Research and development in health care industry is in persistence progression. To make it more patient-friendly or to get maximum benefits from it, special attention to different advanced drug delivery system (ADDS) is employed that delivers the drug at the target site and will be able to sustain/control release of drugs. ADDS should be non-toxic, biodegradable, biocompatible along with desirable showing physicochemical and functional properties. These drug delivery systems can be totally based on polymers, either with natural or synthetic polymers. The molecular weight of polymer can be tuned and different groups of polymers can be modified or substituted with other functional groups. Degree of substitution is also tailored. Cationic starch in recent years is exploited in drug delivery, tissue engineering and biomedicine. Due to their abundant availability, low cost, easy chemical modification, low toxicity, biodegradability and biocompatibility, extensive research is now being carried out. Our present discussion will shed light on the usage of cationic starch in health care system.
- MeSH
- kationty chemie MeSH
- lékové transportní systémy MeSH
- lidé MeSH
- polymery * chemie MeSH
- polysacharidy chemie MeSH
- poskytování zdravotní péče MeSH
- škrob * chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Škrob je biopolymer, obsažený v rostlinách a řasách. V zelených rostlinách se tvoří při fotosyntéze v chloroplastech jako tzv. tranzitní škrob, který je v průběhu temné fáze transportován v podobě rozpustných sacharidů do zásobních orgánů rostlin, kde je opět převe‐ den do podoby škrobových zrn. Tato opětná syntéza se liší pro jednoděložné a dvouděložné rostliny. Průmyslově izolovaný škrob má řadu využití, hlavní roli hraje enzymová hydrolýza na sirupy, které pak mohou být výchozí látkou pro celou řadu dalších biochemických transformací. Článek se věnuje rovněž nutričním aspektům škrobu, především jeho stravitelností. Je popsán základní princip enzymo‐ vých metod ke stanovení obsahu celkového škrobu, obsahu amylosy, rychle a pomalu stravitelného škrobu a škrobu rezistentního.
Starch is a biopolymer found in plants and algae. In green plants, it is formed during photosynthesis in the chloroplasts as so ‐called transitory starch, which is transported during the dark phase in the form of soluble carbohydrates to the storage organs of plants, where it is again converted into the form of starch granules. This repeated synthesis is different for monocots and dicots. Industria‐ lly isolated starch has a number of uses, the main role is played by enzyme hydrolysis into syrups, which can then be the starting material for a whole range of subsequent biochemical transformations. The article also deals with the nutritional aspects of starch, especially its digestibility. The basic principle of enzyme methods to determine the content of total starch, amylose content, rapidly and slowly digestible starch and resistant starch is described.
This review summarizes and broadly classifies all of the major sustainable natural carbohydrate bio-macromolecular manifestations in nature - from botanical (cellulose, starch, and pectin), seaweed (alginate, carrageenan, and agar), microbial (bacterial cellulose, dextran, and pullulan), and animal (hyaluronan, heparin, chitin, and chitosan) sources - that have been contrived into electrospun fibers. Furthermore, a relative study of these biomaterials for the fabrication of nanofibers by electrospinning and their characteristics viz. solution behavior, blending nature, as well as rheological and fiber attributes are discussed. The potential multidimensional applications of nanofibers (filtration, antimicrobial, biosensor, gas sensor, energy storage, catalytic, and tissue engineering) originating from these polysaccharides and their major impacts on the properties, functionalities, and uses of these electrospun fibers are compared and critically examined.
- MeSH
- agar chemie MeSH
- algináty chemie MeSH
- biokompatibilní materiály chemie MeSH
- celulosa chemie MeSH
- chitin chemie MeSH
- chitosan chemie MeSH
- dextrany chemie MeSH
- elektrochemické techniky MeSH
- glukany chemie MeSH
- heparin chemie MeSH
- karagenan chemie MeSH
- kyselina hyaluronová chemie MeSH
- lidé MeSH
- nanotechnologie metody MeSH
- nanovlákna chemie ultrastruktura MeSH
- pektiny chemie MeSH
- škrob chemie MeSH
- tkáňové inženýrství metody MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Due to the additional particle coalescence in the coating, changes in the dissolution profile occur over time in the formulations coated by aqueous ethylcellulose latex. Dry thermal treatment (DT) of the coating can be used as a prevention of this process. Alternatively, it is advisable to take advantage of the synergistic effect of high humidity during wet treatment (WT), which substantially accelerates the film formation. This can be a problem for time-controlled systems, which are based on the coating rupture due to the penetration of water into the core causing the increase in the system volume. This process can begin already during the WT, which may affect the coating adversely. The submitted work was focused on the stability testing of two pellet core compositions: pellets containing swelling superdisintegrant sodium carboxymethyl starch (CMS) and pellets containing osmotically active polyethylene glycol (PEG). Another objective was to identify the treatment/storage condition effects on the pellet dissolution profiles. These pellets are intended to prevent hypoglycemia for patients with diabetes mellitus and therefore, besides the excipients, pellet cores contain 75% or 80% of glucose. The pellet coating is formed by ethylcellulose-based latex, which provides the required lag time (120-360 min). The sample stability was evaluated depending on the pellet core composition (PEG, CMS) for two types of final pellet coating treatment (DT or WT). Scanning electron microscopy and Raman microspectroscopy revealed the penetration of glucose and polyethylene glycol from the core to the PEG pellet surface after WT. For the CMS sample, significant pellet swelling after WT (under the conditions of elevated humidity) was statistically confirmed by the means of stereomicroscopic data evaluation. Therefore, the acceleration of dissolution rate during the stress tests is caused by the soluble substance penetration through the coating in the case of PEG pellets or by dosage form volume increase in the case of CMS pellets. The observed mechanisms can be generally anticipated during the stability testing of the ethylcellulose coated dosage forms. The aforementioned processes do not occur after DT and the pellets are stable in the environment without increased humidity.
- MeSH
- celulosa analogy a deriváty chemie MeSH
- farmaceutická chemie MeSH
- glukosa chemie farmakologie MeSH
- hypoglykemie prevence a kontrola MeSH
- implantované léky chemie MeSH
- léky s prodlouženým účinkem MeSH
- polyethylenglykoly chemie MeSH
- pomocné látky chemie MeSH
- povrchové vlastnosti MeSH
- příprava léků metody MeSH
- rozpustnost MeSH
- škrob analogy a deriváty chemie MeSH
- stabilita léku MeSH
- uvolňování léčiv MeSH
- velikost částic MeSH
- vysoká teplota MeSH
- Publikační typ
- časopisecké články MeSH
Starch is the most widely used bio-based biodegradable polymer. This contribution briefly reviews basic information about natural starch and focuses on preparation, properties and applications of thermoplasticized starch (TPS). We present a literature review and, in addition, we show our recent results: the reliable and reproducible preparation method yielding highly homogeneous TPS and the TPS-based blends for local controlled release of antibiotics.
CONTEXT: The preparation of liquisolid systems (LSS) represents a promising method for enhancing a dissolution rate and bioavailability of poorly soluble drugs. The release of the drug from LSS tablets is affected by many factors, including the disintegration time. OBJECTIVE: The evaluation of differences among LSS containing varying amounts and types of commercially used superdisintegrants (Kollidon® CL-F, Vivasol® and Explotab®). MATERIALS AND METHODS: LSS were prepared by spraying rosuvastatin solution onto Neusilin® US2 and further processing into tablets. Varying amounts of superdisintegrants were used and the differences among LSS were evaluated. The multiple scatter plot method was used to visualize the relationships within the obtained data. RESULTS AND DISCUSSION: All disintegrants do not showed negative effect on the flow properties of powder blends. The type and concentration of superdisintegrant had an impact on the disintegration time and dissolution profiles of tablets. Tablets with Explotab® showed the longest disintegration time and the smallest amount of released drug. Fastest disintegration and dissolution rate were observed in tablets containing Kollidon® CL-F (≥2.5% w/w). Also tablets with Vivasol® (2.5-4.0% w/w) showed fast disintegration and complete drug release. CONCLUSION: Kollidon® CL-F and Vivasol® in concentration ≥2.5% are suitable superdisintegrants for LSS with enhanced release of drug.
- MeSH
- anticholesteremika aplikace a dávkování chemie MeSH
- farmaceutické pomocné látky chemie MeSH
- povidon chemie MeSH
- příprava léků MeSH
- rosuvastatin kalcium aplikace a dávkování chemie MeSH
- rozpustnost MeSH
- silikáty chemie MeSH
- škrob analogy a deriváty chemie MeSH
- sloučeniny hliníku chemie MeSH
- sloučeniny hořčíku chemie MeSH
- tablety chemie MeSH
- uvolňování léčiv MeSH
- Publikační typ
- časopisecké články MeSH
Composites of thermoplastic starch (TPS) with titanium dioxide particles (mTiO2; average size 0.1μm) with very homogeneous matrix and well-dispersed filler were prepared by a two-step method, including solution casting (SC) followed by melt mixing (MM). Light and scanning electron microscopy confirmed that only the two-step procedure (SC+MM) resulted in ideally homogeneous TPS/mTiO2systems. The composites prepared by single-step MM contained non-plasticized starch granules and the composites prepared by single-step SC suffered from mTiO2agglomeration. Dynamic mechanical measurements showed an increase modulus with increasing filler concentration. In TPS containing 3wt.% of mTiO2the stiffness was enhanced by >40%. Further experiments revealed that the recommended addition of chitosan or the exchange of mTiO2for anisometric titanate nanotubes with high aspect ratio did not improve the properties of the composites.
- MeSH
- mechanické jevy * MeSH
- plastické hmoty chemie MeSH
- reologie * MeSH
- škrob chemie MeSH
- teplota * MeSH
- titan chemie MeSH
- Publikační typ
- časopisecké články MeSH
Patients tend to evade the occurrence of hypoglycemic episodes by excessive carbohydrate intake. Glucose pellets with delayed release in the time of the maximum effect of insulin can not only prevent hypoglycemia but also eliminate the preventive carbohydrate intake. The pellets can be administered in a mixture with semisolid food. The cores containing glucose in combination with osmotically active agents (croscarmellose sodium, carmellose sodium, polyethylene glycol, or carboxymethyl starch) were prepared by extrusion-spheronization and coated with 15% water ethylcellulose dispersion (Surelease® B NF) in Wurster column (Medipo, Havlíčkův Brod, Czech Republic) into four coating levels (12.5, 25, 35, and 50%). Mean particle size is 0.63-0.73 for cores and 0.82-0.98 for coated pellets. Cores and coated pellets have excellent or good flow properties according to Hausner ratio and Carr index. Aspect ratio ranges from 1.78 to 2.17 for cores and from 1.73 to 2.31 for coated pellets. Dissolution was performed using pH-independent method and method with continual change of pH. The suitable pH-independent release was achieved in the samples containing carboxymethyl starch or polyethylene glycol. Glucose release is enabled by a membrane rupture caused by core swelling. It can be, therefore, assumed that the glucose release profile will not be affected by food or transit time.
- MeSH
- celulosa analogy a deriváty chemie MeSH
- diabetes mellitus farmakoterapie MeSH
- dítě MeSH
- farmaceutická chemie metody MeSH
- glukosa aplikace a dávkování MeSH
- hypoglykemie farmakoterapie MeSH
- hypoglykemika aplikace a dávkování MeSH
- implantované léky aplikace a dávkování MeSH
- lékové formy MeSH
- lékové transportní systémy metody MeSH
- léky s prodlouženým účinkem aplikace a dávkování chemie MeSH
- lidé MeSH
- polyethylenglykoly chemie MeSH
- pomocné látky chemie MeSH
- rozpustnost MeSH
- škrob analogy a deriváty chemie MeSH
- velikost částic MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Patients tend to prevent hypoglycemia by excessive saccharide intake leading to poorer glycemic control with potentially fatal consequences. This problem could be resolved by means of pellets with glucose release delayed by 120-360 min as a compensation of the antidiabetic drug peak effect. No glucose is released before; hence there is no risk of hyperglycemia and secondary complications. The pellets contain glucose in combination with an osmotically active ingredient and are coated with an ethylcellulose dispersion, which forms an insoluble semipermeable membrane and ensures delayed release. The release of glucose was assessed using dissolution and high-performance liquid chromatography. Dissolution profiles indicated the possibility of achieving the requested lag time using a combination of adequate compositions and coating concentrations. Lag times of 60, 240 and 360 min were achieved. The sample containing carboxymethyl starch was found to be most suitable for the intent of this work.
- MeSH
- celulosa analogy a deriváty chemie MeSH
- glukosa aplikace a dávkování chemie MeSH
- hypoglykemie krev prevence a kontrola MeSH
- kinetika MeSH
- krevní glukóza metabolismus účinky léků MeSH
- léky s prodlouženým účinkem MeSH
- lidé MeSH
- membrány umělé MeSH
- pomocné látky chemie MeSH
- povrchové vlastnosti MeSH
- příprava léků MeSH
- rozpustnost MeSH
- škrob chemie MeSH
- vysokoúčinná kapalinová chromatografie MeSH
- Check Tag
- lidé MeSH
