Gold nanoparticles: New routes across old boundaries.

In recent years, gold nanoparticles have emerged as unique non-invasive drug carriers for targeting drugs to their site of action. Their site specificity has helped in increasing drugs' efficacy at lower dose as well as reduction in their side effects. Moreover, their excellent optical properties and small size offer their utilization as diagnostic tools to diagnose tumors as well as other diseases.

Effect of experimental temperature on the permeation of model diffusants across porcine buccal mucosa.

The influence of experimental temperature on the permeability of model diffusants across porcine buccal mucosa was investigated in vitro. The permeability increased significantly as the experimental temperature was increased in increments of approximately 7°C. It was observed that the apparent permeability and temperature were related by an exponential relationship that conformed to the Arrhenius equation.

Relative bioavailability of chlorothiazide from mucoadhesive compacts in pigs.

The relative bioavailability of chlorothiazide from mucoadhesive polymeric compacts is compared to commercial oral suspension in pigs. A single-dose randomized study was conducted in 12 healthy pigs that are 9-10 weeks old. After overnight fasting, pigs were divided into two groups of six animals.

Porcine buccal mucosa as in vitro model: effect of biological and experimental variables.

Porcine buccal mucosa has been used as an in vitro model to assess the potential of delivering a molecule via the transbuccal route. However, permeation studies across porcine buccal mucosa show high variability due to various experimental and biological factors. The variability associated with the use of different mucosal regions, tissue storage conditions and tissue processing methods on drug permeation was investigated in this study.

Evaluation of polyethylene oxide compacts as gastroretentive delivery systems.

Compacts containing selected bioadhesive polymers, fillers, and binders were investigated for their potential as a bioadhesive gastroretentive delivery system to deliver water soluble and water insoluble compounds in the stomach. Compacts with 90:10, 75:25, and 60:40 of polyvinylpyrrolidone (PVP) and polyethylene oxide (PEO) were evaluated for swelling, dissolution, bioadhesion, and in vitro gastric retention. Compacts containing higher PEO showed higher swelling (111.

Porcine buccal mucosa as an in vitro model: relative contribution of epithelium and connective tissue as permeability barriers.

Porcine buccal mucosa has been extensively used as an in vitro model to study the permeability of various diffusants and to assess their potential to be delivered through the buccal route. The relative contribution of each component of the buccal mucosa on drug permeability was assessed in this study. The permeability of model diffusants decreased significantly with an increase in the mucosal thickness.

Transbuccal delivery of 5-aza-2 -deoxycytidine: effects of drug concentration, buffer solution, and bile salts on permeation.

Delivery of 5-aza-2 -deoxycytidine (decitabine) across porcine buccal mucosa was evaluated as an alternative to the complex intravenous infusion regimen currently used to administer the drug. A reproducible high-performance liquid chromatography method was developed and optimized for the quantitative determination of this drug. Decitabine showed a concentration-dependent passive diffusion process across porcine buccal mucosa.

Advances in buccal drug delivery.

The buccal route offers an attractive alternative for systemic drug delivery of drugs because of better patient compliance, ease of dosage form removal in emergencies, robustness, and good accessibility. Use of buccal mucosa for drug absorption was first attempted by Sobrero in 1847, and since then much research was done to deliver drugs through this route. Today, research is more focused on the development of suitable delivery devices, permeation enhancement, and buccal delivery of drugs that undergo a first-pass effect, such as cardiovascular drugs, analgesics, and peptides.

Interactions between mercury and dissolved organic matter--a review.

Dissolved organic matter (DOM) interacts very strongly with mercury, affecting its speciation, solubility, mobility, and toxicity in the aquatic environment. Strong binding of mercury by DOM is attributed to coordination of mercury at reduced sulfur sites within the organic matter, which are present at concentrations much higher than mercury concentrations found in most natural waters. The ability of organic matter to enhance the dissolution and inhibit the precipitation of mercuric sulfide, a highly insoluble solid, suggests that DOM competes with sulfide for mercury binding.