Iranian Journal of Pharmaceutical Sciences

Controlled release swellable tablets of phenobarbital were prepared by a simple direct compression process using hydroxypropyl methylcellulose (HPMC) as the matrix former. The effects of the viscosity grades of HPMC and HPMC/lactose ratio and ethylcellulose (EC)/sodium carboxymethylcellulose (NaCMC) and their concentrations on the release behavior of phenobarbital from HPMC matrices were investigated. In order to determine the mode of release, the data were analyzed based on the equation Q= K tn. Higher drug release rate was found for formulations with lower HPMC/lactose ratios and lower HPMC viscosity grades. The viscosity of HPMC polymer has a large influence on the erosion rate of matrix tablet. Use oflow viscosity grade of HPMC polymer is desired for drugs that are poorly water soluble such as phenobarbital since the erosion rate of tablet matrix is the controlling factor for drug release. As the proportion of EC or NaCMC in admixture with HPMC increased, the release rates gradually increased. It is also observed that the amount of HPMC played a dominant role, affecting the drug release in binary mixtures.Invitrorelease studies demonstrated that use of an appropriate blend of HPMC and EC or NaCMC enables to better control of drug release profiles and approach to zero order kinetic.

Paclitaxel is a highly effective anticancer agent. It is active against a broad range of cancers that are generally considered refractory to conventional chemotherapy.Paclitaxel induces a peripheral neuropathy (PN) that is characterized by sensory symptoms such as numbness and paresthesia in a glove and stocking distribution.PN may be severe and dose limiting at initial doses above 275 mg/m2. Our purpose was to evaluate the incidence, severity, dose dependency, and reversibility of paclitaxel-induced neuropathy. We studied 45 patients with breast cancer, treated with Paclitaxel (240, 270, 300 mg/m2) in an average of 4 cycles of treatment.Paclitaxel was administered by a 3 h intravenous infusion every 3 weeks in all patients.We used National Cancer Institute-Common Toxicity Criteria (NCI-CTC) to evaluate peripheral neuropathy. The cumulative dose of paclitaxel in each patient was also measured. The severity of symptoms was graded. Incidence and reversibility of neuropathy was measured in an interview with the patient. Paresthesias appeared in 39 (86.6%) patients after an average cumulative dose of 394 mg/m2.In most patients, PN was seen after the first or second dose (68%) of paclitaxel and then stabilized in 36%, improved in 36%, resolved completely in 24% and progressed in 4%. There was no need to discontinue Paclitaxel in any of the patients due to PN.In view of our experience in the present study, we found that Paclitaxel-induced neuropathy is a dose-dependent phenomenon, and most of the symptoms occurred after the first or second phase of treatment.

Production and characterization of soft cross-linked gelatin sponge by using glutaraldehyde for blood hemostasis application, is the goal of this study.Biodegradable hydrogels were prepared through crosslinking of gelatin with glutaraldehyde followed by freeze drying. The effects of gelatin concentration, amount of crosslink agent and freeze drying temperature on mechanical properties andelasticity, stability and degradation rate, swelling and water absorption ability,hemostatic effect and cytotoxicity were investigated. As the freezing temperature was lowered, the density of freeze-dried sponges increased. Density of samples is strongly dependent on the freezing temperature before freeze-drying. The addition of GTAas cross linker agent changed density very slightly, but no direct relationship between the amount of cross linker and the density was observed. Gelatin sponges prepared by freeze-drying after freezing at -10 and -25 ºC had large pores. Network structure of heterogeneous pores. The rate of weight loss decreased with increasing degree of crosslinking of the samples, and the higher degree of cross-linking in gelatin sponges causes more resistance to degradation in PBS solution. Gelatin concentration increase had very sharp effect on raising the compression module, and freezing temperature changed inner structure of sponges and can affect mechanical behavior.

Synthetic hydroxyapatite (HA) is the most helpful because of its similarity to natural bone in both crystalline structure and chemical composition. Recently,fluoridated hydroxyapatite (FHA) has been developed in dental and orthopedic application because it has lower solubility than pure HA, while maintaining the comparable bioactivity and biocompatibility. The aim of this study was to synthesis and characterizes FHAnanopowder via mechanochemical activation method. Also the effect of milling time and rotation speed on its properties was investigated.Calcium hydroxide, phosphorous oxide and calcium fluoride powder were used for synthesis of FHA. The math ratio of balls to reactant was 30. Mechanochemical reaction was performed in the planetary ball mill at two rotating speed 300 and 250rpm. Zirconia ball and zirconia vial were used to perform the mechanochemicalprocess. X-ray Diffraction, FTIR spectroscopy and Scanning Electron Microscopy were utilized to characterize FHAnanopowder. The results showed that the synthesis of FHAafter 6 h ball milling at 300 rpm or 10 h milling at 250 rpm was complet.

The in vitrodissolution of plasma-sprayed hydroxyapatite (PHA) coatings with different characteristics, produced by various spraying conditions, in a Tris-buffered solution at pH 7.4 was experimentally studied through the measurement of calcium ions release with Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES), and then modeled. Three coating characteristics, the crystallinity, the degree of recrystallization and the porosity were evaluated. The analytical modeling revealed that the calcium dissolution process was composed of two stages. The first stage was found to be both surface and diffusion controlled. The second stage was an exactly diffusion controlled dissolution. In the first stage, the solubility and dissolution rate of the PHAcoatings were mainly increased with decreasing the crystallinity, and partly with increasing the degree of recrystallization and the porosity. The degree of recrystallization was found to control the dissolution rate of the PHAcoatings in the second stage. It was suggested that the promotion of a rapid integration of implant to bone can be achieved by the optimization of the degree of crystallinity and recrystallization at coating surface.

The muscle-like technology would be of enormous advantages for biomedical applications such as medical implants and human assist devices. Ionic polymer metal composites (IPMCs) are one kind of biomimetic actuators. An ionic polymer metal composite composed from an ionomer with high ion exchange capacity that packed between two thin metal layers. In the present study we focused on the preparation of a novel alternative polymeric ionomer to be used as artificial muscles. Sulfonated poly(ether ether ketone) (PEEK) have been synthesized as a new class of ionomeric membrane materials. PEEK was sulfonated at various degrees with sulfuric acid and N,N-Dimethylacetamide as a solvent. Fourier transfer infrared spectroscopy confirmed the quality of substitution reaction. Sulfonated samples showed O-H vibration at 3490 and S=O peaks at 1085 and 1100-1300 cm-1. By increasing degree of sulfonation to 80%, ion exchange capacity, water uptake and the number of water molecules per the fixed sulfone groups (λ) were increased to about 2.4 meq.g-1, 75% and 19, respectively. After calculating the optimum degree of sulfonation, the applications of these ionomers as actuators are studied. Rigid microstructure of PEEK backbone causes to slow displacement. However, this inflexible backbone showed the acceptable tip force during its actuation. These IPMC are easy to prepare and much less expensive than the commercial per-fluorinated membranes such as Nafion®. The results approve the utilization of sulfonated aromatic for artificial muscles applications as novel strong muscles with low flexibility.

Anti-inflammatory activity has been reported for a few of antidepressant drugs and in contrary sertraline has potentiated inflammation. In this study, anti-inflammatory effect of a collection of antidepressant drugs belonging to different classes was evaluated to help a rational selection of these drugs in disease conditions such as association of depression or anxiety with inflammatory diseases such as rheumatoid arthritis. Male Wistar rats weighing 160-200 g were used. Anti-inflammatory activity was assessed using carrageenan-induced paw edema test.Amitriptyline, nortriptyline, desipramine, trimipramine, fluvoxamine (37.5 and 75mg/kg), fluoxetine (30 and 60 mg/kg), citalopram (10 and 40 mg/kg), doxepin and maprotiline (25 and 50 mg/kg) were administered s.c. 30 min. prior to subplantar injection of 100 µl carrageenan suspension (1% w/v). Difference of paw volume measured just before and 4 h after carrageenan injection was considered as an index of inflammation. Except nortriptyline and citalopram, all tested drugs showed anti-inflammatory activity. It seems that the anti-inflammatory effect is not correlated with inhibition of norepinephrine and/or serotonin reuptake transporters and further studies are needed to clarify the exact mechanism of their anti-inflammatory action.

Tribulus terrestrisL. var. orientalis(Kerner) G. Beck is widely used in the traditional medicine of many countries. Several flavonoides are identified from the plant material. Aerial parts which collected from northeast of Iran are used in this study. Three flavonoid glycosides were isolated and characterized. The flovonoids were found to be based on quercetin and kaempferol. Flavonoid glycosides whichs eparated were consisted of quercetin 3-O-glycoside, quercetin 3-O-rutinoside and kaempferol 3-O-glycoside. The latest one was a new for the plant.