Dendrimers as potential drug carriers. Part II. Prolonged delivery of ketoprofen by in vitro and in vivo studies.

Ketoprofen, a non-steroidal anti-inflammatory drug with well-known anti-inflammatory, antipyretic and analgesic properties, has low solubility in water and causes local or systemic disturbance in the gastrointestinal tract. In the present study we investigated the potential of polyamidoamine (PAMAM) dendrimers as drug carriers of ketoprofen by in vitro and in vivo studies. The in vitro release of ketoprofen from the drug-dendrimer complex is significantly slower compared to pure ketoprofen. Anti-nociceptive studies using the acetic acid-induced writhing model in mice showed a prolonged pharmacodynamic behavior for the ketoprofen-PAMAM dendrimer complex. Also, the blood level studies were investigated. We concluded that PAMAM dendrimers might be considered as a potential drug carrier of ketoprofen with a sustained release behavior under suitable conditions.

Solubility of nicotinic acid in polyamidoamine dendrimer solutions.

In the present study we investigated the effect of ethylenediamine (EDA) core polyamidoamine (PAMAM) dendrimers on the aqueous solubility of nicotinic acid. The aqueous solubility of nicotinic acid was measured in the presence of dendrimers at room temperature in distilled water. The effect of variables, such as pH condition, concentration, surface functional group and generation (molecule size) of dendrimer, has been investigated. Results showed that the solubility of nicotinic acid in the dendrimer solutions was proportional to dendrimer concentration, both amine and ester-terminated dendrimers caused the higher increase in nicotinic acid solubility at higher pH conditions. The order in which the dendrimers increased the solubility at a constant pH condition was G4>G3>G2>G1. In addition, at each pH, the solubility of nicotinic acid was greater in the presence of amine-terminated dendrimers compared to the amine ester-terminated dendrimers possessing the same number of surface functional groups. Under suitable conditions PAMAM dendrimers can be highly effective used to enhance the solubility of nicotinic acid.

Polyamidoamine dendrimers used as solubility enhancers of ketoprofen.

Ketoprofen is a non-steroidal anti-inflammatory drug which is not freely soluble in water and creates gastrointestinal problems. In the present study we investigated the potential of polyamidoamine (PAMAM) dendrimers to increase the solubility of ketoprofen. The effect of variables, such as pH condition, concentration and generation of dendrimer, has been investigated. The experimental results showed that the solubility of ketoprofen in the dendrimer solutions was proportional to dendrimer concentration. Under suitable conditions PAMAM dendrimers can be highly effective used to enhance the solubility of ketoprofen.

Dendrimers as potential drug carriers. Part I. Solubilization of non-steroidal anti-inflammatory drugs in the presence of polyamidoamine dendrimers.

The aqueous solubility of non-steroidal anti-inflammatory drugs (NSAIDs) Ketoprofen, Ibuprofen, Diflunisal and Naproxen were measured in the presence of the ethylenediamine (EDA) core polyamidoamine (PAMAM) dendrimers at 37 degrees C. The effect of concentration and generation of the PAMAM dendrimers has been investigated. Results showed that the solubility of NSAIDs in the PAMAM dendrimer solutions was approximately proportional to dendrimer concentration; the solubility of NSAIDs in higher generation PAMAM solutions was in fact higher that those in lower ones; the order of increased solubility of NSAIDs in PAMAM dendrimers at a constant dendrimer concentration and generation was Naproxen>Ketoprofen>Ibuprofen>Diflunisal. Under suitable conditions PAMAM dendrimers can be highly effective used to enhance the solubility of NSAIDs.

Tuning the diffusion dialysis performance by surface cross-linking of PPO anion exchange membranes--simultaneous recovery of sulfuric acid and nickel from electrolysis spent liquor of relatively low acid concentration.

The results of the development of the industrial diffusion dialysis technology and the unit based on it for sulfate acid recovery from nickel electrolysis waste have been considered. Unlike most acid recovery systems, this system has a relatively low acid concentration and the main aim is to recover both nickel and acid sulfate by recycling the waste and the recovered acid to the respective steps of electrolysis process. So the waste volume control seems to be the most important thing. To satisfy with this new request, the membrane is surface-cross-linked with aqueous ammonium to decrease waste volume expansion caused by the water osmosis. The results showed that the best membrane for such operation is the one that cross-linked at least 8 h with a volumetric expansion factor (volumetric ratio of waste to feed) less than 1.1. Pilot diffusional runs were conducted with this membrane at various feed flow rate and flow ratio of stripping water and feed. After comprehensively considering all factors, the range of feed flow and the flow ratio has been recommended to be 1.2-1.8 l/h and 1.05-1.1, respectively. Under these conditions, nickel leakage can be controlled within 4% and the acid recover ratio can attain as high as 66-72%. The recovered acid can be recycled to the back-extraction step by mixing it with high concentration acid and the waste recycled to the initial leaching stage by adjusting the acid concentration to recover valuable metal nickel and the residual acid. Therefore, the new technology discards nothing and shows many advantages whether in environmental aspect or economical aspect and thus should be deserved attention.