Effects of pre and post-treatments with dipyridamole in gentamicin-induced acute nephrotoxicity in the rat.

This study investigated the pretreatment and post-treatment effects of dipyridamole (20 mg/kg/day, p.o.) in gentamicin-induced acute nephrotoxicity in rats. Rats were administered gentamicin (100 mg/kg/day, i.p.) for 8 days. Gentamicin-administered rats exhibited renal structural and functional changes as assessed in terms of a significant increase in serum creatinine and urea and kidney weight to body weight ratio as compared to normal rats. Renal histopathological studies revealed a marked incidence of acute tubular necrosis in gentamicin-administered rats. These renal structural and functional abnormalities in gentamicin-administered rats were accompanied with elevated serum uric acid level, and renal inflammation as assessed in terms of decrease in interleukin-10 levels. Dipyridamole pretreatment in gentamicin-administered rats afforded a noticeable renoprotection by markedly preventing renal structural and functional abnormalities, renal inflammation and serum uric acid elevation. On the other hand, dipyridamole post-treatment did not significantly prevent uric acid elevation and renal inflammation, and resulted in comparatively less protection on renal function although it markedly reduced the incidence of tubular necrosis. In conclusion, uric acid elevation and renal inflammation could play key roles in gentamicin-nephrotoxicity. Dipyridamole pretreatment markedly prevented gentamicin-induced acute nephrotoxicity, while its post-treatment resulted in comparatively less renal functional protection.

Moxifloxacin loaded gelatin nanoparticles for ocular delivery: Formulation and in-vitro, in-vivo evaluation.

The current research focuses on developing positively charged gelatin nanoparticles loaded with moxifloxacin for its effective ocular delivery and controlled release in corneal eye layer. We selected type A gelatin because of its biodegradable and non-toxic nature as the polymer of choice for fabricating the nanoparticles by a modified two step desolvation technique. The produced nanoparticles were positively charged (+24±0.12mV) with a narrow particle size of 175±1.11nm as measured by dynamic light scattering (DLS). The in-vitro drug release from the nanoformulations exhibited a burst effect in the first hour followed by a controlled release of the drug for the subsequent 12h. The Korsmeyer-Peppas model showed better linearity and the formulations displayed non-Fickian drug release pattern. The optimized formulation was assessed for its utility as an anti-bacterial agent and its effectiveness was tested on the corneal eye surface of rabbits. The in-vivo tolerance tests revealed that the drug loaded nano-formulations was non-irritant to the ocular tissues indicating its safety. The in-vivo anti-bacterial activity of the nanosuspension was more effective against S. aureus than the commercially market product, MoxiGram®. Microbiological efficacy assessed against B. subtilus using cup-plate method suggested that our fabricated nanosuspension possess better anti-microbial activity as compared to the commercial agent, MoxiGram® revealing promising potentials for the currently developed gelatin based nanoformualtions.

Pharmacokinetic and pharmacodynamic studies of poly(amidoamine) dendrimer based simvastatin oral formulations for the treatment of hypercholesterolemia.

The aim of this investigation was to evaluate the in vivo potential of poly(amidoamine) dendrimers (PAMAM) based simvastatin (SMV) formulations as nanoscale drug delivery units for controlled release action of simvastatin. Drug-dendrimer complexes were prepared and characterized by Fourier transform infrared (FTIR) spectroscopy. In a pharmacodynamic study, the percent increase in cholesterol was less with PAMAM dendrimer formulations as compared to pure drug. The cholesterol level was increased to 20.92% with pure SMV, whereas it was 11.66% with amine dendrimer, 11.49% with PEGylated dendrimer, and 10.86% with hydroxyl dendrimer formulations. Reduction in the increase in triglyceride and low density lipoprotein level was also more prominent with the drug-dendrimer formulations. The order of increase in high density lipoprotein level was PEGylated PAMAM-SMV (4.04%) > PAMAM-amine-SMV (2.57%) > PAMAM-hydroxyl-SMV (1.48%) > pure SMV (1.09%). Dendrimer-SMV formulations showed better pharmacokinetic performances than pure SMV suspension. The peak plasma SMV concentration increased from 2.3 µg/mL with pure SMV to 3.8 µg/mL with dendrimer formulations. The dendrimer mediated formulation had 3-5 times more mean SMV residence time than pure SMV. Furthermore, SMV absorption and elimination rates were decreased significantly, showing controlled release of SMV from the dendrimer formulations.