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 1,477 records · Page 82Linked to original sources

PubMed1989

Biotechnology products: new opportunities and responsibilities for the pharmacist.

The opportunities and responsibilities of pharmacists with respect to the new biotechnology products are described. Recent advances in the fields of molecular genetics and nucleic acid chemistry have resulted in a proliferation of biotechnology products. Those produced by recombinant DNA techniques offer particular promise for the treatment of a wide variety of medical disorders such as cancer, anemia, neutropenia, diabetes, and myocardial infarction. Since the turn of the century, the pharmacy profession has expanded its role from drug preparation and distribution to modern clinical pharmacy, in which pharmacists act as a source of drug information for physicians, nurses, and patients. In response to the new biotechnology revolution, pharmacists must once again undergo a role expansion, this time actively assuming responsibility for educating themselves about the nature and clinical use of the new biopharmaceuticals. The curriculum of students undergoing training in pharmacy should cover such areas as immunoglobulins, immunomodulators, growth hormones, targeted drug-delivery systems, and advanced diagnostic techniques that use biotechnology products. Continuing-education programs in these areas will update currently practicing pharmacists on the new biotechnology products. Although use of biologic proteins is currently targeted toward hospitalized patients, future advances may allow for dispensing these new drugs through community pharmacies as well. Therefore, change will be necessary at all levels of the pharmacy profession. As pharmacists accept the responsibility of dispensing, monitoring, and providing information about the new biotechnologic agents, they will enhance the rational use of these compounds.

Biotechnology↗

PubMed1978

[The manufacture of nystatin-gelatin foils for the treatment of denture stomatitis].

The authors describe the formula and the manufacture of nystatin-gelatin foils that are a new dosage form for local application in case of denture sore mouth induced by Candida albicans. It is pointed to the requirements that a pharmaceutically used gelatin should meet. Furthermore, the authors discuss biopharmaceutical aspects of the nystatin-gelatin foil.

Candidiasis, Oral↗

PubMedDate not supplied

[The effect of modification of excipients for the bioavailability of vinburnine].

Biopharmaceutic comparison is achieved between commercialized capsules of vinburnine and a new dosage form. The difference between the two drug products concerns only the quality of excipients. Drug bioavailability decreases of about 10%, in despite of the very important, and well known, interindividual variations of vincamine drug products. Only the absorption rate seems statistically lightly decreased by the new formulation.

Adult↗

PubMed1986

Pharmacokinetic differentiation and consequences for normal microflora.

The pharmacokinetic properties of a drug are decisive for effective antibacterial therapy, the ability of the drug to reach a site of infection, but they also contribute to whether concentrations become undesirably high in places where the antibiotics are not wanted but where they may interfere with the normal microflora. The microflora in the intestines is particularly important because of the sheer numbers of bacteria present there and the consequences of imbalance such as diarrhoea and selection of bacteria resistant against antibiotics. For these reasons, high intestinal absorption, as can be achieved by the ampicillin prodrugs, is important. This leads to high utilization of the dose and decisively reduces the frequency of loose stools and diarrhoea. Improvement of biopharmaceutical properties of oral dosage forms need combined pharmaceutical and pharmacokinetic assessment. High elimination in the bile can have a considerable impact on the intestinal microflora as, for instance, agents with broad spectrum, like beta-lactamase stable cephalosporins that are not absorbed but remain within the gastrointestinal tract. Cephalosporins have been implicated in the selection of beta-lactamase producing enterobacteria. Narrow spectrum has been a sales argument, but if these agents produce high intestinal concentrations, as is the case with formulations of erythromycin that have poor formulations and are incompletely absorbed, the result may be disturbed faecal flora. In addition to low absorption, erythromycin elimination by bile is high. Clostridium difficile may in particular be selected by high concentrations of antibacterial drugs in the intestines.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorption↗

PubMed1987

Treatment of angina pectoris and hypertension with sustained-release calcium channel-blocking drugs.

Sustained-release diltiazem (D-SR) and sustained-release verapamil (V-SR) when given twice a day have been successfully used to treat both essential hypertension and angina pectoris. Review of available studies indicates that 120 to 180 mg D-SR twice a day and 240 mg V-SR once or twice a day can lower diastolic pressure in 40% to 80% of patients with essential hypertension and that the drugs may be especially useful in patients with low-renin hypertension such as elderly and black populations. D-SR and V-SR prolong treadmill capacity and reduce frequency of angina in patients with stable effort angina. Improvement is mediated primarily by a reduction in resting and submaximal exercise heart rate. Biopharmaceutics of D-SR and V-SR feature a prolonged apparent plasma half-life and reduced peak-to-trough plasma concentration ratios during steady-state dosing.

Angina Pectoris↗

PubMed1986

Synthesis and chemical properties of ibopamine and of related esters of N-substituted dopamines--synthesis of ibopamine metabolites.

The therapeutic usefulness of intravenously infused dopamine in congestive heart failure and in shock prompted us to synthesize a wide series of 3,4-O-diesters of dopamine and N-substituted derivatives to obtain an orally active dopamine-like prodrug having adequate absorption and duration of action. The pharmacological results and in particular, the hemodynamic studies in the dog led to the selection of ibopamine, i.e. the 3,4-diisobutyryl ester of N-methyldopamine and to its development as a useful drug for the chronic treatment of congestive heart failure. The choice of ibopamine from among several analogs was also influenced by other favourable properties such as good chemical stability in pharmaceutical formulations and in the biopharmaceutical phases of the absorption, and fast enzymatic activation of the prodrug by plasma and peripheral tissue esterases; the latter property appeared desirable to avoid any accumulation in the central nervous system and consequent undesired side effects. The isomeric mixture of 3-O- and 4-O-isobutyrates of N-methyldopamine as well as the main conjugated metabolites, i.e. the 3-O- and 4-O-sulphate and 4-O-beta-glucuronide of N-methyldopamine were synthesized as analytical references in metabolic studies and for the investigation on their pharmacokinetic and pharmacological properties. Dopamine O-sulphates were also prepared using the methods developed for the corresponding N-methyl derivatives.

Biotransformation↗

PubMed1986

[Radiation-induced changes in the properties of gelatin].

The impact of high energetic rays between 10 and 100 kGy on gels and solutions of gelatin is studied. Physical and biopharmaceutical properties are changing dependent on the rayage and the content of glycerol and water. The possibilities of influencing melting behaviour, viscosity, rigidity, temperature of gel formation, imbibition behaviour and dissolution in foillike preparations are determined. Glycerol is able to compensate the radioinduced changes of the structure of gelatin up to a dose of 50 kGy. Its use as a radioprotective material is being discussed.

Adsorption↗

PubMed1985

Prednisolone elimination in human saliva.

The elimination of prednisolone in saliva was studied following administration of intravenous doses of 16, 32, 48 and 64 mg to 7 healthy human subjects. While there was an approximate relationship between salivary and plasma concentrations of prednisolone a wide inter- and intraindividual variation in the ratio of the concentration in these two body fluids was observed. Salivary estimations of prednisolone concentration cannot replace plasma concentrations in biopharmaceutical studies.

Adult↗

PubMed1979

Chlorpheniramine. I. Rapid quantitative analysis of chlorpheniramine in plasma, saliva and urine by high-performance liquid chromatography.

A method was developed for the rapid quantitative analysis of chlorpheniramine in plasma, saliva and urine using high-performance liquid chromatography. A diethyl ether or hexane extract of the alkalinized biological samples was extracted with dilute acid which was chromatographed on a reversed-phase column using mixtures of acetonitrile and ammonium phosphate buffer as the mobile phase. Ultraviolet absorption at 254 nm was monitored for the detection and brompheniramine was employed as the internal standard for the quantitation. The effects of buffer, pH, and acetonitrile concentration in the mobile phase on the chromatographic separation were investigated. A mobile phase 20% acetonitrile in 0.0075 M phosphate buffer at a flow-rate of 2 ml/min was used for the assays of plasma and saliva samples. A similar mobile phase was used for urine samples. The drug and internal standard were eluted at retention volumes of less than 17 ml. The method can also be used to quantify two metabolites, didesmethyl- and desmethylchlorpheniramine, in the urine. The method can accurately measure chlorpheniramine levels down to 2 ng/ml in plasma or saliva using 1 ml of sample, and should be adequate for biopharmaceutical and pharmacokinetic studies. Various precautions for using the assay are discussed.

Chlorpheniramine↗

PubMed1981

Antitumor activity of mitomycin C-dextran conjugate against various murine tumors.

The antitumor activity of a high molecular weight pro-drug of mitomycin C(MMC), MMC-dextran conjugate (MMC-D), was examined against various murine tumors under different experimental conditions. A single intraperitoneal injection of MMC-D exhibited higher antitumor activity against intraperitoneally inoculated B16 melanoma, Ehrlich ascites carcinoma, and P388 leukemia than MMC, but lower activity against BDF1 mouse-transplanted L1210 leukemia. Intratumoral injection of MMC-D showed a superior effect on subcutaneously implanted B16 melanoma, while intravenous injection of MMC-D exhibited reduced activity against P388 and L1210 leukemia compared with MMC. Prior administration of MMC-D at 24 hr before tumor inoculation resulted in a significant increase of the life span of mice bearing L1210 leukemia, suggesting that it shows sustained pharmacological activity. These differences between the activities of MMC-D and MMC in various tumor systems are considered to reflect the improved biopharmaceutical properties of MMC-D resulting from the modification of MMC into a polymeric drug.

Animals↗

PubMed1980

[Developmental trends in drug research].

A survey is given on the actual state of drug research and its developmental tendencies. Issuing from an estimation of the present and prospective health-political and economic importance of the drugs the following main subjects of drug research are represented:--Influence on drug research by progressing of knowledge from biosciences,--traditional cooperation between synthesis, chemistry and biological test,--problems in the judgment of activity and security in the application of drugs (indirect side-effects of drugs),--problems in clinical testing of new drugs,--drug monitoring,--biopharmaceutical and galenic research conceptions. As to the fields mentioned the developmental tendencies are described as well as possible effects on the medicamentous therapy in practice are treated.

Angiogenesis Inducing Agents↗

PubMed1983

[Effect of adjuvants on the pharmaceutical and biological availability of chlorpromazine hydrochloride].

It is reported of the influence of adjuvants upon the pharmaceutical and biological availability of chlorpromazine hydrochloride from tablets. Sodium carboxymethyl cellulose, microcrystalline cellulose (Heweten 40) and potato starch have been used for tabletting. The adjuvants added act on the pharmaceutical availability, certain differences being due to a discriminate swelling behaviour. The differences observed in vitro exert no effect on the bioavailability of the drug in the rabbit. Thus, the tablets produced with the adjuvants mentioned have proved to be preparations of almost equivalent similar biopharmaceutical behaviour.

Animals↗

PubMed1984

[Bioavailability of drugs--concepts and problems].

The development of the concept of bioavailability is dealt with on the basis of definitions published in the literature. In this connexion, the often extent divergency between the definition and the determination of bioavailability in practice is indicated. Furthermore, the bioavailability is differentiated from the amount of absorption. With regard to the inclusion of the levels of in vitro liberation, liberation in the body and absorption achieved, the frequently stated use of one and the same term for different contents gives rise to a disentanglement of the terms. Perspectively, the inclusion of animal experimentation in pharmacokinetic-biopharmaceutical investigations is insisted on.

Absorption↗

PubMed1980

Pharmacokinetics of azidocillin in healthy adults.

Two cross-over studies with azidocillin-sodium were carried out on healthy volunteers. In the first, we gave single doses of 375 mg, 750 mg, 1500 mg as tablets, 750 mg as a suspensions, i.m. and i.v. injections of 799 mg, and a course of 750 mg tablets twice daily for 14 days. In the second study, two 750 mg tablet batches were compared with the same dose i.v. Mean peak concentrations after 750 mg as tablets were 6.5-8 microgram/ml, as suspension 12.4 microgram/ml, and i.m. 18.5 microgram/ml. The urinary recovery of active antibiotic was 37-40% of the dose after the tablets, and nearly 50% after i.v. dosage. Thus, urinary elimination after the tablets was 75-83% of the amount eliminated after i.v. dosage. Bioavailabilities stipulated on the basis of the area under serum concentration curves in comparison with i.v. dosage were 57-60% for the tablets and 64% for the suspension. The bioavailability of the i.m. dose was comparable to that of the i.v. injection. The relatively small difference between the tablets and the suspension indicates that the tablets had favourable biopharmaceutical properties. Serum half-life of azidocillin was 0.6-0.7 h after the i.v. doses. For the other dosage forms, the half-life values varied between 0.6 and 1.1 h. The distribution volume Vd,beta ws 27-34 l after i.v. administration.

Adult↗

PubMed1982

[Intramammary drug forms of neotil in treating mastitis during lactation].

Technological, biopharmaceutical, and clinico-pharmacological studies were carried out on the varying composition of drug formulas that included a tylosin base and neomycin sulfate, intended for the treatment of mastitis-affected cows during the lactation period. A base was developed of suitable viscosity and physico-chemical properties, that rapidly released the active ingredients included in it and made them penetrate in depth in the udder glandular tissue. Both the base and the drug formula Neotil were shown to be well tolerated. Following the single intracisternal infusion tylosin was excreted with the milk up to fifth milking (the 60th hour), and neomycin--up to the 4th milking (the 48th hour). When applied therapeutically in the case of clinical and subclinical mastitis Neotil led to the clinical and bacteriological recovery of 92.5 per cent of the affected quarters. Developed was a microbiological method for the analysis of the active ingredients contained in the drug formula and the milk secretion.

Animals↗

PubMed1981

[Bioavailability of theophylline in a new oral sustained-release preparation (author's transl)].

On the basis of biopharmaceutic-pharmacokinetic and galenic aspects a new sustained-release preparation of theophylline according to the "divided-dose" principle was developed. The technological procedure used allows a reproducible manufacture of a stable product with narrow limits of pharmaceutical quality. The bioavailability of the sustained-release pellets in a dose corresponding to 350 mg active principle is examined in comparison to an aqueous solution or retard-tablet formulation on the marked (containing 260 mg drug/dose), respectively, after single or multiple dose administration to 7 healthy volunteers. The relative bioavailability of the new formulation is about 100%. During chronic application the controlled drug delivery from the sustained-release pellets warrants only slight fluctuations of plasma levels by avoiding peak concentrations. Formulations with a dosage of 200, 350 or 500 mg, respectively, allow adaptation of continuous plasma levels in the therapeutic range between 5--20 micrograms/ml according to the therapeutic necessities of a patient.

Adult↗

PubMed1980

[Bioavailability of digoxin tablets in cardiac insufficiency patients].

The bioaccessibility of Soviet produced digoxin tablets in elderly patients with cardiac insufficiency was studied. It is shown that in absolute bioaccessibility (62%) and other biopharmaceutic indices digoxin tablets made in the Soviet Union are equivalent to lanoxin tablets of the Burroughs Wellcome firm which are accepted by the USA FDA as the bioaccessibility standard. Equations fitted within a two-part mathematical model satisfactorily describe the changes in blood serum digoxin concentration in oral medication and in intravenous administration.

Aged↗

PubMedDate not supplied

Quality concept of parenterals in Europe.

Different types of dosage forms are available for parenteral use. They include solutions and suspensions for injection and infusion, sterile powders and lyophilisates which are administered after reconstitution with water for injection or other solutions and finally, controlled-release products (e.g., microparticles or implants). For the quality characterization of the drug products the quality concept of the drug substance has to be considered in addition to the finished product. Several Guidelines on the European basis and others are available, but the harmonisation of the quality concept on an international basis is highly appreciated by pharmaceutical industries. The ICH process is an extremely positive development aiming for a unique chemical and pharmaceutical documentation which can be submitted to all authorities worldwide. Beside the existing standards already internationally harmonised additional aspects will be discussed which include for the quality concept of the drug substance the manufacture and quality control during manufacture and specification of impurities and for the drug products particulate matter tests, specification of content, uniformity of mass and content and the biopharmaceutical characterization.

European Union↗