Semisynthetic and synthetic polymers have found their use in the technology of hydrophilic matrix systems with controlled release of the active ingredient, in particular in oral administration. In the recent period, there is increased interest also in natural polymeric substances, whose advantage consists in safety, easy availability, and a relatively low price. They thus represent an interesting possibility to extend the selection of novel constitutive auxiliary substances. The present review paper surveys the most important natural polymers: alginans, carageens, Arabic gum, pectins, galactomanans, ispaghul, and xantan gum as potential carriers for oral hydrophilic systems with controlled release of active ingredients and describes its origin, properties, and possible uses in pharmacy.

• MeSH
• biopolymery * MeSH
• farmaceutická chemie MeSH
• léky s prodlouženým účinkem * MeSH
• tablety * MeSH
• Publikační typ
• anglický abstrakt MeSH
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• biopolymery * MeSH
• léky s prodlouženým účinkem * MeSH
• tablety * MeSH

Hydrophilic matrix tablets based on hydroxypropylmethylcellulose (HPMC) and other cellulose derivatives rank among dosage forms with retarded effect widely used in contemporary pharmacotherapy. The active ingredient is released from them in dependence on its properties either by dissolution and diffusion, or erosion of the compact. The dissolution profile of the active ingredient can be influenced by variables of formulation and manufacture, e.g. by the type of HPMC employed, its concentration, other added auxiliary substances, and compression force which is reflected in the strength of tablets. Two drugs with different solubility were used to study the effect of drug solubility on its release from matrices: well soluble diltiazemium chloride and badly soluble ibuprofen. Higher solubility of the drug and lower solubility of compacts resulted in more rapid release of the active ingredient. Also lower concentration of HPMC accelerates the release of both drugs. The effect of the degree of viscosity of the polymer on drug release was not markedly manifested.

• MeSH
• diltiazem chemie   MeSH
• farmaceutická chemie MeSH
• ibuprofen chemie   MeSH
• kardiovaskulární látky chemie   MeSH
• laktosa analogy a deriváty   MeSH
• léky s prodlouženým účinkem MeSH
• methylcelulosa analogy a deriváty   MeSH
• oxaziny MeSH
• rozpustnost MeSH
• tablety MeSH
• Publikační typ
• anglický abstrakt MeSH
• časopisecké články MeSH
• Názvy látek
• diltiazem MeSH
• ibuprofen MeSH
• kardiovaskulární látky MeSH
• laktosa MeSH
• léky s prodlouženým účinkem MeSH
• methylcelulosa MeSH
• MK 458 MeSH Prohlížeč
• oxaziny MeSH
• tablety MeSH

This review focuses on the characterization of (meth)acrylate copolymers - Eudragit®, describing their thermal treatment behaviour, possible interactions between cationic and anionic polymers, incompatibilities related to Eudragits® and their use in the pharmaceutical technology of oral tablets. In summary, Eudragit® copolymers are divided into soluble ones, insoluble ones and a combination of these two types. The combination of soluble and insoluble poly(meth)acrylate gave a new type of polymer, Eudragit® FL. In oral tablet technology, Eudragits® are widely used in matrix tablets, either alone or in combination, where they mainly provide sustained drug release. To a lesser extent, Eudragits® are used in gastroretentive systems. Moreover, Eudragits® are also of great importance in coated tablets technology, where these enteric polymers provide specific drug targeting to certain parts of the digestive tract, mainly to the small intestine or colon. Important systems such as CODESTM and MMX® technology are mentioned. Last but not least an overview table of currently available oral medicinal products on the Czech market, where at least one of the Eudragits® was used as a film-forming agent, is included.

• Klíčová slova
• Eudragit®, acidoresistant tablets, burst effect, colon drug delivery, film-coating tablets, floating tablets, matrix tablets, prolonged drug release,
• MeSH
• farmaceutická chemie * MeSH
• kyseliny polymethakrylové chemie   MeSH
• léky s prodlouženým účinkem MeSH
• rozpustnost MeSH
• tablety * MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• kyseliny polymethakrylové MeSH
• léky s prodlouženým účinkem MeSH
• methylmethacrylate-methacrylic acid copolymer MeSH Prohlížeč
• tablety * MeSH

The aim of this study is to present the possibility of using of co-processed dry binders for formulation of matrix tablets with drug controlled release. Hydrophilic matrix tablets with tramadol hydrochloride, hypromellose and different co-processed dry binders were prepared by direct compression method. Hypromelloses Methocel™ K4M Premium CR or Methocel™ K100M Premium CR were used as controlled release agents and Prosolv® SMCC 90 or Disintequik™ MCC 25 were used as co-processed dry binders. Homogeneity of the tablets was evaluated using scanning electron microscopy and energy dispersive X-ray microanalysis. The release of tramadol hydrochloride from prepared formulations was studied by dissolution test method. The dissolution profiles obtained were evaluated by non-linear regression analysis, release rate constants and other kinetic parameters were determined. It was found that matrix tablets based on Prosolv® SMCC 90 and Methocel™ Premium CR cannot control the tramadol release effectively for >12h and tablets containing Disintequik™ MCC 25 and Methocel™ Premium CR >8h.

• Klíčová slova
• Co-processed dry binders, Dissolution kinetics, Hypromellose, Matrix tablets, Tramadol hydrochloride,
• MeSH
• deriváty hypromelózy chemie   farmakokinetika   MeSH
• farmaceutická chemie metody   MeSH
• hydrofobní a hydrofilní interakce * MeSH
• rozpustnost MeSH
• tablety MeSH
• tramadol chemie   farmakokinetika   MeSH
• uvolňování léčiv MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• deriváty hypromelózy MeSH
• tablety MeSH
• tramadol MeSH

UNLABELLED: Eudragit® NM was investigated as a matrix former in combination with microcrystalline cellulose as an insoluble filler for preparing controlled-release tablets containing model drugs with different solubility. MATERIAL AND METHODS: Three sets of matrix tablets differing in the drug-to-filler ratio (1:1, 2:1, and 4:1) and polymer amount with diltiazem hydrochloride (freely soluble) or caffeine (sparingly soluble) were prepared. Samples were evaluated by the dissolution test at pH 6.8 corresponding to the upper part of the small intestine; the selected samples were tested at a changing pH level to better simulate in vivo conditions. RESULTS: The prepared matrix tablets fulfilled all the requirements of the European Pharmacopoeia. Tablets with Eudragit® NM showed excellent mechanical characteristics. In vitro studies showed that the set 1:1 was the most suitable for the sustained release of a freely soluble drug concerning the burst effect and the total drug amount released within 12 hours. The significant effect of the drug-to-filler ratio and polymer amount on the dissolution profile was confirmed by similarity factor analysis. A faster drug release was observed during the dissolution test within changing pH levels because of the pH-dependent solubility of diltiazem. A prolonged release of the sparingly soluble drug was not achieved, and a trend for fast disintegration was observed. CONCLUSIONS: The combination of Eudragit®NM with microcrystalline cellulose as an insoluble filler seems to be suitable only for freely soluble drugs, when the amount of the drug and the filler is similar.

• MeSH
• celulosa chemie   MeSH
• kyseliny polymethakrylové chemie   MeSH
• léky s prodlouženým účinkem chemie   MeSH
• racionální návrh léčiv * MeSH
• rozpustnost MeSH
• tablety MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• celulosa MeSH
• kyseliny polymethakrylové MeSH
• léky s prodlouženým účinkem MeSH
• methylmethacrylate-methacrylic acid copolymer MeSH Prohlížeč
• tablety MeSH

The paper focuses on the formulation of HPMC K-matrix tablets by compression of granulates previously prepared by melt granulation. The model drug was theophylline monohydrate. Montanglycol wax was used as the solid lipid binder in a concentration of 10-20 %. With respect to the obtained results, thermoplastic granulation was found to ensure suitable porosity, flow, and particle size of the granulates. In both dissolution media (phosphate buffer pH 6.8 and artificial gastric juice pH 1.2), the release of the model drug is dependent on the HPMC viscosity grade used. The release rate can be modified by a change in the HPMC-to-montanglycol wax ratio. A decrease in this ratio increases the liberation of theophylline monohydrate. Due to different drug solubilities in the selected dissolution media, theophylline is released significantly faster in phosphate buffer pH 6.8 then in artificial gastric juice pH 1.2. The matrices of the same composition were prepared by direct compression; the comparison of dissolution profiles shows that the release of the active substance is not influenced by the employed method of manufacture.

• MeSH
• farmaceutická chemie MeSH
• farmaceutická technologie * MeSH
• léky s prodlouženým účinkem * MeSH
• tablety * MeSH
• theofylin MeSH
• Publikační typ
• anglický abstrakt MeSH
• časopisecké články MeSH
• Názvy látek
• léky s prodlouženým účinkem * MeSH
• tablety * MeSH
• theofylin MeSH

This paper evaluates and compares the properties of directly compressible tabletting materials and matrix tablets containing a combination of α-lactose monohydrate and microcrystalline cellulose in the 3:1 ratio in a physical mixture and in a coprocessed dry binder. Tested parameters include flow properties, compressibility, compactibility and the rate of drug release from tablets. Compressibility is evaluated by means of the energy profile of the compression process. Compactibility is evaluated by means of the tensile strength of the tablets. Dissolution testing is done using the rotating basket method. Dissolution profiles are evaluated by non-linear regression analysis. Total energy of compression and plasticity values were higher in tabletting materials with the coprocessed dry binder. Increasing additions of polyvinyl alcohol decreased the values of total energy of compression, plasticity, tensile strength of tablets and drug release rate. Dissolution behaviour of tablets, which contained the physical mixture or coprocessed dry binder and the same amount of polyvinyl alcohol, was comparable.

• Klíčová slova
• coprocessed dry binder, dissolution testing, energy profile of compression, matrix tablets, polyvinyl alcohol, tensile strength of tablets,
• MeSH
• celulosa chemie   MeSH
• farmaceutická chemie metody   MeSH
• farmaceutická technologie metody   MeSH
• kyselina salicylová aplikace a dávkování   chemie   MeSH
• laktosa chemie   MeSH
• nelineární dynamika MeSH
• pevnost v tahu MeSH
• polyvinylalkohol chemie   MeSH
• pomocné látky chemie   MeSH
• rozpustnost MeSH
• tablety MeSH
• uvolňování léčiv MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH
• Názvy látek
• celulosa MeSH
• kyselina salicylová MeSH
• laktosa MeSH
• microcrystalline cellulose MeSH Prohlížeč
• polyvinylalkohol MeSH
• pomocné látky MeSH
• tablety MeSH

Matrix tablets with a dispersed active ingredient are the simplest concept in the design of dosage forms with modified drug release. If they contain a swelling polymer as an auxiliary substance, the release from these systems, after initial liberation of a portion of the active ingredient from the surface, takes place by diffusion, erosion, or a combination of both mechanisms in dependence on the solubility of the contained active ingredient. Although hydrophilic matrix tablets have become a well-tried and widely used dosage form with retarded effects, their research continues and new auxiliary substances and their combinations are being tested. The present paper reviews the knowledge published in this field in recent years.

• MeSH
• farmaceutická chemie MeSH
• farmaceutické pomocné látky * MeSH
• gely MeSH
• léky s prodlouženým účinkem MeSH
• polymery * MeSH
• tablety * MeSH
• Publikační typ
• anglický abstrakt MeSH
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• farmaceutické pomocné látky * MeSH
• gely MeSH
• léky s prodlouženým účinkem MeSH
• polymery * MeSH
• tablety * MeSH

The objective of the present research is to evaluate directly compressible chitosan-based tableting materials for the formulation of mucoadhesive matrix tablets intended for targeted drug release to distal segments of the GIT. The influence of sodium alginate, hypromellose, and silicified microcrystalline cellulose (P90) on compressibility, compactability and lubricant sensitivity ratio was tested. Furthermore, the rheological properties of the hydrated surface layer of the matrix tablets and the mucoadhesion to a mucin substrate were analysed. Compressibility was evaluated using the energy profile of the compression process, compactability by means of the tensile strength of tablets, and lubricant sensitivity ratio was calculated to assess the sensitivity to lubricant. Addition of P90 to chitosan improved compressibility, which is demonstrated by the increase in the energy of plastic deformation and the higher tensile strength of tablets. P90 also significantly reduced the high lubricant sensitivity of chitosan. Presence of retarding components led to a decrease in Emax. All tested matrix tablets revealed a good mucoadhesion without a negative effect of P90 content. The viscosity of a gel layer on the surface of matrix tablets containing hypromellose was higher compared to those with sodium alginate. This was not reflected in the adhesive strength of the tablets. The formulated tableting materials combining chitosan and P90 are a suitable matrix for incorporation of an active ingredient, whose delayed release in the intestine can be achieved by the functionality of the chitosan-sodium alginate complex.

• Klíčová slova
• chitosan, compactability, compressibility, matrix tablets, mucoadhesion, silicified microcrystalline cellulose,
• Publikační typ
• časopisecké články MeSH

The purpose of this experimental work was the development of hydrophilic-lipophilic matrix tablets for controlled release of slightly soluble drug represented here by diclofenac sodium (DS). Drug dissolution profile optimization provided by soluble filler was studied. Matrix tablets were based on cetyl alcohol as the lipophilic carrier, povidone as the gel-forming agent, and common soluble filler, that is lactose or sucrose of different particle size. Physical properties of tablets prepared by melt granulation and drug release in a phosphate buffer of pH 6.8 were evaluated. In vitro studies showed that used filler type, filler to povidone ratio and sucrose particle size influenced the drug release rate. DS dissolution profile could be changed within a wide range from about 50% per 24 hours to almost 100% in 10 hours. The release constant values confirmed that DS was released from matrices by the diffusion and anomalous transport. The influence of sucrose particle size on the drug release rate was observed. As the particle size decreased, the drug release increased significantly and its dissolution profile became more uniform. Soluble fillers participated in the pore-forming process according to their solubility and particle size. Formulations containing 100 mg of the drug, 80 mg of cetyl alcohol, 40 mg of povidone, and 80 mg of either lactose or sucrose (particle size 250-125 microm) were considered optimal for 24-hour lasting dissolution of DS.

• MeSH
• antiflogistika nesteroidní aplikace a dávkování   chemie   MeSH
• časové faktory MeSH
• diklofenak aplikace a dávkování   chemie   MeSH
• laktosa chemie   MeSH
• léky s prodlouženým účinkem MeSH
• mastné alkoholy chemie   MeSH
• nosiče léků chemie   MeSH
• pomocné látky chemie   MeSH
• povidon chemie   MeSH
• rozpustnost MeSH
• sacharosa chemie   MeSH
• tablety MeSH
• velikost částic MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antiflogistika nesteroidní MeSH
• cetyl alcohol MeSH Prohlížeč
• diklofenak MeSH
• laktosa MeSH
• léky s prodlouženým účinkem MeSH
• mastné alkoholy MeSH
• nosiče léků MeSH
• pomocné látky MeSH
• povidon MeSH
• sacharosa MeSH
• tablety MeSH