Pharmaceutical Sciences
Volume:17 Issue: 2, 2011

Chrozophora tinctoria(Euphorbiacea)is an annual which is endemic to Egypt, Japan and Iran.Methanolic extract of C. tinctoria inhibits the carcinogenic potential of 7, 12- dimethylbenz (a) anthracene(DMBA).This is attributed to antioxidant profile of this plant. Effects of paraquat on the lung are believed to be through oxidative stress. This study aimed at evaluating the inhibitory effect of Chrozophora tinctoria (methanolic extract) on paraquat-induced oxidative stress in mice lung tissue. Eight groups including 8 male Swiss mice were randomly assigned to receive the following drug regimens for 15 days:Paraquat was injected as singledose on the last day of the study.Groups including paraquat were: Group 1)Normal saline, group 2)normal saline and paraquat (100 mg/kg), group 3) C.tinctoria(only), group 4)C.tinctoria and paraquat (100 mg/kg), group 5) vitamin E (8 mg/kg), group 6)vitamin E (8 mg/kg) and C.tinctoria, group 7) vitamin E (8 mg/kg) and paraquat (100 mg/kg), group 8) vitamin E (8 mg/kg) and C.tinctoria and paraquat (100 mg/kg). Severity of wounds and dehiscence of bronchial mucosa and hemorrhage, were significantly (p<0.01)lower in groups receiving vitamin E,methanolic extract of C. tinctoriaor or both before paraquat intoxication comparing with mice with no prophylaxis. According to our results, methanolic extract of C. tinctoria is effective against oxidative stress in lungs due to paraquat intoxication.

Effective formulation of a stable solid dosage form depends on the proper selection of its excipients.The aim of this project is to optimize the flowability of Divalproex sodium powder (which has a waxy nature and poor flowability) using the central composite design. To this end, different excipients were used to improve the flowability of the powder.

The formulation design was carried out using central composite design with different excipient- drug ratios. The flow rate of the formlations were determined by flow meter machine and analyzed using Minitab software and then used for evaluation of the model. The suitable formulations were selected by this software in the aspect of flowability.

The results indicates that different amounts of excipients can cause different powder flowability characteristics. Adsorption of aerosil to powder surface as a glident,up to 2.75 gram improves its flowability, however in higher concentrations the reverse effect in powder flow is observed.Moreover lactose and Avicel in amounts of 2.5 and 7.5 g in Divalproex sodium tablet formulation respectively result in an accepted flowability.

It can be concluded that using central composite design is a shortcut method to design suitable formulations of divalproex sodium with appropriate flowability.

The objective of present study is to evaluate effect of the different parameters on physicochimical properties and viability of Lactobacillus acidophilus in Alginate-Poly l lysine-Alginate beads. Alginate beads with different concentrations of Alginate were prepared using extrusion method. Poly-l-lysine and Algiante as second and third coats were incorporated on the surface of Alginate beads using immersion technique.The morphological charactristics and the integrity of the prepared beads were investigated using lights microscope and SEM. Bacterial loading was obtained by camparison of bacterial counts in the Alginate gelant and prepared beads.The viability of L. acidophilus with and without coat after exposure to SGJ (pH of 1.5 and 2) before and after lyophilization were investigated. Growth preperties of the beads were also investigated by bacterial counting after exposure to simulated intestinal juice (SIJ) (pH=6.8). Optimum conditions for preparation of circular beads with high integrity and loading (98.7%) were achieved. Survival petcentages after 3hours exposure to simulated gastric juice (SGJ) with pH of 1.5 and 2 were 72 and 79 % respectively in camparison with no surviaval in uncoated bacteria. A good growth of bacteria from the beads in SIJ (pH=6.8) was observed with more than 2.5 (log cfu/g) increase during 24 hours. Lyophylized beads showed suitable viability after 3hours exposure to SGJ (69%),followed by a good growth in SIJ (pH=6.8). Preparation of beads of Lactobacillus acidophilus with alginate-poly l lysine-alginate can effeciently protect the bacteria from harsh conditions of GI tract.

This study evaluates the effect of granulating liquid in production of ibuprofen, Eudragit RL and Avicel pellets. Pellets containing ibuprofen (30, 40 and 60%), Eudragit RL (48, 38 or 18% respectively), Avicel (20%) and PVP K30 (2%) were prepared by extrusion spheronisation using water or water/ethanol mixture. The physicomechanical properties (pellet shape, size distribution, crushing strength, elastic modulus) and drug release were examined. The pellets were stored at 60 C for 24 hour (cured) and the effect of curing on mechanical properties and drug release was investigated. The extrudability of the wetted mass decreased with addition of ethanol. The pellet shape changed from spherical to irregular and the yield of pellets decreased with increase in ethanol concentration. The size distribution for pellets shifted toward smaller particle size. Pellets showed different behavior under the mechanical test depending on the ethanol concentration in granulating liquid and percent of drug in formulation. The rate of drug release decreased with increase in ethanol concentration in granulating liquid. For those pellets with brittle behavior, curing changed the behavior of pellet to plastic deformation. Elastic modulus of all formulations decreased after curing. Besides curing decreased drug release rate. Interestingly the effect of curing on mechanical and release behavior of pellets decreased with increase in concentration of ethanol in granulating liquid. The results revealed that addition of ethanol to granulating liquid resulted in production of ibuprofen and Eudragit RL pellets with different properties from those prepared using water alone.

The purpose of this study was synthesis of a novel smart copolymer and evaluation of its physicochemical characteristics as a suitable nano-carrier for ophthalmic drug delivery of anti-inflammatory drugs. Polymeric micelles were prepared by free radical copolymerization of N- isopropylacrylamide (NIPAAM), vinyl pyrrolidone (VP), and acrylic acid (AA) as [Poly (NIPAAM-AA-VP)] copolymer and Nisopropylacrylamide-acrylic acid-hydroxyethyl methacrylate as [Poly (NIPAAM-AA-HEM)] in 1, 4-dioxane under N2 atmosphere. In this study triethyleneglycol dimethacrylate (TEGDMA) applied as cross-linking agents. The chemical structures of cross-linked copolymers were confirmed by FT-IR and 1H- NMR spectroscopies. The PSA data represented that the particles had mean size under 500nm. The maximum swelling ratio of hydrogel occurred at 10 min at 37°C and pH 1.0 and at 125 min at 20 °C and pH 1.0. For all formulations, release rate had direct relationship with drug-polymer ratios. In this study dexamethasone and indomethacin was loaded as two model anti-inflammatory medicines in copolymeric structures. The prepared nanoparticles were stable in an aqueous solution and maintained their physicochemical characteristics such as particle size and drug loading content during seven days of storage. Evaluation of physicochemical properties of novel polymeric system showed this system not only was suitable for ocular drug delivery but also could be used as a delayed release system for longer duration of anti-inflammatory effect.

Design of experiments is frequently used to study chemical systems. If enzymatic reactions, as a chemical system, can be modeled using these methods, it will be possible to research with lower prices. Xanthine oxidase and xanthine were selected as enzyme and substrate, consequetively. Initial rate (V) of oxidation of xanthine was studied. Several experiments were designed using central composite design (CCD) method. Three parameters, temperature (T), pH and concentration of substrate, were selected and studied in this research. The reaction was started by adding the enzyme. Absorbance was recorded at 286 nm in different time then initial rate was calculated. Relation between response (initial rate) and selected parameters was studied and suitable mathematical equation was extracted and related response surfaces were plotted. The extracted equation was validated using some tests and other different experiments. CCD is one of the experimental methods that was used to study the oxidation reaction rate of xanthine as a function of T, pH and substrate concentration.These results show that the enzyme parameters can be predicted using extracted mathematical equation.

Cefuroxime axetil is a broad-spectrum second- generation cephalosporin which has activity against gram-positive and gram-negative microorganisms. The aim of the present study is designing and formulation of cefuroxime axetil tablets (250 mg) using direct compressiontechnique which is nowadays considered as a cost effective and simple method of tablet manufacturing. In order to obtain the optimized products, different formulations were designed using Cefuroxime axetil and 6 different excipients (lactose, avicel, aerosol, PVP,croscarmellose sodium (Ac-Di-Sol) and Magnesium stearate). After measuring the powder flow rate and hardness of formulation, five formulations were selected for dissolution test. All the selected formulations having accepted flow and hardness, released more than 60% drug in 30 minutes. It is concluded that using appropriate statistical methods and direct compression, suitable formulations of Cefuroxime axetil could be reached.