Oslobađanje 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[α,β-(N-2-hydroxyethyl-DL-aspartamide)]-poly[α,β-(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[α,β-(N-2-hidroksietil-DL-aspartamid) (PHEA, 1) i njegov tiolirani analog poli[α,β-(N-2-hidroksietil-DL-aspartamid)]-poli[α,β-(N-2-tioetil-DL-aspartamid)] kopolimer (PHTA, 2a,b), te dva komercijalno dostupna polimera Carbopol 934P i hidroksipropilmetilceluloza 4000. Najbolji profil oslobađanja celekoksiba postignut je iz diskova sastavljenih od tiomera 2b i Carbopola 934P u masenom omjeru 1:1

FILLAGRIN – MULTIFUNCTIONAL PROTEIN

Učinkovita fi zikalna, kemijska, biokemijska i imunosna funkcija kože podrazumijeva odgovarajuću strukturu epidermisa. Filagrin, jedan od epidermalnih proteina, ključan je za stvaranje korneocita i intracelularnih metabolita koji doprinose održavanju vlažnosti sloja stratum korneum i kiselog pH površine kože. Opisane su međutim, brojne mutacije gena koji kodira (pro)fi lagrin, upalna stanja i razni vanjski čimbenici koji rezultiraju deficitom fi lagrina. Defi cit fi lagrina dokazan je u raznim kožnim bolestima, a spoznaje o njegovom metaboličkom procesiranju otkrivaju i ciljeve za novu terapijsku strategiju u takvim bolestima. U ovom pregledu opisane su glavne značajke stvaranja i metabolizma fi lagrina, te kliničke 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

Predviđanje heterozisa na osnovu fenotipske distance roditeljskih linija kukuruza šećerca

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 genetička osnova, ograničeni resursi germplazme koja zadovoljava komercijalne standarde, loše definisane heterotične grupe kao i kratko vreme koje je na raspolaganju za procenu prinosa i kvaliteta su razlozi slabijeg unapređenja prinosa hibrida kukuruza šećerca u poređenju sa hibridima standardnog kvaliteta zrna. Stoga svaka dodatna informacija može da bude od velikog značaja. Na osnovu karakterizacije po UPOV deskriptoru urađena je klaster analiza 14 ZP linija kukuruza šećerca. Grupisanje je ukazalo da su se roditeljske linije 9 od 11 hibrida grupisale u različite podklastere. Dva hibrida, čije su se roditeljske linije grupisale u isti klaster su nosioci nekih specifičnih karakteristika kao što je ranostasnost (ZP 111su) i super-slatka germplazma (ZP 407su). Rezultati grupisanja dobijeni ovom procedurom mogu biti od velike pomoći pri izboru roditeljskih linija za buduća ukrštanja linija šećerca

Karakterizacija β-glukana izoliranih iz pivskoga kvasca te osušenih različitim metodama

Two different procedures have been used for isolation of water-insoluble ß-glucans from brewer’s yeast: alkaline-acidic isolation (AA) and alkaline-acidic isolation with mannoprotein removal (AAM). The obtained ß-glucans were then dried by air-drying, lyophilization and combination of sonication and spray-drying. ß-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 ß-glucan in total polysaccharides were significantly affected by different isolation procedures. Fourier transform infrared (FTIR) spectra of all preparations had the appearance typical for (1→3)-ß-D-glucan. Lyophilization and especially air-drying caused a higher degree of agglomeration and changes in ß-glucan microstructure. Sonication followed by spray-drying resulted in minimal structural changes and negligible formation of agglomerates.Netopljivi β-glukani izolirani su iz pivskoga kvasca primjenom dvaju različitih postupaka: alkalno-kiselinskog (AK) i alkalno-kiselinskog s uklanjanjem manoproteina (AKM). Dobiveni pripravci β-glukana osušeni su na zraku, liofilizacijom i raspršivanjem 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, dušika i kisika određene organskom mikroanalizom. Na udio β-glukana u ukupnim polisaharidima bitno su utjecali različiti postupci izolacije. FT-IR spektri svih pripravaka imali su izgled tipičan za (1→3)-β-D-glukan. Sušenjem na zraku i liofilizacijom došlo je do značajnih promjena strukture čestica i aglomeracije ß-glukana. Sušenje raspršivanjem uz prethodnu obradu ultrazvukom nije dovelo do stvaranja nakupina čestica kao ni do znatnih promjena njihove strukture

Application of Different Drying Methods on β-Glucan Isolated from Spent Brewer’s Yeast Using Alkaline Procedure

Water-insoluble (particulate) β-glucan was isolated from the cell walls of spent brewer’s yeast using a single-step alkaline treatment. To stabilize β-glucan water suspensions, sonication was successfully applied. Three different drying methods were used: air-drying, lyophilization and spray-drying. Air-drying and lyophilization caused β-glucan particles agglomeration and changes of their microstructure. Sonication combined with spray-drying resulted in minimal β-glucan structural changes and negligible formation of agglomerates. Reaggregation of spray-dried β-glucan particles was minimal even after resuspending in water

Application of Different Drying Methods on β-Glucan Isolated from Spent Brewer’s Yeast Using Alkaline Procedure

Water-insoluble (particulate) β-glucan was isolated from the cell walls of spent brewer’s yeast using a single-step alkaline treatment. To stabilize β-glucan water suspensions, sonication was successfully applied. Three different drying methods were used: air-drying, lyophilization and spray-drying. Air-drying and lyophilization caused β-glucan particles agglomeration and changes of their microstructure. Sonication combined with spray-drying resulted in minimal β-glucan structural changes and negligible formation of agglomerates. Reaggregation of spray-dried β-glucan particles was minimal even after resuspending in water

Karakterizacija β-glukana izoliranih iz pivskoga kvasca te osušenih različitim metodama

Two different procedures have been used for isolation of water-insoluble ß-glucans from brewer’s yeast: alkaline-acidic isolation (AA) and alkaline-acidic isolation with mannoprotein removal (AAM). The obtained ß-glucans were then dried by air-drying, lyophilization and combination of sonication and spray-drying. ß-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 ß-glucan in total polysaccharides were significantly affected by different isolation procedures. Fourier transform infrared (FTIR) spectra of all preparations had the appearance typical for (1→3)-ß-D-glucan. Lyophilization and especially air-drying caused a higher degree of agglomeration and changes in ß-glucan microstructure. Sonication followed by spray-drying resulted in minimal structural changes and negligible formation of agglomerates.Netopljivi β-glukani izolirani su iz pivskoga kvasca primjenom dvaju različitih postupaka: alkalno-kiselinskog (AK) i alkalno-kiselinskog s uklanjanjem manoproteina (AKM). Dobiveni pripravci β-glukana osušeni su na zraku, liofilizacijom i raspršivanjem 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, dušika i kisika određene organskom mikroanalizom. Na udio β-glukana u ukupnim polisaharidima bitno su utjecali različiti postupci izolacije. FT-IR spektri svih pripravaka imali su izgled tipičan za (1→3)-β-D-glukan. Sušenjem na zraku i liofilizacijom došlo je do značajnih promjena strukture čestica i aglomeracije ß-glukana. Sušenje raspršivanjem uz prethodnu obradu ultrazvukom nije dovelo do stvaranja nakupina čestica 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