فهرست مطالب

Research in Pharmaceutical Sciences
Volume:3 Issue: 2, Oct 2008

  • تاریخ انتشار: 1387/07/01
  • تعداد عناوین: 8
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  • Vt Thakkar, Pa Shah, Tg Soni, My Parmar, Mc Gohel, Tr Gandhi Page 1
    The objective of this work was to develop and evaluate the levofloxacin hemihydrate floating formulations (F1-F9). Selection of optimized batch was done by model dependent approach and novel mathematical approach. F1-F9 batches were prepared by direct compression method using Gelucire 43/01 (hydrophobic) and ydroxypropylmethylcellulose (hydrophilic) polymer in different ratios. The floating tablets were evaluated for uniformity of weight, hardness, friability, drug content, in vitro buoyancy and in vitro release studies. Various models were used to estimate kinetics of drug release. The criteria for selecting the most appropriate model were based on the goodness-of-fit test and lowest sum of square residual and Fischer’s ratio. In vitro release study reveals that the release rate of drug was decreased by increasing the proportion of Gelucire 43/01, 5 to 40%. The release rate of levofloxacin hemihydrates from matrices was mainly controlled by the hydrophilic and hydrophobic polymer ratio. Matrix tablet containing 25% HPMC K4M and 15% Gelucire 43/01 (F4 batch) showed a release as target profile. Optimal batch (F4) was selected by regression analysis which followed Higuchi kinetic. Novel mathematical approach was applied to determine the deviation in area under the curve (AUC) between predicated and observed dissolution data which found to be lowest in optimal batch. The drug release was found to be function of ratio of hydrophobic to hydrophilic matrixing agents.
  • H. Sadraei, G. Asghari, M. Khazae Page 9
    Hydroalcoholic extract of Pycnocycla spinosa was shown to have spasmolytic action in vitro and antidiarrhoeal effect in vivo. The hydroalcoholic extract of P. spinosa is composed of alkaloid, flavonoid and saponin components. Alkaloid fraction of P. spinosa contains the most active constituents. Therefore, the aim of this research was to separate different fractions of alkaloid extract of P. spinosa and screen for their spasmolytic activity on rat isolated ileum. Alkaloid fraction of P. spinosa was separated by fractional liberation technique. Four fractions were separated from the alkaloid rich fraction using thin layer chromatography. All 4 separated fractions inhibited the spasmolytic response to 80 mM KCl in a concentration-dependent manner. Two of the separated fractions also inhibited the response to ACh and 5-HT. This study showed the relationship between antispasmodic actions of different components presented in 4 fractions obtained from alkaloid extract of P. spinosa.
  • M. Minaiyan, A. Ghannadi, P. Mahzouni, M. Nabi, Meibodi Page 15
    Spasmolytic, antioxidant, anti-inflammatory and immuno-modulatory properties of ginger (rhizome of Zingiber officinale Roscoe) suggest that it may has beneficial effects on inflammatory bowel diseases. In the present study, the effect of this herbal extract on a model of acute colitis was evaluated. Ginger hydroalcoholic extract with doses of 150, 350, 700 mg/kg, prednisolone (2 mg/kg), or vehicle were administered orally to groups of male Wistar rats (n=6) for 5 days. Other four groups received two doses of vehicle, extract (350, 700 mg/kg), or hydrocortisone acetate enema (10 mg/kg) rectally, 15 and 2 h prior to ulcer induction (2 ml of acetic acid 4% was instilled via the anus). All rats were sacrificed 24 h later and the tissue injuries were assessed macroscopically and pathologically. Extracts with all doses used were effective to reduce colon weight/length ratio similar to the reference drugs (corticosteroids). Higher oral doses of extracts (350 and 700 mg/kg) were effective to reduce ulcer severity, area and index as well as mucosal inflammation severity, extent and total colitis index compared to controls. Rectally administered extract, only at high dose (700 mg/kg) was effective to reduce ulcer index and total colitis index. It is concluded that ginger hydroalcoholic extract was effective to protect against experimental colitis, and the efficacy was greater when higher doses of extract were administered orally and in a prolonged period.
  • T. Akbarzadeh, S. Motagian, A. Fallah Tafti, A. Shafiee, Ar Shahverdi Page 23
    Bacterial resistance is a major drawback in chemotherapy of infectious diseases. In this investigation a new series of 3,5-diarylamide dihydropyridines containing 2-benzylsulfonylimidazol at 4 position have been synthesized and studied for their enhancing effect on the antibacterial activities of different penicillins against a resistant clinical isolate of S. aureus using disc diffusion method. During preliminary screening, compound 6d showed the most enhancing effect on the antibacterial activity of amoxicillin against the test strain and the combination effect of this compound has been further studied with penicillin G and piperacillin against Staphylococcus aureus. The result of this evaluation showed that the antibacterial activities of penicillin G and piperacillin can be also enhanced by compound 6d suggesting a possible utilization of this compound in combination therapy against penicillin resistant S. aureus.
  • M. Tabbakhian, A. Sharifian, Ma Shatalebi Page 31
    Preparation of tretinoin-containing microspheres with the aim of reducing undesirable skin reactions towards trans retinoic acid (TRA) and thus, improving patient compliance is of particular interest. These microspheres have to be smaller than 30 mm to avoid causing gritty feel when applying on the skin, and slow the release of drug to minimize its skin side effects. Following preliminary evaluations on process conditions for preparation of microspheres by an emulsification-solvent extraction technique, a 23 full factorial design was employed to investigate the influence of various formulation variables including cellulose acetate (CA) concentration, polyvinyl alcohol (PVA) concentration and TRA to polymer weight ratio on physical properties and release behavior of microspheres. The particle size of microspheres increased with increasing CA concentration and TRA to polymer weight ratio, but was not much influenced by PVA concentration. The drug encapsulation efficiency increased in microspheres made at higher PVA concentration or with lower CA and TRA concentrations. Examining release data by Korsmeyer-Peppas equation indicated that the Fickian mechanism was basically involved in the drug release from all formulations. In general, a slower drug release rate (i.e. greater mean dissolution time) and smaller dissolution efficiency values were obtained where lower PVA concentration, higher CA concentration or lower drug to polymer weight ratio were used to prepare microspheres. Our results indicated that TRA-containing microspheres of suitable drug release profile and optimal particle size can be prepared by a simple emulsification-solvent extraction technique, provided that the process conditions are appropriately adopted and that polymer, emulsifier and drug concentrations are properly selected.
  • M. Ashengroph, I. Nahvi, H. Zarkesh, Esfahani Page 41
    Vanillin is undoubtedly one of the most popular and widely used flavoring agents in the world. Natural vanillin is extracted from vanilla beans and is relatively expensive. Moreover, the consumer demand for natural vanillin highly exceeds the amount of vanillin extracted by plant sources. This had led to the investigation of alternative routes for its production such as microbial bioconversion. In this study, a novel strain bacterium capable of converting isoeugenol to vanillin was isolated by conventional enrichment process from soils of spicy plants farms. On the basis of morphological and physiochemical characteristics, the isolate was identified as Pseudomonas sp. strain ISPC2. Vanillin formation was analyzed by spectrophotometery with thiobarbituric acid reagent and evaluated accurately by gas chromatography. Using 10 g/l of isoeugenol as substrate in 25 ml reaction solution at 30 °C and 150 rpm, vanillin reached a maximum concentration of 1.15 g/l after 96 h reaction, corresponding to a molar yield of 12.4%. This strain showed potential to be a good candidate for biotechnological production of vanillin from isoeugenol. Further studies for standardization and optimization for higher yield of vanillin production needs to be investigated.
  • M. Panjehpour, M. Bayesteh Page 49
    Cadmium has been known to be harmful to human health, mainly via contaminated drinking water, food supplies, tobacco and industrial pollutants. The aim of this study was to determine the ability of cadmium chloride (CdCl2) to cause cell death in the human lung carcinoma cell line (Calu-6). The cells were grown in RPMI-1640 medium supplemented with 10% FCS, penicillin/streptomycin (100 U/ml, 100 µg/ml) at 37 ºC in 5% CO2/95% air. The cells were plated in 96 multi-well plates. After 24 h, the medium was replaced with fresh medium containing different concentrations of CdCl2 and incubated for 48 and 72 h. MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) cell viability test was used to study the cytotoxic effects of Cd. Exposure of monolayers to different metal concentrations (1-1000 µM) in different times showed a significant decrease (P<0.05) in cell viability when compared with that of controls. In a dose-dependent manner, a significant cytotoxicity was observed at 200 µM for CdCl2 during 48 h and 1 µM during 72 h exposure. However the concentrations greater than 200 μM had no significant effect to accelerate the power of cytotoxicity. Thus, CdCl2 has this ability to induce cytotoxicity in the human lung carcinoma cell line in the lower micromolar concentrations. In conclusion, while high concentrations of Cd are harmful to human, lower concentrations induce a significant cytotoxicity in the cancer cells. This finding may introduce a new view on the mode of action and possible application of trace elements in the cancer treatment.
  • M. Amanlou, F. Nabati, H. Azizian, H. Farsam Page 55
    Tea is the second most commonly consumed beverage world wide. Tea (Camellia sinensis) is a naturally rich source of fluoride. The quantity of fluoride intake is important in optimizing its dental caries-preventive role. Intense concentration of fluoride in tea, can lead to excessive fluoride intake which may cause health problems in turn. The measurement of fluoride intake usually requires information on the fluoride concentration in food and beverages. The main objective of this study was to investigate the fluoride content of various commercial brands of tea bag available on the market in Iran. Furthermore, daily fluoride intake from these brands is assessed. The results of this study showed that among 15 brands of tea bag assessed in this study, NemoonehTM had the highest fluoride concentration (0.41 ± 0.01 mg/100 ml/3 min), whereas AhmadTM had the lowest level (0.10 ± 0.01 mg/100 ml/3 min). The average fluoride concentration was 0.23 ± 0.01 mg/100 ml/3 min. Thus, it seems that daily consumption of four cups of tea could provide up to 73% of recommended daily dose of fluoride in children 2-5 years old and up to 50% recommended daily dose for adults. It seems that existing tea bag in Iranian market contain proper amounts of fluoride and there is no toxicity with their regular consumption.