Design, characterization, and evaluation of aceclofenac-loaded Eudragit RS 100 nanoparticulate system for ocular delivery.

The aim of the present study was to develop and evaluate positively charged nanoparticles of aceclofenac for ocular delivery. The nanoparticles were prepared by the nanoprecipitation method using Eudragit RS 100. The optimized nanoparticles were found to have narrow particle size range (238.9 ± 8 nm) with nearly spherical shape, positive zeta potential (40.3 ± 3.8). Higher entrapment efficiency of aceclofenac (94.53 ± 1.0%) with prolonged in vitro drug release profiles was also observed. Powder X-ray diffraction and differential scanning calorimetry studies indicated decrease in crystallinity of drug within the nanoparticulate polymeric matrix. The formulation was found to have higher permeation as compared to aceclofenac aqueous solution. Nanoparticle formulation was found to be quite stable and well tolerated with no signs of corneal damage. The in vivo studies involving the arachidonic acid-induced ocular inflammation in rabbits showed optimal efficacy of the nanoparticles with significantly higher inhibition of polymorphonuclear leukocytes migration (p < 0.05) and lid closure scores.

Aceclofenac oil drops: characterization and evaluation against ocular inflammation.

Ocular inflammatory diseases, such as uveitis, scleritis, episcleritis and dry eye syndrome are commonly treated with eye drop formulations. In the present study, attempts were made to prepare aceclofenac oil formulations to evaluate its transcorneal permeation and anti-inflammatory effect. Ophthalmic solutions of aceclofenac with or without (0.5% v/v) benzyl alcohol were formulated in different vegetable oils and permeation studies were carried out. Aceclofenac ophthalmic solution in linseed oil containing benzyl alcohol exhibited maximum permeation (4.42% in goat, 4.26% in sheep and 3.94% in buffalo) through corneas under study. The partition characteristics of aceclofenac in linseed oil reinforced the results of permeation studies. The optimized formulation (linseed oil containing benzyl alcohol) showed better stability profile. Linseed oil aceclofenac formulation showed significant inhibitory effect on ocular inflammation induced by arachidonic acid in rabbit eyes (p < .05) and hence it can be considered as a potential approach for treatment of ocular inflammatory conditions.

Enhancement of ocular efficacy of aceclofenac using biodegradable PLGA nanoparticles: formulation and characterization.

In the present study, an effort was made to design poly (D, L-lactide-co-glycolide) acid nanoparticles of aceclofenac by direct precipitation method. The nanoparticles were found to have adequate particle size range for ocular administration of 162.6 to 244.13 nm with nearly spherical shape and with zeta potential of - 21.5 to - 25.5 mV. Drug entrapment efficiency of nanoparticle formulations ranged from 42.9 to 92.68%. Differential scanning calorimetric (DSC) and powder X-ray diffraction (PXRD) studies depicted that the drug incorporated in nanoparticles was found to be in amorphous state. Moreover, nanoparticles showed prolonged in vitro drug release profile and followed Higuchi-square-root release kinetics. Nanoparticles showed two folds higher permeation than aqueous solution of aceclofenac. Nanoparticles were well tolerated with no signs of corneal damage in in vitro transcorneal permeation studies. The formulation was quite stable. In vivo ocular anti-inflammatory study in the rabbit eyes confirmed better efficacy of nanoparticles as compared with the aqueous solution and its potential application in ocular inflammatory conditions.

Formulation and characterization of clozapine and risperidone co-entrapped spray-dried PLGA nanoparticles.

In the current study, polylactide-co-glycolide (PLGA) nanoparticles entrapping both clozapine (CLZ) and risperidone (RIS) were formulated by spray-drying using Buchi Nano Spray Dryer B-90 (Flawil, Switzerland). Parameters such as inlet temperature, spray mesh diameter, sample flow rate, spray rate and applied pressure were optimized to produce nanoparticles having desired release profile using both low- and high-molecular weight PLGA polymer. Smallest size nanoparticle of size around 248 nm could be prepared using a 4.0 µm mesh diameter with low-molecular weight polymer. The load of CLZ and RIS was 126.3 and 58.2 µg/mg of polymer particles, respectively. Entrapment efficiency of drugs in PLGA nanoparticles was 94.74% for CLZ and 93.12% for RIS. Both the drugs released continuously from the nanoparticle formulations. PLGA nanoparticles formulated using low-molecular weight polymer released around 80% of the entrapped drug over 10 days of time. Nature of drug inside polymer particles was amorphous, and there was no chemical interaction of CLZ and RIS with polymer. Polymeric nanoparticles were found to be non-toxic in nature using PC12 cell line. This nanospray drying process proved to be suitable for developing polymeric nanoformulation delivering dual drugs for the treatment of Schizophrenia.

A clinical microbiological study of corneal ulcer patients at western Gujarat, India.

Corneal ulcer is a major cause of blindness throughout the world. When the cornea is injured by foreign particles, there are chances of infection by the organism and development of ulcer. Bacterial infection in the cornea is invariably an alteration of the defense mechanism of the outer eye. It is essential to determine the local etiology within a given region when planning a corneal ulcer management strategy. Laboratory evaluation is necessary to establish the diagnosis and to guide the antibiotic therapy. One hundred corneal ulcer patients were studied by collecting their corneal scraping samples and processing at Clinical Microbiology department of Shree Meghaji Petharaj Shah Medical College, Jamnagar, Gujarat, India during a period of 17 months. All clinical microbiology laboratory procedures followed standard protocols described in the literature. 40 (40%) patients from the age group of 20-70 years had been confirmed as - any organism culture positive - within the corneal ulcer patient population. Fungi were isolated from 26 (26%) corneal ulcer patients. The bacterial etiology was confirmed in 14 (14%) corneal ulcer patients. The major risk factors for mycotic keratitis were vegetative injury (16, (62%)), followed by conjunctivitis (4, (15%)), and blunt trauma (3, (11%)). Pseudomonas aeruginosa was the most commonly isolated bacterium (6, (43%)), followed by Proteus spp. (4, (29%)). Corneal Infections due to bacteria and filamentous fungi are a frequent cause of corneal damage. Microbiological investigation is an essential tool in the diagnosis of these infections. The frequency of fungal keratitis has risen over the past 20 to 30 years. Prognosis of bacterial corneal infection has improved since the introduction of specific antibacterial therapy.

Topical ocular delivery of fluoroquinolones.

INTRODUCTION: Topical fluoroquinolones are used in ophthalmology to treat ocular infections. They are bactericidal and inhibit bacterial DNA replication by inhibiting DNA gyrase and topoisomerase. Fluoroquinolones possess two ionizable groups: a carboxylic group (pKa1 = 5.5 - 6.34) and a heterocyclic group (pKa2 = 7.6 - 9.3), in the nucleus, which acquire charge at pH above and below the isoelectric point (pI = 6.75 - 7.78). At isoelectric point, fluoroquinolones remain unionized and show enhanced corneal penetration but exhibit reduced aqueous solubility and the drug may precipitate from aqueous solution. Aqueous ophthalmic solutions of fluoroquinolones are obtained by using hydrochloride or mesylate salt which is acidic and irritating to the eyes. Hence, pH of the solution is kept between 5 and 7 to ensure aqueous solubility and minimum ocular irritation. AREAS COVERED: This review gives an overview of various physicochemical and formulation factors affecting the ocular delivery of fluoroquinolones and strategies for getting higher ocular bioavailability for ocular delivery of fluoroquinolones. These strategies could be employed to improve efficacy of fluoroquinolones in eye preparation. EXPERT OPINION: Broad-spectrum antibacterials, such as the ophthalmic fluoroquinolones, are powerful weapons for treating and preventing potentially sight-threatening infections. The fourth-generation fluoroquinolones have quickly assumed an outstanding place in the ophthalmic applications. Especially valuable for their broad-spectrum coverage against Gram-positive and Gram-negative organisms, these agents have become the anti-infective of preference for many ophthalmologists. Moxifloxacin seems to be a promising powerful molecule among all fluoroquinolones for treatment of bacterial infections.

Eudragit RL 100-based nanoparticulate system of aceclofenac for ocular delivery.

The purpose of this study was to prepare Eudragit RL 100-based nanoparticles of aceclofenac by nanoprecipitation and evaluate the particle size, zeta potential, drug entrapment, particle morphology; in vitro drug release and in vivo efficacy. Change in drug-polymer ratio from 1:5 to 1:20 increased the particle size and entrapment efficiency. The particles showed sustained in vitro drug release which followed the Higuchi square-root kinetics. The results indicate that the nanoparticles release the drug by a combination of dissolution and diffusion. Based on the particle size (134.97 nm) and entrapment efficiency (95.73%), the formulation made with 1:10 drug-polymer ratio was selected for further studies. The particles were spherical with a polydispersity index of 0.186 and zeta potential of +30.5 mV. Powder X-ray diffraction and differential scanning calorimetry indicated decrease in crystallinity of drug in the nanoparticle formulation. In the in vitro permeation study, the nanoparticle formulation showed 2-fold higher permeation of drug through excised cornea compared to an aqueous solution of drug with no signs of corneal damage. The in vivo studies involving arachidonic acid-induced ocular inflammation in rabbits revealed significantly higher inhibition of polymorphonuclear leukocytes migration (p<0.05) and lid closure scores by the nanoparticle formulation compared with the aqueous solution. The formulation was quite stable to ensure two year shelf life at room temperature.

Design and evaluation of moxifloxacin hydrochloride ocular inserts.

The objective of the present investigation was to prepare and evaluate ocular inserts of moxifloxacin. An ocular insert was made from an aqueous dispersion of moxifloxacin, sodium alginate, polyvinyl alcohol, and dibutyl phthalate by the film casting method. The ocular insert (5.5 mm diameter) was cross-linked by CaCl2 and was coated with Eudragit S-100, RL-100, RS-100, E-100 or L-100. The in vitro drug drainage/permeation studies were carried out using an all-glass modified Franz diffusion cell. The drug concentration and mucoadhesion time of the ocular insert were found satisfactory. Cross-linking and coating with polymers extended the drainage from inserts. The cross-linked ocular insert coated with Eudragit RL-100 showed maximum drug permeation compared to other formulations.

Enhancement of bioavailability of cefpodoxime proxetil using different polymeric microparticles.

Poorly water-soluble drugs such as cefpodoxime proxetil (400 µg/ml) offer a challenging problem in drug formulation as poor solubility is generally associated with poor dissolution characteristics and thus poor oral bioavailability. According to these characteristics, preparation of cefpodoxime proxetil microparticle has been achieved using high-speed homogenization. Polymers (methylcellulose, sodium alginate, and chitosan) were precipitated on the surface of cefpodoxime proxetil using sodium citrate and calcium chloride as salting-out agents. The pure drug and the prepared microparticles with different concentrations of polymer (0.05-1.0%) were characterized in terms of solubility, drug content, particle size, thermal behavior (differential scanning calorimeter), surface morphology (scanning electron microscopy), in vitro drug release, and stability studies. The in vivo performance was assessed by pharmacokinetic study. The dissolution studies demonstrate a marked increase in the dissolution rate in comparison with pure drug. The considerable improvement in the dissolution rate of cefpodoxime proxetil from optimized microparticle was attributed to the wetting effect of polymers, altered surface morphology, and micronization of drug particles. The optimized microparticles exhibited excellent stability on storage at accelerated condition. The in vivo studies revealed that the optimized formulations provided improved pharmacokinetic parameter in rats as compared with pure drug. The particle size of drug was drastically reduced during formulation process of microparticles.