Effect of certain factors on binding of ketoprofen to human serum albumin

A study was made to investigate the interaction of Ketoprofen with human serum albumin [HAS] in isotonic Sorensen's phosphate buffer of pH 7.4 at 37°C. The equilibrium dialysis technique was used to assess factors influencing Ketoprofen binding to HSA. Results have demonstrated a marked binding of Ketoprofen to HSA. The binding characteristics were affected by certain factors. Increasing the concentration of the drug was accompanied by a reduction in the amount bound to HSA. While, binding of the drug with HSA was directly proportional to HSA concentration. Changing pH values had no effect on the binding of drug with HSA. Addition of three organic aliphatic acids, namely citric, tartaric and acetic acid to [HSA] did not result in significant changes in the values of binding parameters of drug to HSA, In contrast, the addition of succinic acid to albumin-Ketoprofen solution resulted in a decrease in the binding of drug to albumin. The addition of relatively large amounts of creatinine, uric acid and phenol failed to produce a significant decrease in Ketoprofen binding. In contrast, it has been found that urea more or less decreased Ketoprofen Binding and this decrease was concentration dependent. Regarding the effect of guanidines on the binding of Ketoprofen to HSA, it was found that both methylguanidine, guanidinosuccinic acid guanidinoacetic acid failed to induce a significant changes in values of binding parameters. The binding of Ketoprofen to HSA was examined in presence of four indolic compounds namely; indole-acetic acid, indican, indole-lactic acid and indole butyric acid. It was found that, all indolic compounds showed a significant decrease in Ketoprofen albumin binding and this decrease was concentration dependent. The order of inhibitory capacity was indole- lactic acid < indican < indole-acetic acid < indole-butyric acid

Labeling and evaluation of freeze-dried ofloxacine kits for [99m]Tc labeling

Ofloxacine was labeled with [99m]Tc. The labeling reaction was carried under the specified conditions. The yield of the labeled ofloxacine was determined using TLC and HPLC and it was higher than 95%. The radioactive preparation is able to localize in both bacterial and sterile inflammations induced by Escherichia coli and turpentine oil, which suggest that its accumulation is due to increased blood flow together with enhanced vascular permeability. Also the freeze-dried kits were designed for direct labeling technique. The solution of Sn-ofloxacine was sterilized by 0.22micro m millipore filtration and dispensed in a laminar flow. hood [1 ml/vial], then the vials were introduced in the lyophilizer. The process of lyophilization was continued for 24 h. At the end of the cycle, the vials were closed under nitrogen. The prepared ofloxacin freeze-dried kits have high radiochemical purity >/= 95% and it was stable for at least 8 h. after labeling

Ocular controlled delivery of brimonidine using liposomes as a particulate carrier

The ocular activity of a single dose of brimonidine 0.2% in solution and liposomal formulations was evaluated in 28 adult patients with recently diagnosed primary open angle glaucoma. Multilamellar liposomes were prepared from dipalmitoyl phosphatidcholine and cholesterol. Stearylamine and dicetyl phosphate were used to modify the net surface charge of liposomes. The evaluation of the performance of various formulations of the drug was assessed on the basis of the influence of the drug on the intraocular pressure. Results demonstrated that the intra-ocular activity of the drug using various liposomal formulations was greater than that of solution form. Moreover, concerning the liposomal surface charge, the drug activity was greatest for positively charged liposomes, less for neutral liposomes and least for negatively charged liposomes. This could be attributed to electrostatic attraction between the negatively charged surface of the corneal epithelial and positively charged liposomal surface. In conclusion, it was clearly observed that liposomal ophthalmic drug delivery system seems to be a promising approach for the selective targeting of the drug