PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “BIOPHARMACEUTICS”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 631 records · Page 35Linked to original sources
PubMed2003

Development and biopharmaceutical evaluation of osmotic pump tablets for controlled delivery of diclofenac sodium.

Based on the principles of an elementary osmotic pump (OP), OP tablets were designed and evaluated with the aim to deliver diclofenac sodium (DS) in a controlled manner. In vitro evaluation was done in various release media and kinetics was evaluated using the regression coefficient analysis. Effects of orifice size, coating membrane type, coating thickness, static and stirred conditions and pH variation were studied. In vivo evaluation was performed on six healthy human volunteers and various pharmacokinetic parameters (c(max), t(max), AUC(0-24), MRT) and relative bioavailability were calculated. The results were compared with the performance of two commercial tablets of DS. The drug release from OP tablets was dependent on the type and thickness of the coating membrane, but was independent of the orifice size and static and stirred conditions of the release medium. The OP tablets provided a prolonged and controlled DS release compared to commercial sustained-release and conventional tablets of DS.

Administration, Oral↗
PubMed2003

[Rheological and biopharmaceutical investigation of polymer drug delivery systems].

Drug release of watersoluble active agent (ephedrine hydrochloride) and water-insoluble ones (griseofulvine, salicylic acid, sulfadimidine) from hydrogels containing different polymers was investigated. The rheological behaviour of polymer matrices was characterized by flow curves and viscosity curves. These hydrogels were not thixotropic systems, unlike more authors' statement. The values of rheological constants increase exponentially with concentration of polymers. The liberation of active agents can be characterized by a multiplicative function. The constant of viscosity vs. concentration function was determined and it was called as characteristic of structure formation. A linear relationship between constant of structure formation and drug liberation was demonstrated.

Chemistry, Pharmaceutical↗
PubMed2005

Biopharmaceutical evaluation of oral tablet Atenolol (100 and 50 mg) on local population.

An open-label, randomized study was designed to determine the bioavailability (BA); pharmacokinetic (PK) and pharmacodynamic (PD) behaviour of Atenolol 50 mg (two pills) and 100 mg (one pill) tablet manufactured by a national pharmaceutical industry. Peak plasma concentration (Cmax): 1.33 +/- 0.31 microg/ml, time to peak plasma concentration (Tmax): 2.2 +/- 0.27 hours, AUC (area under the plasma concentration-time curve) 6.34 +/- 2.1 microg-hr/ml for 100 mg tab and Cmax: 1.07 +/- 0.23 microg/ml, Tmax: 2.5 +/- 0.35 hours, AUC 4.97 +/- 1.09 microg-hr/ml for 50 mg (two pills) tab were observed. The BA and PK parameters such as Cmax, Tmax, are comparable to previous studies, although significant decrease in diastolic and systolic blood pressure (mmHg) upto a certain limit for a considerable duration was observed. However, relation between PK and PD may not be established due to regulatory biochemical feedback mechanism.

Administration, Oral↗
PubMed2006

Detection breadth and limits for potential adventitious/endogenous contaminants in biopharmaceutical processes: a reality check for innovative methods.

In this presentation we address the "gold standards" among diagnostic tests used to detect some potential adventitious and endogenous contaminants in human biologics and vaccines, reflecting on the breadth as well as limits of detection of these assays. This perspective may help developers of innovative diagnostics to address the unique needs of this highly regulated industry.

Bacteria↗
PubMed1991

Biopharmaceutic evaluation of furosemide as a potential candidate for a modified release peroral dosage form.

An attempt was made to evaluate some of the criteria for developing a modified release peroral dosage form for furosemide which has a poor bioavailability when given in the conventional peroral dosage forms. The pathway of absorption for furosemide was studied ex vivo employing the Wilson-Wiseman test. Passive absorption was found to be the predominant mechanism of transport across the ileum of the guinea pig followed by active transport to the extent of about 17%. The in situ procedure to study the extent of absorption of furosemide from the various sites in the lumen of the gastrointestinal tract of the rat indicated the stomach to be the major site of absorption followed by the duodenum. It is hence postulated that due to the site-specificity and mechanism of absorption a peroral modified release dosage form having a longer gastric residence time could possibly increase the bioavailability of furosemide.

Administration, Oral↗
PubMed1990

[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↗
PubMed1990

Biopharmaceutical studies of 3-substituted isatin derivatives.

The metabolic fate of isatin hydrazone (Ia), isatin-3-thiosemicarbazone (Ib), isatin-3-semicarbazone (Ic), isatin-3-phenylhydrazone (Id), isatin oxime (Ie) and 3-hydroxy-3-acetonyl oxindole (II) was studied in rabbits. The compounds were administered orally in the dose of 300 mg/kg body wt. Isatin anthranilic acid, tryptophan and nicotinic acid were identified as the major metabolites excreted in urine. The 3-hydroxy-3-acetonyl oxindole (II) gave on additional metabolite, oxindole. The major metabolites were separated and identified unambiguously on thin layer silica gel plate. Metabolic pathways have been proposed to explain the biotransformation of the compounds investigated.

Animals↗
PubMed1987

Biopharmaceutical aspects of FK-506.

FK is a potent immunosuppressive agent. FK can be analyzed in biologic fluids by EIA. The oral absorption of FK is rapid but variable in dogs. After intramuscular administration, FK is slowly and continuously absorbed. FK is primarily eliminated by metabolism. Less than 1% of the administered dose is excreted in the bile or the urine. After chronic intramuscular administration FK inhibits drug metabolism. Monitoring of FK levels in plasma is essential for the proper interpretation of efficacy and toxicity studies.

Administration, Oral↗
PubMedDate not supplied

Biopharmaceutical characterization of 450191-S, a ring-opened derivative of 1,4-benzodiazepine. II. Evidence for reduced first-pass extraction by rat liver.

The new hypnotic, 5-[(2-aminoacetamido)methyl]-1-[p-chloro-2-(o- chlorobenzoyl)phenyl]-N,N-dimethyl-1H-1,2,4-triazole-3-carboxamide hydrochloride dihydrate (450191-S), is a ring-opened derivative of 1,4-benzodiazepine that is activated by spontaneous cyclization via a labile desglycylated metabolite (191DG). Pharmacokinetic comparison between 450191-S and its primary active metabolite, 8-chloro-6-(2-chlorophenyl)-N,N-dimethyl-4H-1,2,4-triazole[1,5-a][1,4] benzodiazepine-2-carboxamide (M-1), in rats revealed that higher levels of active metabolites were produced after 450191-S administration. To find the causes for this, in vivo and in vitro experiments were performed with the focus on hepatic uptake. Study of the absorption and distribution of radioactivity after intraduodenal administration of [14C]450191-S and [14C]M-1 revealed that most of the radioactivity was in the liver, with absorption of M-1 being rapid regardless of the dose and the absorption of 450191-S being slower at higher doses. Comparison of the portal and systemic metabolite levels showed the hepatic first-pass extraction after M-1 administration to be more effective than that after 450191-S administration. This was attributed to the labile intermediate, 191DG, which reduced the first-pass extraction in the liver. This reduction was confirmed by pharmacokinetic analysis after portal injection of 191DG in vivo and by incubation with liver slices in vitro. Thus, the presence of 191DG improved the bioavailability of active metabolites after 450191-S administration.

Animals↗
PubMedDate not supplied

The recovery of highly purified biopharmaceuticals from perfusion cell culture bioreactors.

The impact of continuous perfusion cell culture technology on production of one and two chain human rtPA, as well as monoclonal IgG and IgM, will be reviewed. Perfusion as compared to batch systems improve the quality of the product in the conditioned media in terms of biological activity and structural integrity. This significantly increases downstream recovery and daily production output of final purified material. These findings are a consequence of the ability of perfusion technology to 1) maintain cells intact at high cell density; 2) effectively reduce serum content to approximate serum free conditions; and 3) minimize residency time of labile product within the 37 degrees C environment of the bioreactor.

Biological Products↗