فهرست مطالب

Research in Pharmaceutical Sciences
Volume:5 Issue: 1, Apr 2010

  • تاریخ انتشار: 1389/10/11
  • تعداد عناوین: 8
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  • V. Hajhashemi, G. Vaseghi, M. Pourfarzam, A. Abdollahi Pages 1-8
    Free radicals are produced continuously in the cells as part of normal cellular function, however excess production might play a role in pathophysiology of many disease conditions, including cancer, Alzheimer's disease, atherosclerosis and some of the drug-induced toxicity. Many basic research studies and observational epidemiologic studies in human suggest that antioxidants can prevent oxidative damage. However, this is still a controversial issue because the results of clinical trials have been inconsistent. This article provides a brief overview of some of the diseases which are associated with free radicals, then discusses the roles of some of dietary antioxidant supplements in disease prevention, with particular reference to the findings of latest clinical trials.
  • M. Vosooghi, S. Rajabalian, M. Sorkhi, M. Badinloo, M. Nakhjiri, As Negahbani, A. Asadipour, M. Mahdavi, A. Shafiee, A. Foroumadi Pages 9-14
    A series of 2-amino-4-aryl-3-cyano-7-(dimethylamino)-4H-chromenes was synthesized by condensation of 3-(dimethylamino)phenol, an aromatic aldehyde and malonitrile in ethanol containing piperidine. The assignments of the structure of all synthesized compounds were based on spectral data (IR, Mass and 1H NMR). The cytotoxic activities of the synthesized compounds against six human tumor cell lines were determined by MTT assay. Several compounds showed significant cytotoxic activity.
  • H. Mir Mohammad Sadeghi, R. Rajaei, F. Moazen, M. Rabbani, A. Jafarian-Dehkordi Pages 15-19
    Taq DNA polymerase is widely used in laboratories and for this reason many investigators have focused their attention on understanding the role of various regions and amino acids in this enzyme. O-helix is a part of taq polymerase suggested to play an important role in the enzyme fidelity. The influence of Asn666 in this helix on the enzyme function has never been investigated, and therefore by using nested PCR, a portion of taq DNA polymerase gene containing Asn666Glu mutation was amplified. This DNA was digested with Eco RI restriction enzyme to confirm the presence of Asn666Glu mutation. After digesting this product and the wild type taq-pET-15b plasmid with NheI and BamHI restriction enzymes, they were ligated and used for the transformation of E. coli DH5α competent cells. The obtained colonies were screened for the presence of the mutated taq polymerase gene using EcoRI, NdeI and BamHI restriction enzymes. In conclusion, with the use of the obtained recombinant plasmid it is possible to study the role of this amino acid on taq DNA polymerase function.
  • Bs Fazly Bazzaz, M. Iranshahi, M. Naderinasab, S. Hajian, Z. Sabeti, E. Masumi Pages 21-28
    Galbanic acid, a sesquiterpene coumarin from Ferula szowitsiana, and conferol, another sesquiterpene coumarin from F. badrakema, were evaluated for their effects on the reversal of multi-drug resistance in clinical isolates of Staphylococcus aureus and Escherichia coli, respectively. Neither galbanic acid (up to 1000 μg/ml) nor conferol (up to 400 μg/ml) by itself shows any antibacterial activities against tested strains. The minimum inhibitory concentrations (MICs) of ciprofloxacin and tetracycline were determined using macrodilution technique in the presence and absence of sub-inhibitory concentrations of galbanic acid (31.25-1000 μg/ml) or conferol (50-400 μg/ml), however they caused no change in MICs of the antibiotics. Galbanic acid did not show any inhibitory effect on efflux phenomenon of E. coli. This can be related to the outer membrane of gram-negative bacteria which is impermeable to lipophilic compounds or another mechanism rather than efflux responsible for resistance in tested E. coli strains. An inhibitory effect of conferol on the efflux was compared with verapamil as a positive control. Because efflux is the only known mechanism of resistance to ethidium bromide (model efflux substrate) and verapamil reduced MIC of ethidium bromide, efflux mechanism can be considered as one of the resistance mechanisms in tested S. aureus strains. Conferol, however, did not enhance the antibiotic efficacy mediated by inhibiting efflux pumps in bacteria.
  • M. Jelvehgari, M. Maghsoodi, H. Nemati Pages 29-39
    The objective of the present investigation was to design a sustained release floating microcapsules of theophylline using two polymers of different permeability characteristics; Eudragit RL 100 (Eu RL) and cellulose acetate butyrate (CAB) using the oil-in-oil emulsion solvent evaporation method. Polymers were used separately and in combination to prepare different microcapsules. The effect of drug-polymer interaction was studied for each of the polymers and for their combination. Encapsulation efficiency, the yield, particle size, floating capability, morphology of microspheres, powder X-ray diffraction analysis (XRD), and differential scanning calorimetry (DSC) were evaluated. The in vitro release studies were performed in PH 1.2 and 7.4. The optimized drug to polymer ratios was found to be 4:1 (F2) and 0.75:1 (F'2) with Eu RL and CAB, respectively. The best drug to polymer ratio in mix formulation was 4:1:1 (theophylline: Eu RL: CAB ratio). Production yield, loading efficiencies, and particle size of F2 and F'2 were found to be 59.14% and 45.39%, 73.93% and 95.87%, 372 and 273 micron, respectively. Microsphere prepared with CAB showed the best floating ability (80.3 ± 4.02% buoyancy) in 0.1 M HCl for over 12 h. The XRD and DSC showed that theophylline in the drug loaded microspheres was stable and in crystaline form. Microparticles prepared using blend of Eu RL and CAB polymers indicated more sustained pattern than the commercial tablet (P<0.05). Drug loaded floating microballoons prepared of combination of Eu RL and CAB with 1:1 ratio were found to be a suitable delivery system for sustained release delivery of theophylline which contained lower amount of polymer contents in the microspheres.
  • S. V Tembhurne_D. M Sakarkar Pages 41-47
    The aim of the present study was to evaluate the effect of ethanolic extract of Murraya koenigii leaves (MKL) on blood glucose level and in prevention or management of diabetic neuropathy. In the present study the diabetic neuropathy was developed 9 weeks after single injection of streptozotocin (STZ, 70 mg/kg i.v.) in rat. The treatment with MKL (300 and 500 mg/kg p.o.) was started after stabilization of blood glucose level (13 days after STZ) and evaluated for determination of glycemic level, glycated haemoglobin, grip strength, pain sensitivity and threshold. The result showed that the treatment with MKL possessed hypoglycemic effect in diabetic treated animals. The results also indicated that the decreases in the grip strength in diabetic animals represented the induction of neuropathy 9 weeks after STZ treatment. Prior treatments with MKL increased the grip strength of diabetic rats. The results of pain sensitivity indicated the loss of pain perception in diabetic animals because of nerve damage. While prior treatment with MKL upto 9 week in diabetic animals resulted in the increase in the licking time and withdrawal latency in hot plate and tail flick tests, respectively, which indicates the presence of pain perception and prevention of nerve damage due to protective effect of MKL in progression of diabetic neuropathic pain. Therefore, the present study concludes that the chronic treatment with MKL significantly decreased the glycemic level as well as it protected the animals against development of diabetic neuropathy.
  • A. Sharma_C. P Jain Pages 49-56
    Solid dispersions in water-soluble carriers have attracted considerable interest as a means of improving the dissolution rate, and hence possibly bioavailability, of a range of hydrophobic drugs. The poor solubility of carvedilol leads to poor dissolution and hence variation in bioavailability. The purpose of the present investigation was to increase the solubility and dissolution rate of carvedilol for enhancement of oral bioavailability. In the present investigation solid dispersions with PVP K30 were prepared by solvent evaporation method. The physical mixture and solid dispersion(s) were characterized for drug-carrier interaction, drug content, solubility and dissolution rate. The solubility of drug increased with increasing polymer concentration. The dissolution rate was substantially improved for carvedilol from its solid dispersion compared with pure drug and physical mixture. As indicated from X-ray diffraction pattern and DSC thermograms carvedilol was in the amorphous form, which confirmed the better dissolution rate of solid dispersions. The solid dispersion was stable under accelerated storage conditions. The solid dispersion technique with PVP K30 as a carrier provides a promising way to enhance the solubility and dissolution rate of carvedilol.
  • A. R Guru Prasad_Vs Rao Pages 57-63
    Polarographic methods have been developed for the determination of two cephalosporins namely cefotaxime (CTX) and ceftriaxone (CTR) in pharmaceutical formulations. Well defined peaks at potentials –1.432 V vs. SCE for CTX and –1.627 V vs. SCE for CTR were obtained in the presence of tungsten (VI). The method has been successfully applied for the determination of above mentioned cephalosporins in commercial dosage forms. The salient features of this investigation are presented in this communication.