Advanced Pharmaceutical Bulletin
Volume:1 Issue: 2, Dec 2011

A multiparticular floating-pulsatile drug delivery system was developed for time and site specific drug release of piroxicam. A blend of floating and pulsatile principles of drug delivery system would have the advantage that a drug can be released in the upper GI tract after a definite time period. Hollow microspheres were prepared by the emulsion solvent diffusion method using Eudragit S as an enteric acrylic polymer with piroxicam at various polymer/drug ratios in a mixture of dichloromethane and ethanol. Developed formulations were evaluated for yield, encapsulation efficiency, particle size, shape, apparent density, buoyancy studies and dissolution studies. The obtained microballoons were spherical with no major surface irregularity and mean particle size ranging from 250 to 380 for different batches. Formulations show a slight amount of relaese ranging from 0.7 to 11% in acidic medium (SGF) with complete release of drug in simulated intestinal fluid (SIF) in less than 3 h. Encapsulation efficiency of different formulations varied from 90 to 98%. The optimum loading amount of drug in the particles was found to impart suitable floatable properties to the microballoons. With increasing polymer/drug ratio, buancy of the microballoons increases accompanied by simultaneous reduction of apparent particle density. A pulsatile release of piroxicam was demonstrated by a simple drug delivery system which could be useful in chronopharmacotherapy of rheumatoid arthritis.

Hyssopus officinalis (L) (Hyssop, Family: Lamiaceae), one of the endemic Iranian perennial herb with a long history of medicinal use, was studied to detect some biologically active chemical constituents of the plant. The flavonoids of the hydromethanolic extract of the aerial parts of Hyssopus officinalis (L.) were studied by VLC and crystalisation of the major compound in subsequent fractions. Furthermore, the composition of its essential oil, total phenolic content and antioxidant activities were studied by GC-MS, Folin–Ciocalteau and DPPH reagents respectively. Apigenin 7-O-β-D-glucuronide was isolated as the major flavonoid. All structural elucidation was performed by spectral means. A total of 20 compounds representing 99.97% of the oil have been identified. Myrtenylacetate, Camphor, Germacrene, Spathulenol were the main compounds The total phenol content of the n-butanol and ethylacetate extracts were determined spectrophotometrically according to the Folin–Ciocalteau procedure to be 246 mgGAE g-1 and 51 mgGAE g-1 in the aerial parts of Hyssopus officinalis. The antioxidant activities of apigenin 7-O-β-D-glucuronide, ethylacetate and n-butanol extracts were also determined by DPPH radical scavenging assay with IC50 values of 116×10_3, 103×10_3, 25×10_3 mg mL-1 respectively. The purified flavonoid showed weak radical scavenging activity (IC50 = 116×10_3mg mL_1). N-butanol extract, because of the highest content of total phenolic compounds (246 mgGAE100_1g) had the best antioxidant activity (IC50 = 25mg mL_1). On the whole, the findings of the study revealed that Hyssop possesses valuable antioxidant properties for culinary and possible medicinal use.

Context: Gentamicin is mainly used in severe infections caused by gram-negatives. However toxicity including nephrotoxicity and ototoxicity is one of the most important complications of its treatment. The production of free radicals seems to be involved in gentamicin toxicity mechanism. Taurine, a major intracellular free β-amino acid, is known to be an endogenous antioxidant. So potentially the co-therapy of taurine and gentamicin would reduce the adverse effects of the antibiotic. In this study, we wished to know the effect of taurine on the antibiotic capacity of gentamicin. strains of P. aeruginosa, E. coli, S. aureus and S. epidermidis were used as test organisms. Minimum inhibitory concentrations of gentamicin in the presence and absence of taurine at quantities from 40 to 2 mg/L were determined using macro-dilution method. MICs were determined in the various concentrations of taurine for bacterial indicators. The MIC values of gentamicin for P. aeruginosa, S. aureus and E. coli remained unchanged in the values of 2.5, 5 and 20 μg/ml respectively in the absence and presences of different concentrations of taurine. The bactericidal activity of gentamicin against S. epidermidis was increased by addition of taurine in the concentrations higher than 6 mg/L. According to our study the antibacterial activity of gentamicin against the indicator microorganisms were not interfere with taurine at selected concentrations. Further in vivo studies are needed to establish if a combination of gentamicin and taurine would have the same effect.

The occurrence of multi-antibiotic resistance among enterococci is a prevalent clinical problem worldwide and continues to get serious due to the lack of efficient therapeutic options by the time. In this regards, prokaryotic antimicrobial peptides with bactericidal or bacteriostatic activity which are directed against bacterial strains closely related to producer strains looks one of the promising alternative to conventional antibiotics. The antibiotic susceptibility pattern of 20 clinical isolates of enterococci was evaluated and subsequently the isolates were screened for antibacterial activity against three different indicator strains. The efficacy of potential bacteriocinogenic isolates were assayed against multi-antibiotic resistant Enterococcus spp. by comparative minimum inhibitory concentration (MIC). Antibiotic resistant pattern of enterococcal isolates demonstrated that multi-antibiotic resistant to conventional antibiotics were significantly high and the prevalent pattern of resistance was combination of gentamicin, streptomycin, chloramphenicol and vancomycin. In addition, the data from comparative MIC showed the noticeable activity of selected potential bacteriocinogenic strains against pathogenic enterococci. The present survey may address the potential applicability of antimicrobial peptides in alleviating the problems of antibiotic resistance.

Resveratrol a natural polyphenolic stilbene derivative has wide variety of biological activities. There is also a large body of evidence demonstrating positive effect of resveratrol in treatment of various metabolic complications including metabolic syndrome, obesity, diabetes and dyslipidemia in adults. The purpose of this study was to investigate anti-hyperglycemic and anti-dyslipidemic effects of resveratrol. We used 40 diabetic streptozotocin Wistar rats. Rats were randomly divided into 5 treatment groups (n=8 in each) including normal control, normal treated with resveratrol, diabetic control, diabetic treated with vanadium, diabetic treated with resveratrol. Resveratrol (25 mg/kgbw) and vanadate (0.2 mg/kgbw) was orally gavaged for 40 days and blood samples were directly collected from heart. Diabetic rats treated with resveratrol in comparison to control diabetic rats demonstrated a significant (p = 0.001) decline in serum glucose concentration, and high plasma concentrations of total cholesterol and LDL-c were reduced (p = 0.031, p = 0.004 respectively). Furthermore, body weight loss trend that observed in diabetic rats alleviated by resveratrol and vanadate. However triglyceride, VLDL-c and HDL-c levels did not changed significantly. In conclusion Resveratrol ameliorated dyslipidemia and hyperglycemia in diabetic rats. However further investigations in peculiar human studies are required.

The aim of the present study was minimizing the drug release in upper gastro intestinal tract and targeting to colon by using the principles of compression coat. Compression coated tablets of Ibuprofen were prepared by direct compression method using chitosan (300, 250, 200 & 175 mg). Tablets were evaluated for their physicochemical properties and in vitro drug release studies. In vitro drug release studies were performed with and without rat caecal contents. In the rat caecal contents tablets showed enhanced drug release due to degradation of chitosan coat by colonic colonic enzymes. The in vitro release studies in pH-6.8 phosphate buffer containing 2% w/v of rat caecal contents showed the cumulative percentage release of Ibuprofen after 26h as 31.94% ±0.59, 67.89% ± 0.45 and 55.87 % ± 0.45 and 82.52 % ± 0.92 respectively. Coatthickness and amount of chitosan controls the release rate. Formulations are best fitted with Korsmeyer-Peppas kinetics and mechanism of drug release was non-Fickian. FTIR studies reveals there is no drug-polysaccharide interaction. F1 formulation was a promising system for drug targeting to colon. Based on the obtained results chitosan as a press coat could target ibuprofen to the colon.

Cefuroxime is the second generation cephalosporin, which its intravenous and oral dosage forms are available. Oral route is the selective method for administration of most of the drugs. The aim of this study was formulating ‘for oral’ cefuroxime axetil suspensions. Minitab (ver.15) was used to design the formulations containing 125 mg of cefuroxime in 5 ml vehicle.After selecting the acceptable preparations, physical stability tests and other tests such as dissolution rate, pH, zeta potential and viscosity measurement of formulations were performed. From all 33 formulations, only 9 were selected to further investigation. Considering no sedimentation, the sedimentation volume was determined to be 1. The degrees of flocculation were also equal to 1. All selected formulations released the drug between 81-100% in 30 minutes which was acceptable according to the USP32 criteria. The results of assay test also proved that all formulations contain the drug in acceptable range (91-106%). The viscosity curves showed that the systems were pseudo plastic and thixotrop. Designed cefuroxime axetil formulations had good qualities and could be added as a new product to Iran drug marketing.