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Biomedical subjects

R Voigt

Publications and source records attributed to R Voigt.

At least 145 records · Page 8Linked to original sources
PubMed1983

[Effects of the pH value and of drug-adjuvant interactions on the dissolution rate and the liberation of drugs].

It is reported of the effects of the pH value and of drug-adjuvant interactions on the dissolution profile of chlorpromazine hydrochloride and theophylline, as well as on their liberation from triturations with sodium carboxy-methylcellulose and microcrystalline celluloses. The binding of chlorpromazine hydrochloride to sodium carboxymethylcellulose and (less markedly) to micro-crystalline celluloses acts on the drug liberation only in those pH ranges where the dissolution rate of the drug remains constant. In a pH range where the dissolution rate decreases, the binding is of negligible significance. A prolongation of the dissolution time is sufficient to dissolve out the sodium carboxymethylcellulose-bound chlorpromazine hydrochloride from the associate and to produce an increase in liberation. The binding of the drug to the adjuvant weakens with increasing ionic strength of the liberation medium, which leads to a considerable rise of the liberation rate. Owing to the slight sorption of the drug on microcrystalline celluloses, the drug liberation equalizes the dissolution rate in pH ranges greater than 4.8. The dissolution rate of theophylline and the rate of its liberation from triturations showed no differences since there were no drug-adjuvant interactions.

Adjuvants, Pharmaceutic↗
PubMed1982

[Urological investigation in women with stress incontinence prior and following anterior colporrhaphy and in control patients (author's transl)].

The pre-operative and post-operative findings in 56 patients with urinary stress incontinence are compared amongst each other and with the result of 24 continent control patients. The 56 patients were selected prospectively. The urethral closure pressure with stress and the stress quotient in urethral cystometry are significantly improved by the operations. The compliance as a cystometric criterium was significantly raised. The sizes of the angle in the urethrocystogram are at times significantly changed after operation. They are not lower than the values described in the literature. This shows good correlation with the results in the control groups, which have angles higher than those described in the literature. The time parameters of the uroflowmetry show prolongation after the anterior colporrhaphy. The times to the maximum, the waiting time, the urine flow time and the duration of micturition are longer. The mean volume of urine per second is not significantly changed. Our results are compared with other investigations. The findings in healthy continent women are considered to be possible parameters for a reference.

Adult↗
PubMed1982

[Results of uroflowmetry before and after stress incontinence operations].

Reported in this study are urinary flow parameters recorded from patients, prior to and other operations for stress incontinence. These parameters were compared with values obtained from control patients with normal continence. Average urinary flow was found to go up slightly. All other time parameters as well as volumes of micturition were extended or increased, but these changes could not be statistically secured for each of the parameters. The findings are discussed together with information from literature.

Female↗
PubMed1982

[A contribution to the characterization of incompatibilities of drugs with polyethylene glycols and ethoxylated tensides (author's transl)].

The authors studied by means of differential and equilibrium dialysis the interactions of 9 drugs reported in the literature as incompatible with polyethylene glycols (PEG) with PEG 1000 and a non-ionogenic ethoxylated tenside, Brij 35. The purpose of this study was to investigate how far methods such as differential and equilibrium dialysis are suitable for detecting and predicting incompatibilities. Interactions were observed with most of the drug-adjuvant mixtures under study. Brij 35, which has been used as a model substance of non-ionogenic ethoxylated tensides, proved to have a greater binding activity than PEG 1000. The measurable interactions indicate that many incompatibilities known to be manifest continue to exist in another medium in the form of masked incompatibilities.

Chemistry, Pharmaceutical↗
PubMed1982

Pharmacokinetics during pregnancy and delivery.

The pharmacokinetics of certain drugs were studied in the following patient groups: in women in stage III of pregnancy, in women in labor, and in non-pregnant women as a control group. In late gravidity several parameters of distribution and elimination change. Nevertheless, it is not necessary to modify the usual dose schedule. However, sulfonamides and antibiotics should be administered in the upper range of dosage. In contrast to late pregnancy, we found elimination of drugs to be always retarded during labor. Attention must be paid to accumulation, which may occur.

Female↗
PubMed1982

[In the vivo release of drugs from hydrogels].

The in vivo release of chlorpromazine and dioxopromethazine from equiviscous methyl cellulose and polyvinylpyrrolidone hydrogels has been determined in 8 volunteers and brought in relation to results obtained from in vitro studies. For all the individual variations observed, the availability of the drugs was, as a rule, greater from the hydrogels based on the loosely-binding methyl cellulose (e.g., more than doubled) than from the hydrogels based on polyvinylpyrrolidone. Whereas the in vivo and in vitro liberation rates of chlorpromazine (which has a relatively great association power) were of comparable magnitude, the in vivo release of dioxopromethazine was considerably lower as was to be expected considering the results from in vitro studies. Obviously, physico-chemical factors (in the present case, the coefficient of distribution) super-impose the effect of the binding on the bioavailability. Already 10 min after application of the hydrogels, the liberation rate amounted up to 73%.

Biological Availability↗
PubMed1981

[Comparison of preoperative and postoperative findings after stress incontinence surgery in women (author's transl)].

The authors attempt to assess success of surgery in 44 women with stress incontinence treated with colporrhaphia ant. et post. with/without vaginal hysterectomy, by evaluating preoperative and postoperative findings. Examination comprised, after detailed anamnesis, besides general gynaecological examination and examination of urine for pathological constituents, the following methods: simultaneous urethrocystometry, cystometry, urethrocystography, electromyography of the sphincter system, as well as uroflowmetry. It was found that despite subjectively reported success of operation there was often no direct correlation to the actual, objective findings. This underlines once again that assessment of the result of surgery is possible only via application of a wide range of diagnostic procedures postoperatively with the same methods. The results obtained are discussed with reference to reports published in medical literature.

Adult↗
PubMed1981

[Early experience with repeated determinations of 131-I-hipuran clearance-equivalent during pregnancy ].

Serial observations of ureteric and renal function during pregnancy were carried out by using isotope clearances; renal scintigraphy was performed for the first examination and isotope nephrography subsequently. The results of both types of examination are tabulated. It is shown that these procedures provide the necessary information on renal and ureteric function, given the indications which we have listed. The information concerns both kidneys or can be confined to a single kidney.

Adolescent↗