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Naproxen is a non-steroidal anti-inflammatory drug which can be used for the treatment of inflammatory disorders like uveitis and arthirit rheumatoid. The aim of the present study was to investigate the physicochemical characteristics of naproxen-PLGA nanoparticles. The nanoparticles of naproxen with PLGA were formulated using the solvent evaporation/extraction technique (the single emulsion technique). Several process parameters i.e., drug/polymer ratio, aqueous phase volume and speed of homogenization were considered with the aim of achieve optimal preparation conditions. The physicochemical characteristics of nanoparticles were studied applying particle size analysis, differential scanning calorimetry, X-ray crystallography, Fourier transform infrared spectroscopy and scanning electron microscopy. The release rate of naproxen from various drug/polymer nanoparticles was investigated as well. All the prepared formulations using PLGA resulted in nano-range size particles (352-571 nm) with spherical smooth morphology. The nanoparticles of naproxen-PLGA displayed lower crystallinity with no chemical interactions between the drug and polymer molecules. The nanoparticles exhibited the slower release of drug in comparison with the intact drug and the physical mixtures. According of these findings, formulation of the naproxen-PLGA nanoparticles was able to improve the physicochemical characteristics of the drug and possibly will increase the anti-inflammatory effects of drug following its ocular or intra-joint administration.

This study was conducted to investigate the effects of HPMC (K4M and K100M) as well as tragacanth on the drug release rate of diltiazem (DLTZ) from matrix tablets prepared by direct compression method. Mechanism of drug transport through the matrices was studied by fitting the release data to the 10 kinetic models. 3 model independent parameters; i. e., mean dissolution time (MDT), mean release rate (MRR) and release rate efficacy (RE) as well as 5 time point approaches were established to compare the dissolution profiles. To find correlation between fraction of drug released and polymer’s molecular weight, dissolution data were fitted into two proposed equations. All polymers could sustain drug release up to 10 h. The release data were fitted best to Peppas and Higuchi square root kinetic models considering squared correlation coefficient and mean percent error (MPE). RE and MRR were decreased when polymer to drug ratio was increased. Conversely, t 60% was increased with raising polymer /drug ratio. The fractions of drug released from the formulations prepared with tragacanth were more than those formulated using the same amount of HPMC K4M and HPMC K100M. Preparation of DLTZ matrices applying HPMCK4M, HPMC K100M and tragacanth could effectively extend the drug release.

PURPOSE. Results of previous studies on the benefits of ocular drug delivery using polymeric mucoadhesive nanoparticles suggested longer presence and better penetration of nanoparticles, and, thus, increased effect and bioavailability of drugs entrapped in nanoparticles. In this study, a novel polymer, poly beta-amino ester, was used for the preparation of triamcinolone acetonide-loaded nanoparticles using a modified emulsification/solvent diffusion method. METHODS. Mucoadhesiveness studies, in vitro drug release, x-ray powder diffraction, differential scanning calorimetry, and scanning electron microscopy were used for physicochemical characterization of nanoparticles. Thirty-six hours after inducing uveitis by intravitreal injection of a lipopolysaccharide, sampling from the aqueous humor was done and inflammatory factors, such as cell, protein, nitric oxide, and prostaglandin E2, were compared. RESULTS. Nanoparticles with a mean size of 178 nm and drug loading of 5.3% were prepared and used for in vivo studies in rabbits with uveitis. Higher anti-inflammatory effect was observed for polymeric nanoparticles of triamcinolone acetonide compared with microparticles of prednisolone acetate and triamcinolone acetonide, and an equal effect compared with subconjunctival injection of triamcinolone acetonide in terms of inhibiting inflammation and inflammatory mediators. CONCLUSIONS. It can be concluded that polymeric nanoparticles of triamcinolone acetonide will provide as good an anti-inflammatory effect as the subconjunctival injection method and are better compared with other drug delivery systems.

The rapidly growing applications of antibody-based therapeutics requires novel approaches to develop efficient drug delivery systems in which biodegradable polymeric nanoparticles are amongst the best candidates. In the present study bevacizumab loaded PLGA nanoparticles were formulated by water-in-oil-in-water emulsion method. Protein inactivation and aggregation are the major drawbacks of this technique. Therefore protective ability of various stabilizers was studied during entrapment process. Probable changes in VEGF₁₆₅ binding capability of bevacizumab was assayed by ELISA which portrays the antibody's bio-efficiency. Probable breakage of bevacizumab and its secondary and tertiary structural integrity upon entrapment were analyzed by SDS-PAGE and circular dichroism spectroscopy, respectively. In vitro and ex vivo released bevacizumab from the prepared nanoparticles was also investigated. Results revealed that the protein interfacial adsorption is the foremost destabilizing factor in the double emulsion method and incorporation of appropriate concentrations of albumin could protect bevacizumab against entrapment stress. Ex vivo release results, in rabbit vitreous, indicated the ability of prepared nanoparticles in prolonged release of the active antibody. Consequently this approach was an attempt to achieve sustained release PLGA nanoparticle formulation with the aim of protecting integrity and performance of entrapped bevacizumab.

The purpose of this work was to improve the efficacy of triamcinolone acetonide (TA) in the treatment of endotoxin-induced uveitis (EIU) using a polymeric nanoparticulate drug delivery system. Poly( d , l -lactide-co-glycolide) (PLGA) nanoparticles were prepared using a modified emulsification/solvent diffusion method. Processing factors affecting loading and size were also studied. After physicochemical studies including in vitro release, X-ray powder diffraction, differential scanning calorimetry, and scanning electron microscopy, in vivo studies were conducted using nanoparticles sized 195 nm with 3.16% drug loading. Inflammatory factors such as flare, cell, and fibrin were studied in rabbit’s eye over 96 h period, using laser flare meter and slit lamp examination. Inflammatory mediators such as NO, PGE2, cell, and protein were measured quantitatively 36 h after intravitreal injection of endotoxin in aqueous humor, and the therapeutic effects were compared in different groups. Results indicated statistically significant differences between the effect of nanoparticles in the treatment of EIU compared to microparticles of TA and prednisolone acetate (PA). There were no significant differences between the effects of TA injection and TA nanoparticles. In conclusion, sustain release biodegradable TA nanoparticles are potential new topical treatment options which can provide better patient compliance.

Seven free-radical-scavenging phenolic compounds including five flavonoids, rutin (1), chrysoeriol 7-O-rutinoside (2), kaempferol 3-O-glucoside (3), chrysoeriol 7-O-glucoside (4) and naringenin (5), and two phenylethanoid glycosides, forsythoside B (6) and acteoside (7) were isolated from the methanol extract of the aerial parts of the Iranian medicinal plant Phlomis caucasica by reversed-phase preparative high-performance liquid chromatography (HPLC), and the structures of these compounds were elucidated by spectroscopic means. The free-radical-scavenging properties of 1-7 were assessed by 2,2-diphenyl-1-picryl hydrazyl (DPPH) assay. Among these compounds, forsythoside B (6) and acteoside (7) were found to be the most potent antioxidants with the RC(50) values of 4.97 and 4.27 microg/ml, respectively.