ī²-(N-2-hydroxyethyl-DL-aspartamide)]-poly[Ī±,Ī²-(N-2-thioethyl-DL-aspartamide)] copolymer (PHTA, 2a,b), and two commercially available polymers Carbopol 934P and hydroxypropylmethyl cellulose 4000 were used as excipients. Disks containing a mixture of equivalent amounts of thiomer 2b and Carbopol 934P as an excipient exhibited the highest dissolution rate.Pripravljeni su i karakterizirani mukoadhezivni diskovi s celekoksibom kao lipofilnom modelnom supstancijom. Kao ekscipiensi uporabljena su dva polimera poliaspartamidnog tipa, poli[Ī±,Ī²-(N-2-hidroksietil-DL-aspartamid) (PHEA, 1) i njegov tiolirani analog poli[Ī±,Ī²-(N-2-hidroksietil-DL-aspartamid)]-poli[Ī±,Ī²-(N-2-tioetil-DL-aspartamid)] kopolimer (PHTA, 2a,b), te dva komercijalno dostupna polimera Carbopol 934P i hidroksipropilmetilceluloza 4000. Najbolji profil oslobaÄanja celekoksiba postignut je iz diskova sastavljenih od tiomera 2b i Carbopola 934P u masenom omjeru 1:1
FILLAGRIN ā MULTIFUNCTIONAL PROTEIN
UÄinkovita fi zikalna, kemijska, biokemijska i imunosna funkcija kože podrazumijeva odgovarajuÄu strukturu epidermisa. Filagrin, jedan od epidermalnih proteina, kljuÄan je za stvaranje korneocita i intracelularnih metabolita koji doprinose održavanju vlažnosti sloja stratum korneum i kiselog pH povrÅ”ine kože. Opisane su meÄutim, brojne mutacije gena koji kodira (pro)fi lagrin, upalna stanja i razni vanjski Äimbenici koji rezultiraju deficitom fi lagrina. Defi cit fi lagrina dokazan je u raznim kožnim bolestima, a spoznaje o njegovom metaboliÄkom procesiranju otkrivaju i ciljeve za novu terapijsku strategiju u takvim bolestima. U ovom pregledu opisane su glavne znaÄajke stvaranja i metabolizma fi lagrina, te kliniÄke implikacije
defi cita fi lagrina u etiopatogenezi nekih kožnih bolesti.Effective physical, chemical, biochemical and immune function of the skin requires a corresponding structure of the epidermis. Filaggrin, one of epidermal proteins, is essential for the formation of corneocytes and intracellular metabolites, which in turn contribute to maintaining the stratum corneum humidity and acidic pH of the skin surface. However, a number of profi laggrin gene mutations have been described, as well as different infl ammatory conditions and different external factors that all resulted in fi laggrin defi ciency. Filaggrin defi ciency is recorded in different skin diseases and discoveries related to metabolic processing of fi laggrin point to new goals in therapeutic strategies. In this preview, the main properties
of the formation and metabolism of fi laggrin are described, as well as clinical implications of fi laggrin defi ciency in the etiopathogenesis of some skin diseases
Prikaz sluÄaja stanja po avaskularnoj nekrozi glave I. metatarzalne kosti kod vrhunskog mladog sportaÅ”a
PredviÄanje heterozisa na osnovu fenotipske distance roditeljskih linija kukuruza Å”eÄerca
A relatively narrow genetic background, limited sources of germplasm that satisfies commercial standards, poorly defined heterotic groups, as well as a small span for yield and quality estimation are reasons for the modest improvement in sweet corn yields in comparison with standard grain quality maize. Therefore, any additional information could be of a great use. Based on the phenotypic characterization according to UPOV descriptor, phenotypic distances of 14 ZP sweet corn inbred lines were evaluated, and clustering was performed. Grouping showed that 9 out of 11 hybrids obtained by crossings of 14 sweet corn inbred lines had parental lines assigned to different subclusters. Two hybrids whose parental components belonged to the same subcluster had some important specific traits, such as early maturity (ZP 111su), and super-sweet germplasm (ZP 407su). Results obtained by this procedure could be of great assistance in the process of selecting parental lines for the future crossings.Relativno uska genetiÄka osnova, ograniÄeni resursi germplazme koja zadovoljava komercijalne standarde, loÅ”e definisane heterotiÄne grupe kao i kratko vreme koje je na raspolaganju za procenu prinosa i kvaliteta su razlozi slabijeg unapreÄenja prinosa hibrida kukuruza Å”eÄerca u poreÄenju sa hibridima standardnog kvaliteta zrna. Stoga svaka dodatna informacija može da bude od velikog znaÄaja. Na osnovu karakterizacije po UPOV deskriptoru uraÄena je klaster analiza 14 ZP linija kukuruza Å”eÄerca. Grupisanje je ukazalo da su se roditeljske linije 9 od 11 hibrida grupisale u razliÄite podklastere. Dva hibrida, Äije su se roditeljske linije grupisale u isti klaster su nosioci nekih specifiÄnih karakteristika kao Å”to je ranostasnost (ZP 111su) i super-slatka germplazma (ZP 407su). Rezultati grupisanja dobijeni ovom procedurom mogu biti od velike pomoÄi pri izboru roditeljskih linija za buduÄa ukrÅ”tanja linija Å”eÄerca
Karakterizacija Ī²-glukana izoliranih iz pivskoga kvasca te osuÅ”enih razliÄitim metodama
Two different procedures have been used for isolation of water-insoluble Ć-glucans from brewerās yeast: alkaline-acidic isolation (AA) and alkaline-acidic isolation with mannoprotein removal (AAM). The obtained Ć-glucans were then dried by air-drying, lyophilization and combination of sonication and spray-drying. Ć-Glucan preparations obtained by AA and AAM isolations had similar values of dry mass, total polysaccharides, proteins and organic elemental microanalysis. The mass fractions of Ć-glucan in total polysaccharides were significantly affected by different isolation procedures. Fourier transform infrared (FTIR) spectra of all preparations had the appearance typical for (1ā3)-Ć-D-glucan. Lyophilization and especially air-drying caused a higher degree of agglomeration and changes in Ć-glucan microstructure. Sonication followed by spray-drying resulted in minimal structural changes and negligible formation of agglomerates.Netopljivi Ī²-glukani izolirani su iz pivskoga kvasca primjenom dvaju razliÄitih postupaka: alkalno-kiselinskog (AK) i alkalno-kiselinskog s uklanjanjem manoproteina (AKM). Dobiveni pripravci Ī²-glukana osuÅ”eni su na zraku, liofilizacijom i rasprÅ”ivanjem uz prethodnu obradu ultrazvukom. Takvi su pripravci, dobiveni AK i AKM postupcima, imali približno iste vrijednosti suhe tvari, ukupnih polisaharida i proteina, te udjele ugljika, duÅ”ika i kisika odreÄene organskom mikroanalizom. Na udio Ī²-glukana u ukupnim polisaharidima bitno su utjecali razliÄiti postupci izolacije. FT-IR spektri svih pripravaka imali su izgled tipiÄan za (1ā3)-Ī²-D-glukan. SuÅ”enjem na zraku i liofilizacijom doÅ”lo je do znaÄajnih promjena strukture Äestica i aglomeracije Ć-glukana. SuÅ”enje rasprÅ”ivanjem uz prethodnu obradu ultrazvukom nije dovelo do stvaranja nakupina Äestica kao ni do znatnih promjena njihove strukture
Application of Different Drying Methods on Ī²-Glucan Isolated from Spent Brewerās Yeast Using Alkaline Procedure
Water-insoluble (particulate) Ī²-glucan was isolated from the cell walls of spent brewerās yeast using a single-step alkaline treatment. To stabilize Ī²-glucan water suspensions, sonication was successfully applied. Three different drying methods were used: air-drying, lyophilization and spray-drying. Air-drying and lyophilization caused Ī²-glucan particles agglomeration and changes of their microstructure. Sonication combined with spray-drying resulted in minimal Ī²-glucan structural changes and negligible formation of agglomerates. Reaggregation of spray-dried Ī²-glucan particles was minimal even after resuspending in water
Application of Different Drying Methods on Ī²-Glucan Isolated from Spent Brewerās Yeast Using Alkaline Procedure
Water-insoluble (particulate) Ī²-glucan was isolated from the cell walls of spent brewerās yeast using a single-step alkaline treatment. To stabilize Ī²-glucan water suspensions, sonication was successfully applied. Three different drying methods were used: air-drying, lyophilization and spray-drying. Air-drying and lyophilization caused Ī²-glucan particles agglomeration and changes of their microstructure. Sonication combined with spray-drying resulted in minimal Ī²-glucan structural changes and negligible formation of agglomerates. Reaggregation of spray-dried Ī²-glucan particles was minimal even after resuspending in water
Karakterizacija Ī²-glukana izoliranih iz pivskoga kvasca te osuÅ”enih razliÄitim metodama
Two different procedures have been used for isolation of water-insoluble Ć-glucans from brewerās yeast: alkaline-acidic isolation (AA) and alkaline-acidic isolation with mannoprotein removal (AAM). The obtained Ć-glucans were then dried by air-drying, lyophilization and combination of sonication and spray-drying. Ć-Glucan preparations obtained by AA and AAM isolations had similar values of dry mass, total polysaccharides, proteins and organic elemental microanalysis. The mass fractions of Ć-glucan in total polysaccharides were significantly affected by different isolation procedures. Fourier transform infrared (FTIR) spectra of all preparations had the appearance typical for (1ā3)-Ć-D-glucan. Lyophilization and especially air-drying caused a higher degree of agglomeration and changes in Ć-glucan microstructure. Sonication followed by spray-drying resulted in minimal structural changes and negligible formation of agglomerates.Netopljivi Ī²-glukani izolirani su iz pivskoga kvasca primjenom dvaju razliÄitih postupaka: alkalno-kiselinskog (AK) i alkalno-kiselinskog s uklanjanjem manoproteina (AKM). Dobiveni pripravci Ī²-glukana osuÅ”eni su na zraku, liofilizacijom i rasprÅ”ivanjem uz prethodnu obradu ultrazvukom. Takvi su pripravci, dobiveni AK i AKM postupcima, imali približno iste vrijednosti suhe tvari, ukupnih polisaharida i proteina, te udjele ugljika, duÅ”ika i kisika odreÄene organskom mikroanalizom. Na udio Ī²-glukana u ukupnim polisaharidima bitno su utjecali razliÄiti postupci izolacije. FT-IR spektri svih pripravaka imali su izgled tipiÄan za (1ā3)-Ī²-D-glukan. SuÅ”enjem na zraku i liofilizacijom doÅ”lo je do znaÄajnih promjena strukture Äestica i aglomeracije Ć-glukana. SuÅ”enje rasprÅ”ivanjem uz prethodnu obradu ultrazvukom nije dovelo do stvaranja nakupina Äestica kao ni do znatnih promjena njihove strukture
In vitro dissolution/release methods for mucosal delivery systems
In vitro dissolution/release tests are an indispensable tool in the drug product development, its quality control and the regulatory approval process. Mucosal drug delivery systems are designed to provide both local and systemic drug action following ocular, nasal, oromucosal, vaginal or rectal administration. They exhibit significant differences in formulation design, physicochemical characteristics and drug release properties. Therefore it is not possible to devise a single method which would be suitable for release testing of such versatile and complex dosage forms. Different apparatuses and techniques for in vitro release testing for mucosal delivery systems considering the specific conditions at the administration site are described. In general, compendial apparatuses and methods should be used as a first approach in method development when applicable. However, to assure adequate simulation of conditions in vivo, novel biorelevant in vitro dissolution/release methods should be developed. Equipment set up, the selection of dissolution media and volume, membrane type, agitation speed, temperature, and assay analysis technique need to be carefully defined based on mucosal drug delivery system characteristics. All those parameters depend on the delivery system and physiological conditions at the site of application and may vary in a wide range, which will be discussed in details
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