Effect of chitosan on a periodontal pathogen Porphyromonas gingivalis.

Local delivery systems of antimicrobial agents for treatment of the periodontal diseases received considerable attention during the past decade due to the disadvantages of the systemic administration. An ideal formulation should exhibit ease of delivery, a good retention at the application site, and a controlled release of the drug. The application of bioadhesive gels provides a long stay in the oral cavity, adequate drug penetration, high efficacy and acceptability. In dentistry and oral medicine, various applications of chitosan, which is a bioadhesive polymer have been proposed due to its favorable properties such as biocompatibility and biodegradability. The aim of this study was to determine the antimicrobial activity of chitosan formulations either in gel or film form against a periodontal pathogen, Porphyromonas gingivalis. The viscosity, bioadhesive properties and antimicrobial activity of chitosans at different molecular weight and deacetylation degree were evaluated in the absence or presence of chlorhexidine gluconate (Chx), incorporated into the formulations at 0.1 and 0.2% concentrations. The flow property of the gels were found to be suitable for topical application on the oral mucosa and to syringe into the periodontal pocket. Bioadhesion of the gels and films examined ex-vivo using fresh porcine buccal mucosa showed that both the film and gel formulations exert bioadhesive properties and was not affected by incorporation of Chx. Chitosan is shown to have an antimicrobial activity against P. gingivalis and this was higher with high molecular weight chitosan. The combination of chitosan with Chx showed a higher activity when compared to that of Chx alone, which would provide Chx application at lower concentrations thus avoiding its unwanted side effects. Chitosan films and gels seem to be promising delivery systems for local therapy of periodontal diseases with its bioadhesive property and antimicrobial activity.

Approaches to education of pharmaceutical biotechnology in faculties of pharmacy.

Pharmaceutical biotechnology is developing rapidly both in academic institutions and in the biopharmaceutical industry. For this reason, FIP Special Interest Group of Pharmaceutical Biotechnology decided to develop a questionnaire concerning pharmaceutical biotechnology education. After preliminary studies were completed, questionnaires were sent to the leading scientists in academia and research directors or senior managers of various Pharmaceutical Biotechnology Companies in order to gather their views about how to create a satisfactory program. The objectives of this study were as follows: -To review all of the graduate and undergraduate courses which are presently available worldwide on pharmaceutical biotechnology in Faculties of Pharmacy. -To review all of the text books, references and scientific sources available worldwide in the area of pharmaceutical biotechnology. When replying to the questionnaires, the respondents were asked to consider the present status of pharmaceutical biotechnology education in academia and future learning needs in collaboration with the biotechnology industry. The data from various pharmacy faculties and biotechnology industry representatives from Asia, Europe and America were evaluated and the outcome of the survey showed that educational efforts in training qualified staff in the rapidly growing field of pharmaceutical biotechnology is promising. Part of the results of this questionnaire study have already been presented at the 57th International Congress of FIP Vancouver, Canada in 1997.

Enhancing effect of chitosan on peptide drug delivery across buccal mucosa.

The buccal mucosa represents a potentially important topical route for delivery of peptide or protein drugs with some unique advantages such as the avoidance of hepatic first-pass metabolism and the acidity and protease activity encountered in the gastrointestinal tract. However, the bioavailabilities or relative potencies of intraorally administered peptides are usually quite low, unless permeabilizers are employed. Chitosan, a mucopolysaccharide of marine origin, has been claimed to act both as a bioadhesive and permeabilizer, making it a candidate system for mucosal drug delivery. In this study, the enhancement effect of chitosan in gel form for oral mucosa was investigated with a large bioactive peptide, transforming growth factor-beta (TGF-beta). Chitosan gel was prepared at 2% concentration in dilute lactic acid and TGF-beta was incorporated into the gel. The effect of chitosan as a permeabilizer was determined by measuring the flux of TGF-beta across porcine oral mucosa in an in vitro system. The localization of TGF-beta within the oral mucosa was determined by horizontal sectioning and counting. Chitosan was found to exert a marked permeabilizing effect on buccal mucosa for peptide drug.

Chitosan films and hydrogels of chlorhexidine gluconate for oral mucosal delivery.

Topical delivery of antimicrobial agents is the most widely accepted approach aimed at prolonging active drug concentrations in the oral cavity. As most antifungals do not posses inherent ability to bind to the oral mucosa, this is best achieved through improved formulations. Chitosan, a partially deacetylated chitin, which is a biologically safe biopolymer, prolongs the adhesion time of oral gels and drug release from them. Chitosan also inhibits the adhesion of Candida albicans to human buccal cells and has antifungal activity. The antifungal agent, chlorhexidine gluconate (Chx), also reduces C. albicans adhesion to oral mucosal cells. The aim of this study was to design a formulation containing chitosan for local delivery of Chx to the oral cavity. Gels (at 1 or 2% concentration) or film forms of chitosan were prepared containing 0.1 or 0.2% Chx and their in vitro release properties were studied. The antifungal activity of chitosan itself as well as the various formulations containing Chx was also examined. Release of Chx from gels was maintained for 3 h. A prolonged release was observed with film formulations. No lag-time was observed in release of Chx from either gels or films. The highest antifungal activity was obtained with 2% chitosan gel containing 0.1% Chx.

A population-based perspective of changes in health-related quality of life after myocardial infarction in older men and women.

This study analyzes changes in health-related quality-of-life (HQL) outcomes following myocardial infarction (MI) from a population-based perspective. Data came from a representative sample of 2812 men and women 65 years and older living in New Haven, CT. All subjects were interviewed at baseline in 1982, and again in 1985 and 1988. HQL outcomes included self-rated health, depressive symptoms, and physical and social functioning. Pooled logistic regression models were used to estimate the risk for decline in HQL outcomes due to MI. Of the 203 MIs during follow-up, 111 (55%) survived until the next interview to provide post-MI data on outcomes. In bivariate analysis, MI patients were more likely than subjects without MI to show a decline in physical functioning (26.4% vs. 11.9%, P = .001) and social functioning (31.4% vs. 20.8%), P = .06). There were no differences in self-rated health (26.3% vs. 26.9%), but MI patients were less likely to show an increase in depression (9.1%) vs. 15.8%, P = .08). These associations remained mostly unchanged after adjustment for CHD risk factors. The effect of MI on physical and social functioning was much stronger among patients with a recent MI (<1 year ago) than those whose MI had occurred more than a year before post-MI assessment. While a substantial proportion of MI patients experience a significant decline in quality of life-related outcomes, only some of these declines occur more frequently among MI patients than in the population at large. This effect may also be limited to the immediate post-MI period. Results from this analysis are discussed in terms of the "burden of illness" within a defined population due to MI.

[Czech physicians--numismatists]. / Cestí lékari--numismatici.

The article contains information on the life and work of six distinguished Czech numismatists from the ranks of doctors. They raised the standard of Czech numismatics and spread its fame abroad. In addition to their highly skilled medical activities they were foremost experts in numismatics.

Sustained release isoniazid tablets. I--Formulation and in vitro evaluation.

Isoniazid (INH) has been widely used in the preventive therapy of tuberculosis since the early 1950's. The aim in designing a sustained release tablet form was to attain in fast inactivators sustained blood concentrations similar to those produced by ordinary INH tablets in slow acetylators during chemotherapy. In the present paper, the release of INH incorporated into three different matrix materials, polymethylmethacrylates, polyvinyl chloride and carbomer were studied. The release rate of a unit dose of conventionally formulated INH tablets was used as a basis of comparison. The best sustained effect on the release rate of INH was obtained with 30% carbomer matrix tablets.