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M Miseta

Publications and source records attributed to M Miseta.

15 recordsLinked to original sources

[Effect of gelatin solution on parameters of tablets containing well-compressible active principles].

Theobromine tablets have been prepared by wet granulation using gelatin solutions of various concentrations. It has been established that film formed from 2 per cent gelatin solution does not assure sufficient binding force. Lamella forming tendency could be observed on tablets. Furthermore, it has been ascertained that tablets proper in respects of both physical parameters and active principle release can be prepared with 5 per cent gelatin solution. It seems to be unnecessary to use 10 per cent gelatin solution. Behaviour of gelatin solutions at compression of starch and their role in active principle release have been discussed. Attention has been drawn to loss of biological value because of the "aging" of the gelatin film.

Gelatin

[Application of beta-cyclodextrin during direct pressing of tablets].

In case of tablets prepared by direct procedure the compressibility of beta-cyclodextrin has been studied. It has been established that beta-cyclodextrin--because of its very good flowing behaviour--can successfully be applied as ingredient in direct pressing. When hardness of tablets has to be increased 20% Avicel pH 101 (VN) has been recommended. By comparative test of 1:1 mol physical mixture of chloramphenicol-beta-cyclodextrin and the granulated product it has been ascertained that method of preparation of products, behaviour of applied solid binding materials and degree of applied pressing force decisively influence the compressibility of products. Furthermore, it has been found that application of beta-cyclodextrin influences advantageously the dissolution rate of active principle from tablets.

Cyclodextrins

[The liberation of phenylbutazone from tablets].

The liberation of phenylbutazone from tablets prepared by wet granulation was examined. It was found that the solution process can be described by the equation c = cs (l-e-K.t alpha). The influence of the binder concentration and the disintegrant on the liberation rate was also studied. The increase of the Klucel MF concentration accelerated the liberation of the agents. Among the disintegrants Polyplasdone XL and cyclodextrin block polymer turned out to be very good.

Drug Compounding

[Direct compression nitrazepam tablets].

Tablets of nitrazepam were made by direct compression. The influence of different dry binders and other adjuvants on the physical parameters of the tablets and their texture (scanning electron microscope: SEM) were examined. Changes in the physical parameter can be explanded if the texture is known.

Drug Compounding

[The polymorphism of drugs in powders and tablets. 1. The preparation and characterization of polymorphic modifications of phenobarbital].

The characterisation of three phenobarbital modifications by thermic examination procedures (DSC, DTA) is being described. Modification I was obtained by thermic treatment of the brands (modification II) from Hungary and the GDR. The spray product prepared, consisting of very fine hollow spheres, was identified as modification III. Besides the particle size distribution the form of the particle was determined by scanning electron microscopy (REM). The best results regarding saturation solubility and speed of dissolution were found for the spray product.

Chemistry, Pharmaceutical

[The polymorphism of drugs in powders and tablets. 4. The effect of the polymorphism of drugs on the physical properties and drug release of phenobarbital tablets].

Four products of phenobarbital (I, II1, II2, III) are manufactured into tablets with the dry binders Avicel PH 101 or Heweten 40 using different pressures by direct tabletting. The physical properties of the resulting tablets are different according to the modification of phenobarbital, the binders used and the pressure during tabletting. The dissolution behaviour of the drug may be changed by the different technological and physical parameters.

Chemical Phenomena

[The use of dry binding materials for the direct compression of phenylbutazone].

Direct compression of phenylbutazone is possible only with addition of excipients of several kinds, because its material properties are unfavourable. It is necessary to use besides disintegrant glidant, lubricant and antistatic agents too. The authors investigated the influence of two microcrystalline cellulose binders (Avicel and Heweten) for the pressability of phenylbutazone and on properties of the tablets, respectively. It was determined the physical parameters of the tablets and the dissolution characteristics of the active ingredient. It has been found, that Heweten optimized the exactness of dosage of the tablets as well as resulted in a faster dissolution than Avicel. Therefore, Heweten proved to be the more suitable binder.

Drug Compounding