Ciklodekstrini –primjena u različitim načinima isporuke lijekova

The objective of this review article is to explain the use of cyclodextrin in the different routes of drug administration. The article gives the chemistry of cyclodextrins and addresses the issue of the mechanism of drug release from cyclodextrin complexes. Dilution, competitive displacement, protein binding, change in ionic strength and temperature and drug uptake by tissues are the different release mechanisms of the drug from the drug-cyclodextrin complex discussed here. Use and its limitations in the different drug delivery systems like nasal, ophthalmic, transdermal and rectal drug delivery are explained. The application of the cyclodextrins in the oral drug delivery is detailed in this review. Many studies have shown that cyclodextrins are used as useful additives in the routes of drug administration because of increased aqueous solubility, stability, bioavailability and reduced drug irritation.U ovom revijalnom radu opisana su fizičko-kemijska svojstva ciklodekstrina, različiti načini njihove primjene te mehanizmi oslobađanja ljekovitih tvari iz kompleksa s ciklodekstrinima (razrjeđenje, kompetitivna zamjena, vezanje na proteine, promjena ionske jakosti i temperature te unos ljekovite tvari u tkivo). Opisana je uporaba ciklodekstrina i ograničenja uporabe u različitim sustavima za isporuku lijekova za nazalnu, oftalmičku, transdermalnu, rektalnu te detaljno za peroralnu primjenu. Mnogobrojna istraživanja su potvrdila da su ciklodekstrini korisni sastojci pripravaka za različite načine primjene jer povećavaju vodotopljivost, stabilnost i bioraspoloživost ljekovite tvari, a smanjuju njenu iritabilnost

Priprava i evaluacija plutajućih matriksa rizedronat natrija Gelucire® 39/01

Incorporation of bisphosphonates in the lipid reduces gastric irritation. Only gastric retention with sustained release allows the drug to reach the duodenum and jejunum and improves the availability of bisphosphonates. Risedronate sodium and Gelucire® 39/01 floating matrices were prepared using melt solidification. The sustained release floating matrices were evaluated for in vitro and in vivo floating ability and in vitro drug release. Ageing of the matrices was studied by differential scanning calorimetry, hot stage polarizing microscopy, scanning electron microscopy and in vitro drug release. Ageing causes changes in the crystal structure of the Gelucire®, which is responsible for increase in drug release.Uklapanje bisfosfonata u lipide smanjuje iritaciju želuca. Samo zadržavanje u želucu s usporenim oslobađanjem omogućava da ljekovita tvar dospije u duodenum i jejunum i povećava bioraspoloživost bisfosfonata. Rizedronat natrij i Gelucire® 39/01 plutajući matriksi pripravljeni su metodom taljenja i očvršćivanja. Proučavana je sposobnost plutanja pripremljenih matriksa in vitro i in vivo te oslobađanje ljekovite tvari. Starenje matriksa proučavano je diferencijalnom pretražnom kalorimetrijom, polarizirajućom mikroskopijom s vrućom pločom i pretražnom elektronskom mikroskopijom. Starenje uzrokuje promjene u kristalnoj strukturi Gelucire® zbog kojih se povećava oslobađanje ljekovite tvari

Priprava i evaluacija plutajućih matriksa rizedronat natrija Gelucire® 39/01

Incorporation of bisphosphonates in the lipid reduces gastric irritation. Only gastric retention with sustained release allows the drug to reach the duodenum and jejunum and improves the availability of bisphosphonates. Risedronate sodium and Gelucire® 39/01 floating matrices were prepared using melt solidification. The sustained release floating matrices were evaluated for in vitro and in vivo floating ability and in vitro drug release. Ageing of the matrices was studied by differential scanning calorimetry, hot stage polarizing microscopy, scanning electron microscopy and in vitro drug release. Ageing causes changes in the crystal structure of the Gelucire®, which is responsible for increase in drug release.Uklapanje bisfosfonata u lipide smanjuje iritaciju želuca. Samo zadržavanje u želucu s usporenim oslobađanjem omogućava da ljekovita tvar dospije u duodenum i jejunum i povećava bioraspoloživost bisfosfonata. Rizedronat natrij i Gelucire® 39/01 plutajući matriksi pripravljeni su metodom taljenja i očvršćivanja. Proučavana je sposobnost plutanja pripremljenih matriksa in vitro i in vivo te oslobađanje ljekovite tvari. Starenje matriksa proučavano je diferencijalnom pretražnom kalorimetrijom, polarizirajućom mikroskopijom s vrućom pločom i pretražnom elektronskom mikroskopijom. Starenje uzrokuje promjene u kristalnoj strukturi Gelucire® zbog kojih se povećava oslobađanje ljekovite tvari

Classification of COVID-19 Cases: The Customized Deep Convolutional Neural Network and Transfer Learning Approach

The recent advancements under the umbrella of artificial intelligence (AI) open opportunities to tackle complex problems related to image analysis. Recently, the proliferation of COVID-19 brought multiple challenges to medical practitioners, such as precise analysis and classification of COVID-19 cases. Deep learning (DL) and transfer learning (TL) techniques appear to be attractive solutions. To provide the precise classification of COVID-19 cases, this article presents a customized Deep Convolutional Neural Network (DCNN) and pre-trained TL model approach. Our pipeline accommodated several popular pre-trained TL models, namely DenseNet121, ResNet50, InceptionV3, EfficientNetB0, and VGG16, to classify COVID-19 positive and negative cases. We evaluated and compared the performance of these models with a wide range of measures, including accuracy, precision, recall, and F1 score for classifying COVID-19 cases based on chest X-rays. The results demonstrate that our customized DCNN model performed well with randomly assigned weights, achieving 98.5% recall and 97.0% accuracy

Ciklodekstrini –primjena u različitim načinima isporuke lijekova

The objective of this review article is to explain the use of cyclodextrin in the different routes of drug administration. The article gives the chemistry of cyclodextrins and addresses the issue of the mechanism of drug release from cyclodextrin complexes. Dilution, competitive displacement, protein binding, change in ionic strength and temperature and drug uptake by tissues are the different release mechanisms of the drug from the drug-cyclodextrin complex discussed here. Use and its limitations in the different drug delivery systems like nasal, ophthalmic, transdermal and rectal drug delivery are explained. The application of the cyclodextrins in the oral drug delivery is detailed in this review. Many studies have shown that cyclodextrins are used as useful additives in the routes of drug administration because of increased aqueous solubility, stability, bioavailability and reduced drug irritation.U ovom revijalnom radu opisana su fizičko-kemijska svojstva ciklodekstrina, različiti načini njihove primjene te mehanizmi oslobađanja ljekovitih tvari iz kompleksa s ciklodekstrinima (razrjeđenje, kompetitivna zamjena, vezanje na proteine, promjena ionske jakosti i temperature te unos ljekovite tvari u tkivo). Opisana je uporaba ciklodekstrina i ograničenja uporabe u različitim sustavima za isporuku lijekova za nazalnu, oftalmičku, transdermalnu, rektalnu te detaljno za peroralnu primjenu. Mnogobrojna istraživanja su potvrdila da su ciklodekstrini korisni sastojci pripravaka za različite načine primjene jer povećavaju vodotopljivost, stabilnost i bioraspoloživost ljekovite tvari, a smanjuju njenu iritabilnost

Ispitivanje vosku sličnih svojstava ibuprofena kao veziva

The study investigates ibuprofen with wax-like properties as a multifunctional agent (as an active component and as a melt binder). Binding efficiency was compared with granules prepared by wet granulation using polyvinylpyrollidone (PVP K-30) as a binder for micromeritic, physical and mechanical properties such as angle of repose, particle size distribution Carr’s index, Hausner’s ratio, crushing strength, percentage fines, Heckel plot study and tensile strength. To check the binder distribution during melt granulation, content uniformity was determined. To check changes in the physical state of ibuprofen, XRPD, DSC and FTIR studies were carried out. The present study underlines the fact that ibuprofen may be adopted as a binder in ibuprofen formulations using the melt granulation techniqueSvrha rada je ispitivanje vosku sličnih svojstava ibuprofena, tvari s višeznačnom funkcijom (ljekovita tvar i vezivo pri granulaciji). Vezivna svojstva uspoređivana su s granulama pripravljenim vlažnom granulacijom s polivinilpirolidonom (PVP K-30) kao vezivom, ispitivanjem mikrometričkih, fizikalnih i mehaničkih svojstava kao što su sipkost materijala, Carrov indeks distribucije veličine čestica, Hausnerov parameter, otpornost na vlak. Da bi se ispitala distribucija veziva tijekom granulacije taljenjem određivana je ujednačenost sadržaja. Za praćenje promjena fizikalnih svojstava ibuprofena snimljeni su XRPD, DSC, FTIR spektri. Istraživanja ukazuju da se ibuprofen može koristiti kao vezivo u ljekovitim pripravcima ibuprofena u kojima se primjenjuje granulacija taljenjem

Ispitivanje vosku sličnih svojstava ibuprofena kao veziva

The study investigates ibuprofen with wax-like properties as a multifunctional agent (as an active component and as a melt binder). Binding efficiency was compared with granules prepared by wet granulation using polyvinylpyrollidone (PVP K-30) as a binder for micromeritic, physical and mechanical properties such as angle of repose, particle size distribution Carr’s index, Hausner’s ratio, crushing strength, percentage fines, Heckel plot study and tensile strength. To check the binder distribution during melt granulation, content uniformity was determined. To check changes in the physical state of ibuprofen, XRPD, DSC and FTIR studies were carried out. The present study underlines the fact that ibuprofen may be adopted as a binder in ibuprofen formulations using the melt granulation techniqueSvrha rada je ispitivanje vosku sličnih svojstava ibuprofena, tvari s višeznačnom funkcijom (ljekovita tvar i vezivo pri granulaciji). Vezivna svojstva uspoređivana su s granulama pripravljenim vlažnom granulacijom s polivinilpirolidonom (PVP K-30) kao vezivom, ispitivanjem mikrometričkih, fizikalnih i mehaničkih svojstava kao što su sipkost materijala, Carrov indeks distribucije veličine čestica, Hausnerov parameter, otpornost na vlak. Da bi se ispitala distribucija veziva tijekom granulacije taljenjem određivana je ujednačenost sadržaja. Za praćenje promjena fizikalnih svojstava ibuprofena snimljeni su XRPD, DSC, FTIR spektri. Istraživanja ukazuju da se ibuprofen može koristiti kao vezivo u ljekovitim pripravcima ibuprofena u kojima se primjenjuje granulacija taljenjem

Physical and magnetic properties of barium calcium hexaferrite nano-particles synthesized by water-in-oil reverse micelle and co-precipitation techniques

BaCaB2BFeB16BOB27B hexaferrite particles were prepared using two different techniques namely (i) reverse micelle and (ii) co-precipitation with and without presence of surfactants (cationic, anionic and nonionic). The precipitate was calcinated at 950EsC for 4 hours and characterized by using various instrumental techniques. The structural studies of the samples were studied by using XRD and SEM. The field dependent magnetic properties of prepared Ba-Ca hexaferrite powder was investigated at room temperature by using vibrating sample magnetometer. It has been observed that the type of surfactant plays a crucial role in deciding the morphology of the particles. There is significant change in crystallite size of the resultant Ba-Ca hexaferrite prepared in presence of anionic surfactant sodium dodecyl sulfate (SDS) and reverse micelle route. The samples prepared in presence of cationic and non ionic surfactants show agglomerated large particles. Magnetic study reveals that the value of anisotropy constant (K) depends on the type of surfactant used. The sample prepared in presence of nonionic surfactant Polyethylene glycol sorbitan monooleate (Tween 80) shows low anisotropy constant (0.26×10P-3P HAP2P/kg) where as the sample prepared in presence of SDS surfactant exhibits high anisotropy constant (3.26×10P-3P HAP2P/kg) compared to normal sample (0.41 ×10P-3P HAP2P/kg)

Pharmaceutical screen identifies novel target processes for activation of autophagy with a broad translational potential

Autophagy is a conserved homeostatic process active in all human cells and affecting a spectrum of diseases. Here we use a pharmaceutical screen to discover new mechanisms for activation of autophagy. We identify a subset of pharmaceuticals inducing autophagic flux with effects in diverse cellular systems modelling specific stages of several human diseases such as HIV transmission and hyperphosphorylated tau accumulation in Alzheimer’s disease. One drug, flubendazole, is a potent inducer of autophagy initiation and flux by affecting acetylated and dynamic microtubules in a reciprocal way. Disruption of dynamic microtubules by flubendazole results in mTOR deactivation and dissociation from lysosomes leading to TFEB (transcription factor EB) nuclear translocation and activation of autophagy. By inducing microtubule acetylation, flubendazole activates JNK1 leading to Bcl-2 phosphorylation, causing release of Beclin1 from Bcl-2-Beclin1 complexes for autophagy induction, thus uncovering a new approach to inducing autophagic flux that may be applicable in disease treatment

L Band Brightness Temperature Observations over a Corn Canopy during the Entire Growth Cycle

During a field campaign covering the 2002 corn growing season, a dual polarized tower mounted L-band (1.4 GHz) radiometer (LRAD) provided brightness temperature (TB) measurements at preset intervals, incidence and azimuth angles. These radiometer measurements were supported by an extensive characterization of land surface variables including soil moisture, soil temperature, vegetation biomass, and surface roughness. In the period May 22 to August 30, ten days of radiometer and ground measurements are available for a corn canopy with a vegetation water content (W) range of 0.0 to 4.3 kg m−2. Using this data set, the effects of corn vegetation on surface emissions are investigated by means of a semi-empirical radiative transfer model. Additionally, the impact of roughness on the surface emission is quantified using TB measurements over bare soil conditions. Subsequently, the estimated roughness parameters, ground measurements and horizontally (H)-polarized TB are employed to invert the H-polarized transmissivity (γh) for the monitored corn growing season