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Biomedical subjects

G Regdon

Publications and source records attributed to G Regdon.

At least 37 records · Page 2Linked to original sources

[Formulation and in vitro investigation of antibacterial vaginal suppositories. Part 1. Considerations in selecting the vehicle. Methods and results of the physical examination].

Vaginal suppositories frequently used in gynaecological therapy were studied. Several antibacterial pharmacons are used for the topical treatment of vaginitis of various origins. However, the choice of the vaginal suppository base was often considered to be of minor importance for a long time. In view of the fact that the liberation of the given active substance and the subsequent therapeutic effect may be improved or inhibited by the vehicle, their aim was to find the optimal suppository base for vaginal suppositories containing sulphadimidine, chloramphenicol and gentamicin-sulphate by means of in vitro experiments. On the basis of breaking hardness, disintegration time and spreading properties the French Suppocire NA product, and compositions of macrogols with lower molecular weight proved to be the best lipophilic and hydrophilic bases respectively.

Anti-Infective Agents, Local↗

[Formulation and in vitro investigation of antibacterial vaginal suppositories. Part 2. In vitro membrane diffusion and microbiologic studies].

After the physical parameters had been determined, the in vitro drug liberation from vaginal suppositories containing 100 mg of antibacterial agent (sulphadimine, chloramphenicol, gentamicin-sulphate) was studied by membrane diffusion and microbiological methods. Among the vehicles available in Hungary the hydrophylic Massa macrogoli was found to be the best for this purpose. Among the lipophilic bases the in vitro drug liberation of the French Suppocire NA product was significantly better (p < 0.05) compared to the other lipophilic bases. This vehicle is recommended by the authors for the topical treatment of vaginitis, as these suppositories have the further advantage that they can easily be produced on a magistral, galenical or industrial scale as well. In the first part of the publication the formulation and some important physical parameters of lipophilic and hydrophilic antibacterial suppositories for vaginal use were described. In the present paper the drug liberation ability of the compositions with proper physical parameters was studied. The published results were obtained from measurements performed 1 week after formulation.

Anti-Infective Agents, Local↗

[Biopharmaceutical importance of pharmaceutical aids in drug prescribing with special reference to rectal administration].

Based on literary sources, the medical and pharmaceutical significance of vehicles and additives, which play an ever-increasing role in the production of all drug forms, is discussed. Then the groups of additives used in the production of suppositories are described partly on the basis of our own experiences, and their biopharmaceutical significance is evaluated.

Drug Compounding↗

[Formulation and analysis of suppositories containing papaverine hydrochloride. Part 1. Choice of the optimal vehicle and determination of the physical parameters of the suppositories].

Suppositories containing 0.10 g papaverine hydrochloride were made with moulding technology to produce spasmolytic effect. The optimal vehicle was tried to be found for these suppositories. During the experiments 12 different suppository masses were used, including lipophil and lipohydrophil vehicles as well as vehicles with low and high hydroxyl numbers. Five different kinds of physical parameters were determined: melting and drop points, disintegration and special penetration times and breaking hardness. The physical parameters of suppositories without active substance and containing papaverine were examined separately. After 6 months of storage the greater part of the masses showed unfavourable changes (after-hardening, increase of the disintegration time, etc.). In the end the Estaram 299 mass, a triglyceride type of mass with a low hydroxyl number was found satisfactory in every respect, either in itself or combined with 5% Estasan neutral oil.

Chemical Phenomena↗

[Formulation and analysis of suppositories containing papaverine hydrochloride. Part 2. In vitro membrane diffusion studies].

Rectal suppositories with 0.10 g/2.0 g Papaverine hydrochloride content were made with 12 different vehicles. The membrane diffusion method was used to study the factors influencing the in vitro drug liberation. The Polysorbate 20 and 61 tenside pair, the optimal concentration of which was 5% each, was found to influence diffusion favourably. Neutral oils softening the consistency (Miglyol 812 and Estasan), similarly in 5%, also had a favourable effect on the in vitro diffusion by increasing the spreading properties. As to the lipophil suppository masses with high and low hydroxyl numbers, only the latter could be used favourably. The 6-month-long storage resulted in drug retention in several experimental series. Correlation was found in several cases between the physical parameters of the suppositories and their in vitro drug liberation. Finally, with the help of linear regression calculation and in view of the in vitro relative bioavailability values the optimal vehicle is suggested for the formulation of suppositories containing Papaverine hydrochloride. The triglyceride type Estaram 299 was found to be the most suitable in every respect, either in itself or combined with 5% neutral oil.

Diffusion↗

[Preparation of theophylline-sodium salicylate suppositories and determination of factors influencing the in vitro dissolution of the active agents].

Suppositories of theophylline-sodium salicylate were prepared with 10 different vehicles and also with tensids and softeners. With the dynamic diffusion method the drug dissolution and the in vitro diffusion were measured. It was established that proper choice of the vehicle is very important. The highest relative in vitro availability was measured in the case of glyceride base with low hydroxyl value. The diffusion of the active agent can be described by an exponential function.

Chemical Phenomena↗

[Biopharmaceutical study of aminophenazone-containing suppositories. 1. Experimental materials and methods, determination of physical qualities of the suppositories].

Suppositories containing aminophenazone in quantities of 0.30 g/2 g were prepared by pouring technology. Two kinds of lipophilic suppository masses Witepsol W 35 and Estarinum 299 have been used as vehicles. Both of suppository bases are official in Ph. Hg. VII. As ingredients ten sorts of liquid tensides in concentrations of 5% have been applied. Experimental methods have been described: compression stability, disintegration time, special penetration time and drug release of suppositories by membrane diffusion method. Results of determinations have been discussed in the second part of the publication. On the basis of experimental results it has been established that the physical parameters of Massa Estarinum 299 had proved to be more advantageous. In 5% concentrations tensides softened consistency of suppositories favorably and shortened disintegration time beneficially in the case of both vehicles. The authors think that special penetration time is more suitable for measuring "disintegration" of suppositories of high powder content at 37 degrees C than the classical disintegration time.

Aminopyrine↗

[Biopharmaceutical study of aminophenazone-containing suppositories. 2. Results of in vitro drug release and in vivo drug absorption].

Ten kinds of surface active ingredients of Th. Goldschmidt AG. (Essen-FRG) in concentrations of 5% were mixed with Witepsol W 35 and Massa Estarinum 299 suppository masses of Hüls-Troisdorf AG. Werk (Witten-FRG) which are official in Hungary. According to the authors the above tensides, which have been used advantageously first of all in ointments, creams and cosmetic preparations, can also be applied in rectal preparations. In the publication of two parts it has been established that these ingredients influence physical parameters of suppositories beneficially. They always increase significantly in vitro diffusion values and in some cases with order of magnitude. Massa Estarinum 299 containing 5% of Emulgator BTO proved to be the best in case of chosen suppositories containing aminophenazone. Correlation between in vitro and in vivo investigations has shown the importance of correct selection of base and ingredient materials in biopharmaceutical work.

Aminopyrine↗

[Rheologic investigation of electrode gels. III. Study of temporal changes of gel structure].

In the publication consisting of 3 parts nine electrode gels have been investigated siú of them are used in hospital pharmacies of this country. Character and stability of gel structure have been studied and controlled by rheological methods. Structural forces have been numerically characterized with maximum and equilibrium viscosity, values of "M and B coefficients" and directional tangents of viscosity curves. Mechanical and thermal stability have been determined, changes for six months storing have been studied by means of all rheological parameters, respectively. Besides investigating rheological parameters electric conductivity values--which are important in respect of practical use of electrode gels--have been determined too. On the basis of results Carbopol "G" designated gel has been found to be the best its use has been proposed not only in supersonic tests but also in ECG.

Electrocardiography↗

[Rheologic investigation of electrode gels. II. Mechanical and thermal stability].

In the publication consisting of 3 parts nine electrode gels have been investigated six of them are used in hospital pharmacies of this country. Character and stability of gel structure have been studied and controlled by rheological methods. Structural forces have been numerically characterized with maximum and equilibrium viscosity, values of "M and B coefficients" and directional tangents of viscosity curves. Mechanical and thermal stability have been determined, changes for six months storing have been studied by means of all rheological parameters, respectively. Besides investigating rheological parameters electric conductivity values--which are important in respect of practical use of electrode gels--have been determined too. On the basis of results Carbopol "G" designated gel has been found to be the best its use has been proposed not only in supersonic tests but also in ECG.

Electrochemistry↗

[Preparation and in vitro study of suppositories containing No-Spa. II. Determination of release of the active principle by membrane diffusion methods].

The authors have made proposal of pharmaceutical technology of a well storable, excellent drug release No-Spa./suppository besides No-Spa./tablets and injection have been in circulation in this country. Without Estaram 299 of small hydroxyl value or combined with 10% ESTASAN oil it suits to therapeutical expectations in every respect. Physical parameters of suppositories and chemical stability of drotaverinium chloride have been excellent on the basis of one year storing. On the ground of in vitro investigations the suppository has been proposed to be introduced to human therapy as antispasmodic preparation.

Diffusion↗

[Rheologic investigation of electrode gels].

Nine electrode gels have been investigated 6 of them are used in hospital pharmacies of this country. The results were compared to properties of two gels from abroad, the recommended electrode gel has been developed on this basis. Character of formed gel structure has been studied by flow curves and structural forces have been numerically characterized by determining the parameters of the function made linear. By determination of electric conductivity the proposed Carbopol gel has been found suitable not only to supersonic tests but also to ECG and may be to EEG.

Electrocardiography↗