Preparation and evaluation of sustained release microballoons of propranolol

The purpose of the present investigation was to characterize, optimize and evaluate microballoons of Propranolol hydrochloride and to increase its boioavailability by increasing the retention time of the drug in the gastrointestinal tract. Propranolol hydrochloride-loaded microballoons were prepared by the non-aqueous O/O emulsion solvent diffusion evaporation method using Eudragit RSPO as polymer. It was found that preparation temperature determined the formation of cavity inside the microballoon and this in turn determined the buoyancy. Microballoons were subjected to particle size determination, micromeritic properties, buoyancy, entrapment efficiency, drug loading, in vitro drug release and IR study. The correlation between the buoyancy, bulk density and porosity of microballoons were elucidated. The release rate was determined in simulated gastric fluid [SGF] of pH 1.2 at 37 +/- 0.5 °C. The microballoons presented spherical and smooth morphologies [SEM] and were porous due to presence of hollow cavity. Microballoons remained buoyant for >12 hrs for the optimized formulation. The formulation demonstrated favorable in vitro floating and release characteristics. The encapsulation efficiency was high. In vitro dissolution kinetics followed the Higuchi model. The drug release from microballoons was mainly controlled by diffusion and showed a biphasic pattern with an initial burst release, followed by sustained release for 12 hrs. The amount of the drug which released up to 12 hrs was 82.05 +/- 0.64%. Statistical analysis [ANOVA] showed significant difference [p < 0.05] in the cumulative amount of drug released after 30 min, and up to 12 hrs from optimized formulations. The designed system for propanolol would possibly be advantageous in terms of increased bioavailability and patient compliance

Dental erosion and its risk factors in 12-year-old school children in Mashhad

The dental hard tissues might be destroyed by different factors. One is dental erosion defined as the progressive loss of hard dental tissues by a chemical process not involving bacterial action. The purpose of this study was to determine the prevalence of dental erosion and its risk factors in 12-year-old school children. This cross-sectional study was carried out on 483 12-year-old school children in Mashhad, 2007. Dental erosion was recorded for the labial and palatal surfaces of the upper incisors. For measurement purposes, the O'sullivan's index was adopted, and the results were statistically analyzed by T-student and Chi-Square tests. The prevalence of dental erosion was 38.1%, with no significant sex difference. Dental erosion was significantly higher in private school children [P < 0.001] and in underprivileged areas [P = 0.005]. Matt appearance of the enamel was the most prevalent type of dental erosion [21.2% central incisors, 5.2% lateral incisors]. In most of the involved cases, more than half of their surfaces were diagnosed as affected by erosion [24.4% central incisors, 5.2% lateral incisors]. The frequency consumption of carbonated beverages and night drinks illustrated a significant relation with dental erosion [P = 0.01, P = 0.023]. Children who swam professionally in swimming pools had significantly higher dental erosion [P < 0.001]. Based on the findings of this study, individually tailored preventive programs may be recommended to patients and a comprehensive case history should be taken so that all risk factors can be revealed

Assessment of helicobacter pylori viability by flow cytometry

Flow cytometry is a rapid, sensitive, and reliable method for determination of bacterial viability. Here we assayed the capability of flow cytometry to detect Helicobacter pylori viable cells in both forms of spiral and coccoid. Viable bacteria stained with Rhodamin 123 and fluoresced with laser beam of 488nm. The rate of Rh123 absorption was determined in both forms of bacteria. In positive control that consisted of live bacteria, the rate of rh123 absorption was at highest, but negative control that consisted of dead bacteria, the rate of Rh 123 absorption was at lowest absorption. This method showed that non-culturable coccoid forms of H. pylori, which could resist environmental stresses, were alive and might be responsible for bacterial transmission and failure in disease treatment. Due to simplicity, reliability, and sensitivity of flow cytometry, this method is preferred to other expensive and no reliable methods such as autoradiography, PCR and Electron microscopy used for assessment viability

Prevalence of hepatitis C virus among out patients of a private laboratory in Tehran

With an estimated 170 million infected individuals, hepatitis C virus [HCV] has a major impact on public health. Frequency of HCV infection was studied in 785 referred patients to a private Laboratory, Tehran, Iran from April 2003 until March 2006 by PCR method. Analyzed results revealed infection rate was 40.27%, 35.51% and 33.09% in the first, second and third year, respectively. Frequency rate of the infection shows a fluctuated shape during months of three years. Maximum rate of the HCV infection was in May of the first and in June of the second and third year, respectively. It shows decrease and increase within rest months in each year. HCV infection rate was higher in 31 to 40 years old group of patients. Analysis of the data revealed higher HCV infection in men than women had. It was concluded that HCV frequency pattern underlines specific attention to suspected patients during high rate time

[ relationship between diet and oral hygiene and gingival status in private preschool children in the city of Mashhad]

The purpose of this study was to evaluate the relationship between diet and oral and gingival hygiene stata in preschool children. In this corss-sectional study, 250 preschool children [105 boys and 145 girls] aged 4-6.5 years old, were randomly selected among private kindergartens in Mashhad. The data were collected through questionnaire and clinical examination, and diet, OHI-S and PMA indices were evaluated. The data were analyzed statistically by chi-square test and Kendell correlation coefficient using SPSS software.-The data revealed that nearly all of the children [96.8%] consumed snacks between the main meals.-No relationship was found between type of diet and either oral hygiene or gingival status.-The amount of dairy products, fruits, vegetables and snacks taken didn't affect oral hygiene and gingival status.-There was no relationship between the time of snacks and sweets consumption and oral hygiene and gingival status. Poor oral hygiene can lead to periodontal diseases. The effect of diet on dental caries is obvious, however its effect on oral hygiene and gingival status is not completely understood. In this study no relationship was detected between diet and oral or gingival hygiene stata

Influence of free radicals on cardiovascular risk due to occupational exposure to mercury

This study was designed to investigate the relation between occupational exposure to mercury and cardiovascular risk, as well as free radicals. The study subjects included 30 male workers exposed to mercury from a fluorescent lamp plant in Alexandria after exclusion of 12 workers with conditions that may bias the results. A matched control group of 20 male subjects were selected from a food industrial plant. The participants were subjected to interview, clinical examination, electrocardiograph and R-R deep breathing variability test as a measure of cardiac autonomic function. Spot urine and venous blood samples were collected to measure mercury levels. Free radicals related markers were measured in serum namely lipid peroxide, superoxide dismutase [SOD] activity, catalase activity and glutathione S-transferase. Results showed significant longer electrocardiographic Q-T[c] interval, which is corrected to heart rate, in exposed workers than in controls [p=0.002]. The R-R deep breathing variability indices were significantly increased among exposed workers in comparison to controls [maximal variation [MV] ratio, p=0.024 and MV rate, p=0.019]. The mercury levels in both urine and blood of exposed workers were significantly higher than controls [p<0.0001], with mean levels exceeding the permissible limits. Free radicals related markers revealed significant higher level of lipid peroxide, as well as significant lower levels of SOD activity, catalase activity and glutathione S-transferase among exposed workers than among controls [p<0.0001 for all]. Independent relations were observed between Q-T[c] and lipid peroxide, and between MV rate and SOD and catalase activities among exposed workers after adjustment for the confounders by multivariate regression analyses. These findings may suspect a cardiac autonomic dysfunction probably related to free radicals in mercury exposed workers. Also, it may through light on some preventive implications