فهرست مطالب

Research in Pharmaceutical Sciences
Volume:7 Issue: 1, Feb 2012

  • تاریخ انتشار: 1390/09/13
  • تعداد عناوین: 8
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  • S. R Abtahi_H. Sadraei_M. Nematollahi_K. Karbalaie_F. Karamali_A. Salamian_H. Baharvand_M. H Nasr-Esfahani Pages 1-11
    Royan B1 stem cell can be differentiated to specialized cell types including cardiomyocytes. This developmental change is accompanied with expression of various K+ channel types. The aim of this study was to detect functional expression of K+ currents from stem cell stage and one week and two weeks after differentiation into cardiomyocyte. Mouse stem cell derived cardiomyocytes (ES-cardiomyocytes) were isolated to single cell suspension for K+current recording using whole cell patch-clamp technique. The predominant depolarizing current in ES-cardiomyocytes was a tetraethylammonium (TEA) (10 mM) sensitive current which was partially blocked by nifedipine (1 µM) and attenuated by increasing concentration of EGTA (10 mM) in the pipette solution. Pharmacology and electrophysiological properties of this oscillatory sustained current very well matched with characteristics of Ca2+ activated K+ current. In addition there was another kind of sustained outward K+ current which was resistance to TEA but was inhibited by 3,4-diaminopyridine. The characteristic features of this current indicate that this current was due to activation of delayed rectifier K+ channels. RT-PCR study also confirmed expression of these two types of K+ channels in ES-cardiomyocytes. Therefore, present study shows functional expression of two types of K+ ionic current in ES-cardiomyocytes.
  • M. Dixit_P. K Kulkarni Pages 13-21
    Piroxicam (PX), an anti-inflammatory drug, exhibits poor water solubility, dissolution and flow properties. Thus, the aim of the present study was to improve the solubility and dissolution rate of PX by freeze drying technique using dimethylformamide (DMF), chloroform and water as co-solvent system. The prepared crystals containing PX were evaluated for DMF and chloroform solvent residual by gas chromatography and solubility and in vitro dissolution. The prepared formulations were characterized by scanning electron microscopy, differential scanning calorimeter; X-ray diffraction and fourier transform infrared spectroscopy. Dissolution profile of the freeze dried crystals was compared with its recrystallized and pure samples. The samples were stored in stability chamber to investigate their physical stability. Solvent residual of DMF and chloroform was found to be within the toxic level. Freeze dried crystals exhibited decreased crystallinity and the solubility and dissolution of the PX crystals were significantly improved compared to its recrystallized and pure samples. In stability test, the release profile of the freeze dried crystals was almost unchanged as compared with the freshly prepared freeze dried crystals stored at 40°C and 75% relative humidity for 90 days. Hence, this technique can be used for formulation of tablets of PX by direct compression with directly compressible tablet excipients.
  • F. Hassanzadeh_M. Rahmani Khajouei_G. H Hakimelahi_E. Jafari_G. A Khodarahmi Pages 23-30
    Quinazolinones are interesting materials because of their valuable biological effects. In this study some new 2,3-disubstituted-4(3H)quinqzolinone derivatives were synthesized from anthranilic acid in six steps by introducing a new chiral center to the aliphatic side chain of the quinazolinone. In the last step, a single acylation on the hydrazine moiety afforded final compounds. The structures of compounds were confirmed by IR, 1HNMR and Mass spectra.
  • M. Jalali, D. Abedi, J. Varshosaz, M. Najjarzadeh, M. Mirlohi, N. Tavakoli Pages 31-35
    Freeze-drying is a common preservation technology in the pharmaceutical industry. Various studies have investigated the effect of different cryoprotectants on probiotics during freeze-drying. However, information on the effect of cryoprotectants on the stability of some Lactobacillus strains during freeze-drying seems scarce. Therefore, the aim of the present study was to establish production methods for preparation of oral capsule probiotics containing Lactobacillus paracasei subsp. tolerance and Lactobacillus delbrueckii subsp. Bulgaricus. It was also of interest to examine the effect of various formulations of cryoprotectant media containing skim milk, trehalose and sodium ascorbate on the survival rate of probiotic bacteria during freeze-drying at various storage temperatures. Without any cryoprotectant, few numbers of microorganisms survived. However, microorganisms tested maintained higher viability after freeze-drying in media containing at least one of the cryoprotectants. Use of skim milk in water resulted in an increased viability after lyophilization. Media with a combination of trehalose and skim milk maintained a higher percentage of live microorganisms, up to 82%. In general, bacteria retained a higher number of viable cells in capsules containing freeze-dried bacteria with sodium ascorbate after three months of storage. After this period, a marked decline was observed in all samples stored at 23°C compared to those stored at 4°C. The maximum survival rate (about 72-76%) was observed with media containing 6% skim milk, 8% trehalose and 4% sodium ascorbate.
  • V. Hajhashemi, L. Saghaei, A. Fassihi, H. Mojiri-Froshani Pages 37-42
    Derivatives of pyridine-4-one are iron chelators with various biological activities including antifungal, anti-malarial, antiviral, anti-inflammatory and analgesic activities. This study was aimed to evaluate the analgesic effect of four new derivatives of 3-hydroxy pyridine-4-one in animal models. Acetic acid-induced writhing and formalin tests were used to assess the analgesic activity in male mice (18-22 g). Compound A (2.5-10 mg/kg), B (100-400 mg/kg), C and D (50-200 mg/kg) were administered intraperitoenally. Indomethacin and morphine were used as reference analgesic drugs. All tested compounds showed significant analgesia in acetic acid-induced writhing and the second phase of formalin test. All compounds except compound B also had analgesic activity in the first phase of formalin test. Among the investigated compounds, compound A which showed analgesic activity at doses of 2.5-10 mg/kg considered as the most potent analgesic compound. Structurally compound A lacks polar moieties such as –OH or –COOH and is less polar than the others. Therefore it seems that it has a better penetration into lipophilic sites of action.
  • M. Tabbakhian_J. A Rogers Pages 43-50
    The interaction of drugs and polymers used to incorporate in or surface modify/coat the liposomes can affect the phase transition, fluidity and other physical properties as well as in vivo fate of vesicles. In this study, differential scanning calorimetry (DSC) was used to investigate changes in the temperature and the enthalpy of phase transition of liposomes of various electrical charges following interaction with carboxymethyl chitin (CM-chitin) as a hydrophilic polymer, cholesterol-derivatized mannan (CHM) as a hydrophilic polymer bearing a hydrophobic moiety, and insulin as a model peptide. The results indicated that insulin incorporation or polymers caused no significant change in the phase transition temperature (Tm) of liposomes. However, reduction in the enthalpy of the transition (DH°) following coating with CHM supports an anchoring mechanism to the bilayer by the polymer, whereas no change or little increase in the DH° after coating with carboxymethyl chitin suggests no significant interaction or electrostatic weak interactions of polymer with liposomes. The DSC data of liposome-polymer interaction may be suggestive of changes in membrane fluidity, drug release, and possibly the behavior of liposomes in biological milieu.
  • S. Dehshahri, S. Afsharypuor, G. Asghari, A. Mohagheghzadeh Pages 51-56
    Moringaceae, a monogeneric family in Capparales (glucosinolate-containing species), includes 14 species. One of them is Moringa peregrina (Forssk.) Fiori., a small tree, which grows in south east of Iran. Volatile constituents of seed coat and stem of M. peregrina were determined by GC and GC/MS. Moreover, extracts of seed and different cultured cells were analyzed by TLC and GC. Three volatile isothiocyanates including isopropyl isothiocyanate (4.2%), sec-butyl isothiocyanate (< 0.1%) and isobutyl isothiocyanate (92.9%) were found in the volatile oil of the stem, while only two volatile isothiocyanates namely isopropyl isothiocyanate (7.0%) and isobutyl isothiocyanate (51.5%) were determined in the seed coat of the tree. For the first time, the callus and suspension cultures of M. peregrina were initiated and established successfully on Murashige and Skoog medium, containing plant growth hormones. Different precursors and elicitors were fed to the cultures to induce glucosinolates production. This is the first report of in vitro culture production of M. peregrina. There was no production of volatile isothiocyanates in M. peregrina callus and suspension cultures with different treatments.
  • H. V Chavda Patel_C. N Patel Pages 57-64
    The objective of the present study was to design an oral controlled drug delivery system for sparingly soluble diclofenac sodium (DCL) using guar gum as triple-layer matrix tablets. Matrix tablet granules containing 30% (D1), 40% (D2) or 50% (D3) of guar gum were prepared by the conventional wet granulation technique. Matrix tablets of diclofenac sodium were prepared by compressing three layers one by one. Centre layer of sandwich like structure was incorporated with matrix granules containing DCL which was covered on either side by guar gum granule layers containing either 70, 80 or 87% of guar gum as release retardant layers. The tablets were evaluated for hardness, thickness, drug content, and drug release studies. To ascertain the kinetics of drug release, the dissolution profiles were fitted to various mathematical models. The in vitro drug release from proposed system was best explained by the Hopfenberg model indicating that the release of drug from tablets displayed heterogeneous erosion. D3G3, containing 87% of guar gum in guar gum layers and 50% of guar gum in DCL matrix granule layer was found to provide the release rate for prolonged period of time. The results clearly indicate that guar gum could be a potential hydrophilic carrier in the development of oral controlled drug delivery systems.