Development of Lyophilised Eudragit® Retard Nanoparticles for the Sustained Release of Clozapine via Intranasal Administration.

Clozapine (CZP) is the only effective drug in schizophrenia resistant to typical antipsychotics. However, existing dosage forms (oral or orodispersible tablets, suspensions or intramuscular injection) show challenging limitations. After oral administration, CZP has low bioavailability due to a large first-pass effect, while the i.m. route is often painful, with low patient compliance and requiring specialised personnel. Moreover, CZP has a very low aqueous solubility. This study proposes the intranasal route as an alternative route of administration for CZP, through its encapsulation in polymeric nanoparticles (NPs) based on Eudragit® RS100 and RL100 copolymers. Slow-release polymeric NPs with dimensions around 400-500 nm were formulated to reside and release CZP in the nasal cavity, where it can be absorbed through the nasal mucosa and reach the systemic circulation. CZP-EUD-NPs showed a controlled release of CZP for up to 8 h. Furthermore, to reduce mucociliary clearance and increase the residence time of NPs in the nasal cavity to improve drug bioavailability, mucoadhesive NPs were formulated. This study shows that the NPs already exhibited strong electrostatic interactions with mucin at time zero due to the presence of the positive charge of the used copolymers. Furthermore, to improve the solubility, diffusion and adsorption of CZPs and the storage stability of the formulation, it was lyophilised using 5% (w/v) HP-ß-CD as a cryoprotectant. It ensured the preservation of the NPs' size, PDI and charge upon reconstitution. Moreover, physicochemical characterisation studies of solid-state NPs were performed. Finally, toxicity studies were performed in vitro on MDCKII cells and primary human olfactory mucosa cells and in vivo on the nasal mucosa of CD-1 mice. The latter showed non-toxicity of B-EUD-NPs and mild CZP-EUD-NP-induced tissue abnormalities.

Design and Statistical Optimization of Novel Polyelectrolyte Complex Microbeads to Improve Entrapment Efficiency and Release Study of Vildagliptin.

BACKGROUND: The current research focused on the improvement of drug entrapment efficiency and release study of hydrophilic drug through polymer complextation. OBJECTIVE: Ionotropic gelation technique was utilised for the preparation of Polyelectrolyte complex microbeads of Vildagliptin using Sodium alginate and Eudragit RL100 and their performance was optimized by Central composite design. METHODS: Fourier Transform Infrared Spectroscopy, Scanning Electron Microscope, Differential Scanning Calorimetry, particle size, Drug Entrapment Efficiency, X-ray diffraction and in vitro drug release at 10hr were chosen for evaluating formulated microbeads. The impact of independent variables like concentration of sodium alginate and eudragit RL100 was examined over dependent responses. RESULTS: The interpretation of XRD, SEM, DSC, and FTIR affirmed no drug excipients interference and confirmed formation of polyelectrolyte complex microbeads. For complex microbeads, the maximum and minimum drug release after 10 hours was obtained as 96.23.5% and 89.45%, respectively. The 32 central composite design was further used to obtain response surface graph and the values for the particle size, DEE and Drug release were retained as 0.197, 76.30 % and 92.15%, respectively for the optimize batch. CONCLUSION: The result suggested the combination of two polymers (Sodium alginate and Eudragit RL100) were suitable for improving the entrapment efficiency of hydrophilic drug (Vildagliptin). The central composite design (CCD) technique is an effective tool for obtaining optimal drug delivery systems of Vildagliptin polyelectrolyte complex microbeads.

Development and Characterization of Eudragit-RL-100-Based Aceclofenac Sustained-Release Matrix Pellets Prepared via Extrusion/Spheronization.

Aceclofenac (AC) is a nonsteroidal anti-inflammatory drug used in the treatment of chronic pain in conditions such as rheumatoid arthritis, with frequent administration during the day. The formulation of sustained release matrix pellets can provide a promising alternative dosage form that controls the release of the drug, with less blood fluctuation and side effects-especially those related to the gastric system. The extrusion/spheronization technique was used to formulate AC matrix pellets. The response surface methodology (version 17.2.02.; Statgraphics Centurion) was used to study the impacts of Eudragit RL 100 and PVP K90 binder solution concentrations on the pellets' wet mass peak torque, pellet size, and the release of the drug. Statistically, a significant synergistic effect of PVP K90 concentration on the peak torque and pellet size was observed (p = 0.0156 and 0.031, respectively), while Eudragit RL 100 showed significant antagonistic effects (p = 0.042 and 0.013, respectively). The peak torque decreased from 0.513 ± 0.022 to 0.41 ± 0.021 when increasing the Eudragit RL 100 from 0 to 20%, and the pellet size decreased from 0.914 ± 0.047 to 0.789 ± 0.074 nm. The tested independent factors did not significantly affect the drug release in the acidic medium within 2 h, but these pellet formulae maintained the drug release at less than 10% in the acidic medium (pH 1.2), which may decrease gastric irritation side effects. In contrast, a highly significant synergistic effect of Eudragit and highly antagonistic effect of the PVP solution on drug release in the alkaline-pH medium were observed (p = 0.002 and 0.007, respectively). The optimized pellet formula derived from the statistical program, composed of 3.21% Eudragit and 5% PVP solution, showed peak torque of 0.861 ± 0.056 Nm and pellet size of 1090 ± 85 µm, and resulted in a significant retardation effect on the release after 8 h compared to the untreated drug.

Establishment and characterization of lung co-culture spheroids for paclitaxel loaded Eudragit® RL 100 nanoparticle evaluation.

3D cell cultures are regarded as a better and more relevant approach for screening drugs and therapeutics, particularly due to their likeness with the in vivo conditions. Spheroids offer an intermediate platform between in vitro and in vivo models, for conducting tumor-based investigations. In this study, a simple setup was developed for consistent generation of lung co-culture spheroids, which were developed using the cancer cell lines A549, NCI H460, and fibroblast cells WI-38. The potential of these spheroids for evaluating the toxicity of Eudragit® RL 100 nanoparticles (ENP) was explored. Monodisperse ENP, having the size range of 140-200 nm was prepared using the nanoprecipitation method. These were loaded with the poorly water-soluble anticancer drug paclitaxel. The evaluation of toxicity and uptake of drug-loaded ENP revealed that 2D monolayers were more sensitive to treatment than 3D spheroids. Within spheroids, co-cultures were more resistant to the treatment than monocultures. Overall, our findings demonstrated that the lung co-culture spheroids were a suitable model for accelerating the efficacy and toxicity-related investigations of novel drug delivery systems.

Polyvinyl Alcohol/Chitosan Single-Layered and Polyvinyl Alcohol/Chitosan/Eudragit RL100 Multi-layered Electrospun Nanofibers as an Ocular Matrix for the Controlled Release of Ofloxacin: an In Vitro and In Vivo Evaluation.

A novel nanofiber insert was prepared with a modified electrospinning method to enhance the ocular residence time of ofloxacin (OFX) and to provide a sustained release pattern by covering hydrophilic polymers, chitosan/polyvinyl alcohol (CS/PVA) nanofibers, with a hydrophobic polymer, Eudragit RL100 in layers, and by glutaraldehyde (GA) cross-linking of CS-PVA nanofibers for the treatment of infectious conjunctivitis. The morphology of the prepared nanofibers was studied using scanning electron microscopy (SEM). The average fiber diameter was found to be 123 ± 23 nm for the single electrospun nanofiber with no cross-linking (OFX-O). The single nanofibers, cross-linked for 10 h with GA (OFX-OG), had an average fiber diameter of 159 ± 30 nm. The amount of OFX released from the nanofibers was measured in vitro and in vivo using UV spectroscopy and microbial assay methods against Staphylococcus aureus, respectively. The antimicrobial efficiency of OFX formulated in cross-linked and non-cross-linked nanofibers was affirmed by observing the inhibition zones of Staphylococcus aureus and Escherichia coli. In vivo studies using the OFX nanofibrous inserts on a rabbit eye confirmed a sustained release pattern for up to 96 h. It was found that the cross-linking of the nanofibers by GA vapor could reduce the burst release of OFX from OFX-loaded CS/PVA in one layer and multi-layered nanofibers. In vivo results showed that the AUC0-96 for the nanofibers was 9-20-folds higher compared to the OFX solution. This study thus demonstrates the potential of the nanofiber technology is being utilized to sustained drug release in ocular drug delivery systems.

Moxifloxacin Hydrochloride-Loaded Eudragit® RL 100 and Kollidon® SR Based Nanoparticles: Formulation, In vitro Characterization and Cytotoxicity.

BACKGROUND: Considering the low ocular bioavailability of conventional formulations used for ocular bacterial infection treatment, there is a need to design efficient novel drug delivery systems that may enhance precorneal retention time and corneal permeability. AIM AND OBJECTIVE: The current research focuses on developing nanosized and non-toxic Eudragit® RL 100 and Kollidon® SR nanoparticles loaded with moxifloxacin hydrochloride (MOX) for its prolonged release to be promising for effective ocular delivery. METHODS: In this study, MOX incorporation was carried out by spray drying method aiming ocular delivery. In vitro characteristics were evaluated in detail with different methods. RESULTS: MOX was successfully incorporated into Eudragit® RL 100 and Kollidon® SR polymeric nanoparticles by a spray-drying process. Particle size, zeta potential, entrapment efficiency, particle morphology, thermal, FTIR, NMR analyses and MOX quantification using HPLC method were carried out to evaluate the nanoparticles prepared. MOX loaded nanoparticles demonstrated nanosized and spherical shape while in vitro release studies demonstrated modified-release pattern, which followed the Korsmeyer-Peppas kinetic model. Following the successful incorporation of MOX into the nanoparticles, the formulation (MOX: Eudragit® RL 100, 1:5) (ERL-MOX 2) was selected for further studies because of its better characteristics like cationic zeta potential, smaller particle size, narrow size distribution and more uniform prolonged release pattern. Moreover, ERLMOX 2 formulation remained stable for 3 months and demonstrated higher cell viability values for MOX. CONCLUSION: In vitro characterization analyses showed that non-toxic, nano-sized and cationic ERL-MOX 2 formulation has the potential of enhancing ocular bioavailability.

Pickering nano-emulsions stabilized by Eudragit RL100 nanoparticles as oral drug delivery system for poorly soluble drugs.

The purpose of this study was to develop Pickering water-in-oil nano-emulsions only stabilized by Eudragit RL100 nanoparticles (NPs), in order to increase the nano-emulsion stability and create a barrier to improve the drug encapsulation and better control the drug release. The first part of this study was dedicated to investigating the nano-emulsion formulation by ultrasonication and understanding the interfacial behavior and role of NPs in the stabilization of the water/oil interface. The focus was on the surface coverage in the function of the formulation parameters (volume fractions) to disclose the extents and limitations of the process. The main physicochemical analysis of the Pickering nano-emulsions was performed by dynamic light scattering and transmission electron microscopy. On the other hand, the second experimental approach was dedicated to understanding the interfacial behavior of the Eudragit RL100 NPs toward a model water/oil interface, using a dynamic tensiometer with axisymmetric drop shape analysis. The study investigated the NPs' adsorption, as well as their rheological behavior. The aim of this part was to reveal the main phenomena that govern the interactions between NPs and the interface in order to understand the origin of Pickering nano-emulsions' stability. The last part of the study was concerned with the stability and in vitro release of a model encapsulated drug (ketoprofen) in a gastric and simulated intestinal environment. The results showed that Pickering nano-emulsions significantly improved the resistance to gastric pH, inducing a significantly slower drug release compared to classical nano-emulsions' stabilized surfactants. These Pickering nano-emulsions appear as a promising technology to modify the delivery of a therapeutic agent, in the function of the pH, and can be, for instance, applied to the oral drug delivery of poorly soluble drugs.

Eudragit RL100 Based Moxifloxacin Hydrochloride and Ketorolac Tromethamine Combination Nanoparticulate System for Ocular Drug Delivery.

BACKGROUND: Bacterial conjunctivitis is a serious ocular infection if left untreated. It is caused by several species of bacteria like Pseudomonas, Staphylococcus and Mycobacterium. OBJECTIVE: The present investigation explores the development and characterization of moxifloxacin hydrochloride and ketorolac tromethamine combination loaded Eudragit RL 100 nanosuspension for ocular drug delivery in order to overcome the problems associated with conventional dosage forms. METHODS: The nanosuspension prepared by nanoprecipitation technique showed successful entrapment of both water-soluble drugs in the polymer matrix indicated by their % entrapment efficiencies. RESULTS: Formulations showed a mean particle size <200 nm with narrow size distribution and positive surface charge due to the presence of quaternary ammonium groups of Eudragit RL100. FTIR study revealed compatibility among the components, while a reduction in the crystallinity of formulation was observed in the PXRD study. The release of both the drugs was found to be sustained in nanosuspension as compared to commercial eyedrops. Ex vivo studies showed increased transcorneal permeation of drugs from nanosuspension, where approximately 2.5-fold and 2-fold increase in the permeation was observed for moxifloxacin hydrochloride and ketorolac tromethamine, respectively. The formulation was stable at 4°C and room temperature. CONCLUSION: Due to their sustained release, positive surface charge and higher transcorneal permeation, this will be a promising ocular drug delivery.

Data on statistical experimental design to formulate amphotericin B-loaded Eudragit RL100 nanoparticles coated with hyaluronic acid for the treatment of vulvovaginal candidiasis.

Data described in this article are related to the research article entitled "Amphotericin B-loaded Eudragit RL100 nanoparticles coated with hyaluronic acid (AMP EUD nanoparticles/HA) for the treatment of vulvovaginal candidiasis" [1]. In this work, we report original data on the statistical experimental design to formulate uncoated AMP EUD nanoparticles, data on the validation of spectrophotometric method to quantify the AMP released from uncoated EUD nanoparticles and coated with HA to obtain the in vitro drug release profiles as well as the drug encapsulation efficiency. In addition, we describe original data on characterization, including diameter size, polydispersity index, zeta potential, FTIR, DSC/TG, and XRD; data on diameter of in vitro inhibition halos of Candida albicans; and on the vaginal burden of infected animals treated with uncoated AMP EUD nanoparticles and AMP EUD nanoparticles/HA. Finally, different histological sections of endocervix collected from treated and untreated animals were inserted into this manuscript.

Amphotericin B-loaded Eudragit RL100 nanoparticles coated with hyaluronic acid for the treatment of vulvovaginal candidiasis.

The treatment of vulvovaginal candidiasis (VVC) is based on oral and vaginal formulations which show limited effectiveness. In this study, amphotericin B-loaded Eudragit RL100 nanoparticles coated with hyaluronic acid (AMP EUD nanoparticles/HA) were developed to overcome the drawbacks of the conventional formulations. AMP EUD nanoparticles/HA were synthesized by nanoprecipitation, formulated by statistical experimental design, and characterized. AMP release from EUD nanoparticles/HA and its antifungal activity in a murine model of VVC were evaluated. Nanoparticles showed 147.6 ±â€¯16.7 nm of diameter, 0.301 ±â€¯0.09 of polydispersity index, - 29.9 ±â€¯3.76 mV of zeta potential, and 87.27 % of encapsulation efficiency. They released about 81 % of AMP in 96 h; and provided the elimination of 100 % of the vaginal fungal burden in 24 h. It was suggested that the AMP EUD nanoparticles/HA penetrated into the vaginal epithelium via CD44 receptors. These AMP EUD nanoparticles/HA represent a non-conventional vaginal formulation to improve the treatment of VVC.

In situ composite ion-triggered gellan gum gel incorporating amino methacrylate copolymer microparticles: a therapeutic modality for buccal applicability.

The aim of the current investigation is to delineate the buccal applicability of an in situ composite gel containing aceclofenac (AC) amino methacrylate copolymer microparticles (MPs), surmounting limitations of oral existing conventional therapy. AC Eudragit RL100 MPs were fabricated and statistically optimized using 2241 factorial design. Better buccal applicability and enhanced localization were achieved by combining the optimum MPs with in situ ion-activated gellan gum gel. The crosslinking and gelation of in situ gel were investigated by morphological and solid state characterizations. Suitability for buccal delivery and in vivo therapeutic efficacy in inflammation model of rats were also assessed. Results showed that the best performing formula displayed particle size (PS) of 51.00 µm and high entrapment efficiency (EE%) of 94.73%. MPs were successfully entrapped inside the gel network of the composite system. Gelation tendency, pH, shear-thinning properties and mucoadhesivity of the prepared in situ composite gel guaranteed its buccal suitability. Sustained AC release features and promising in vitro anti-arthritic response were also demonstrated. Moreover, consistent and prolonged in vivo anti-inflammatory effect was achieved, relative to standard AC. Taken together; this study proves the potential of in situ composite gel as an appropriate therapeutic proposal for AC buccal delivery.

Characterization and stability evaluation of nanoencapsulated epoxylignans.

3',6-dimethoxy-3'',4''-(methylenedioxy)-2,5-epoxylignan-4'-ol (DMEO), an epoxylignan isolated from Piper nigrum, has currently captured attention for its potential antitumor effect. However, low stability is limiting its therapeutic application. The application of nanocapsulation would be the main strategy for overcoming this problem. DMEO-loaded nanocapsules were prepared by an emulsion-diffusion method using Eudragit RL 100 (at concentrations of 1, 1.5 and 2%) and polyvinyl alcohol. As the polymer content increased, the encapsulation efficiency and mean particle size also increased. After 6 months of storage at 25°C (0% RH), no crystalline peaks were observed in the diffraction patterns of all nanocapsules, thereby suggested that the physical stability of nanoencapsulated DMEO was not affected by the concentration ratio of the polymer-stabilizer combinations.

Vildagliptin loaded triangular DNA nanospheres coated with eudragit for oral delivery and better glycemic control in type 2 diabetes mellitus.

Diabetes mellitus type 2 is a multidimensional disease associated with poor glycemic control through compromised sensitivity of pancreatic islet α and ß cells against glucose and dwindled secretion of insulin which is linked with the quantity of incretin hormones that are abridged by dipeptidyl peptidase-4 (DPP-4) in diseased condition. Vildagliptin (VG) inhibits DPP-4 therefore regulates the incretins that conversely maintains glycemic control. The safe reach and absorption of VG from intestine was dubious. Therefore we used Electrostatic Attraction Method to develop drug loaded DNA nanotechnology triangles coated by Eudragit (Eud) to make stable nanospheres of Vildagliptin (VG). We further analyzed the formulated nanospheres by AFM, XRD, DSC, SEM, TGA, ATR-FTIR and native PAGE. Additionally the efficacy of formulated nanospheres for drug release and glycemic control was assessed in Db/Db mouse. Our results showed that formulated nanospheres are smooth, spherical, stable and uniform in size ranging from 500 to 2000 nm with drug entrapment efficiency up to 95 ± 2% and extended drug release up to 15 ± 2 h. FTIR and DSC results confirmed the absence of VG-DNA-Eud interaction and XRD studies revealed a change in the crystalline status of the VG in nanospheres. Ex-vivo studies indicate that Eud-DNA-VG nanospheres effectively bypasses the acidic pH of the stomach and enhances glycemic control in Db/Db mouse without any risk of pancreatitis or pancreatic cancer. To the best of our knowledge, this is the first study conclusively reporting that VG loaded DNA Nano-architects coated with Eudragit are stable, safe and may improve therapeutic outcomes after oral delivery.

Development of a nanoprecipitation method for the entrapment of a very water soluble drug into Eudragit RL nanoparticles.

Rivastigmine hydrogen tartrate (RHT), one of the potential cholinesterase inhibitors, has received great attention as a new drug candidate for the treatment of Alzheimer's disease. However, the bioavailability of RHT from the conventional pharmaceutical forms is low because of the presence of the blood brain barrier. The main aim of the present study was to prepare positively charged Eudragit RL 100 nanoparticles as a model scaffold for providing a sustained release profile for RHT. The formulations were evaluated in terms of particle size, zeta potential, surface morphology, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC). Drug entrapment efficiency and in vitro release properties of lyophilized nanoparticles were also examined. The resulting formulations were found to be in the size range of 118 nm to 154 nm and zeta potential was positive (+22.5 to 30 mV). Nanoparticles showed the entrapment efficiency from 38.40 ± 8.94 to 62.00 ± 2.78%. An increase in the mean particle size and the entrapment efficiency was observed with an increase in the amount of polymer. The FTIR, XRD, and DSC results ruled out any chemical interaction between the drug and Eudragit RL100 polymer. RHT nanoparticles containing low ratio of polymer to drug (4:1) presented a faster drug release and on the contrary, nanoparticles containing high ratio of polymer to drug (10:1) were able to give a more sustained release of the drug. The study revealed that RHT nanoparticles were capable of releasing the drug in a prolonged period of time and increasing the drug bioavailability.

A quality by design approach on polymeric nanocarrier delivery of gefitinib: formulation, in vitro, and in vivo characterization.

Gefitinib is an anticancer agent which acts by inhibiting epidermal growth factor receptor tyrosine kinase receptors. The aim of the present study was to prepare gefitinib nanosuspension. Gefitinib was encapsulated in Eudragit® RL100 and then dispersed in stabilizer solution, polyvinyl alcohol, and polyvinylpyrrolidone K30. Nanosuspension was prepared by using homogenization and ultrasonication techniques. The quality by design approach was also used in the study to understand the effect of critical material attributes (CMAs) and critical processing parameters (CPPs) on critical quality attributes and to improve the quality and safety of formulation. To study the effect of CMAs and CPPs, 23 full factorial design was applied. The particle size, polydispersity index, and zeta potential of the optimized solution were 248.20 nm, 0.391, and -5.62 mV, respectively. Drug content of the optimized nanoformulation was found to be 87.74%±1.19%. Atomic force microscopy studies of the optimized formulation confirmed that the prepared nanoparticles are smooth and spherical in nature. In vitro cytotoxicity studies of the nanosuspension on Vero cell line revealed that the formulation is nontoxic. The gefitinib nanosuspension released 60.03%±4.09% drug over a period of 84 h, whereas standard drug dispersion released only 10.39%±3.37% drug in the same duration. From the pharmacokinetic studies, half-life, Cmax, and Tmax of the drug of an optimized nanosuspension were found to be 8.65±1.99 h, 46,211.04±5,805.97 ng/mL, and 6.67±1.77 h, respectively. A 1.812-fold increase in relative bioavailability of nanosuspension was found, which confirmed that the present formulation is suitable to enhance the oral bioavailability of gefitinib.

Hydrophilic drug encapsulation in shell-core microcarriers by two stage polyelectrolyte complexation method.

In this study a protocol exploiting the combination of the ultrasonic atomization and the complexation between polyelectrolytes was developed to efficiently encapsulate a hydrophilic chemotherapeutic agent essentially used in the treatment of colon cancer, 5-fluorouracil, in enteric shell-core alginate-based microcarriers. The atomization assisted by ultrasound allowed to obtain small droplets by supplying low energy and avoiding drug degradation. In particular microcarriers were produced in a home-made apparatus where both the core (composed of alginate, drug, and Pluronic F127) and shell (composed of only alginate) feed were separately sent to the coaxial ultrasonic atomizer where they were nebulized and placed in contact with the complexation bulk. With the aim to obtain microstructured particles of alginate encapsulating 5-fluorouracil, different formulations of the first complexation bulk were tested; at last an emulsion made of a calcium chloride aqueous solution and dichloromethane allowed to reach an encapsulation efficiency of about 50%. This result can be considered very interesting considering that in literature similar techniques gave 5-fluorouracil encapsulation efficiencies of about 10%. Since a single complexation stage was not able to assure microcarriers gastroresistance, the formulation of a second complexation bulk was evaluated. The solution of cationic and pH-insoluble Eudragit® RS 100 in dichloromethane was chosen as bulk of second-stage complexation obtaining good enteric properties of shell-core microcarriers, i.e. a 5-FU cumulative release at pH 1 (simulating gastric pH) lower than 35%. The formation of interpolyelectrolyte complex (IPEC) between countercharged polymers and the chemical stability of 5-FU in microcarriers were confirmed by FTIR analysis, the presence of an amorphous dispersion of 5-FU in prepared microparticles was also confirmed by DSC. Finally, shell-core enteric coated microcarriers encapsulating 5-fluorouracil were used to prepare tablets, which can be potentially used as oral administration dosage systems for their 5-fluorouracil slower release.

Design of eudragit RL nanoparticles by nanoemulsion method as carriers for ophthalmic drug delivery of ketotifen fumarate.

OBJECTIVES: Ketotifen fumarate (KF) is a selective and noncompetitive histamine antagonist (H1-receptor) that is used topically in the treatment of allergic conditions of rhinitis and conjunctivitis. The aim of this study was to formulate and improve an ophthalmic delivery system of KF. Ocular nanoparticles were prepared with the objective of reducing the frequency of administration and obtaining controlled release to improve the anti-inflammatory drug delivery. MATERIALS AND METHODS: In the present study, ocular KF loaded Eudragit RL 100 nanoparticles were prepared using O/W solvent diffusion method. The nanoparticles were evaluated for particle size, entrapment efficiency, surface morphology, X-ray diffraction (XRD), Fourier transform spectroscopy (FTIR), and differential scanning calorimetry (DSC). In vitro release and permeation studies were also carried out on nanoparticles. RESULTS: An average size range of 182 to 314.30 nm in diameter was obtained and encapsulation efficiency up to 95.0% was observed for all the formulations. Drug release for all formulations after 24 hr was between 65.51% and 88.82% indicating effective controlled release property of KF. The mechanism of drug release for best formulation was found to be fickian diffusion mechanism. KF nanoparticles containing high polymer concentration (1:15) presented a faster drug release and a higher drug penetration; on the contrary, nanoparticles containing low polymer concentration (1:7.5) were able to give a more sustained release of the drug and thus a slower KF permeation through the cornea. CONCLUSION: The study revealed that KF NPs were capable of releasing the drug for a prolonged period of time and increasing the ocular bioavailability.

Formulation, characterization and evaluation of the effect of polymer concentration on the release behavior of insulin-loaded Eudragit(®)-entrapped mucoadhesive microspheres.

INTRODUCTION: The aim of this study was to use Eudragit(®) RL 100 (pH-independent polymer) and magnesium stearate (a hydrophobic droplet stabilizer) in combination to improve the controlled release effect of insulin-loaded Eudragit(®) entrapped microspheres prepared by the emulsification-coacervation technique. MATERIALS AND METHODS: Mucoadhesive insulin-loaded microspheres containing magnesium stearate and varying proportions of Eudragit(®) RL 100 were prepared by the emulsification-coacervation technique and evaluated for thermal properties, physicochemical performance, and in vitro dissolution in acidic and subsequently basic media. RESULTS: Stable, spherical, brownish, discrete, free-flowing and mucoadhesive insulin-loaded microspheres with size range of 14.20 ± 0.30-19.80 ± 0.60 µm and loading efficiency of 74.55 ± 1.05-75.90 ± 1.94% were formed. After 3 h, microspheres prepared with insulin: Eudragit(®) RL 100 ratios of 1:4, 1:6, and 1:8 released 73.40 ± 1.38, 66.20 ± 1.59, and 71.30 ± 1.27 (%) of insulin, respectively. CONCLUSION: The physicochemical and physico-technical properties of the microspheres developed in this study demonstrated the effectiveness of the Eudragit(®) RL entrapped mucoadhesive microspheres (prepared by the emulsification-coacervation technique using varying polymer concentration) as a carrier system for oral insulin delivery.

Ketoroloac tromethamine loaded nanodispersion incorporated into thermosensitive in situ gel for prolonged ocular delivery.

The present study was designed to improve the ocular availability of ketorolac tromethamine and to prolong its precorneal residence time for the treatment of postoperative ocular inflammation. Ketorolac tromethamine nanodispersions were successfully prepared by nanoprecipitation method using Eudragit(®) RL100. These nanodispersions were characterized in terms of particle size, zeta potential, entrapment efficiency and in vitro release. Consequently, the optimum nanodispersion was incorporated into thermosensitive in situ gel. The optimum gelling capacity was obtained by 20% Pluronic(®) F-127 and 14% Pluronic(®) F-127/1.5% HPMC K4m. The gelling temperature and gelation time of the in situ gels increased by decreasing the concentration of Pluronic(®) F-127. The mucoadhesive strength was significantly improved by the addition of HPMC. Incorporation of ketorolac tromethamine loaded nanodispersions into in situ gel bases sustained the release of ketorolac tromethamine, improved its ocular availability and prolonged its residence time without causing irritation to eye.

Comparative pharmacokinetics of a new oral long-acting formulation of doxycycline hyclate: A canine clinical trial.

Doxycicline is used in dogs as treatment of several bacterial infections, mycoplasma, chlamydia and rickettsial diseases. However, it requires long treatments and several doses to be effective. The aim of this study was to determine the pharmacokinetics of four formulations of doxycycline hyclate, administered orally, with different proportions of excipients, acrylic acid-polymethacrylate-based matrices, to obtain longer therapeutic levels than conventional formulation. Forty-eight dogs were randomly assigned in five groups to receive a single oral dose (20mg/kg) of doxycycline hyclate without excipients (control) or a long-acting formulation containing doxycycline, acrylic acid polymer, and polymethacrylate in one of the following four proportions: DOX1(1:0.25:0.0035), DOX2(1:0.5:0.0075), DOX3 (1:1:0.015), or DOX4(1:2:0.0225). Temporal profiles of serum concentrations were obtained at several intervals after each treatment. Therapeutic concentrations were observed for 60h for DOX1 and DOX4, 48h for DOX2 and DOX3 and only 24h for DOX-C. None of the pharmacokinetic parameter differed significantly between DOX1 and DOX2 or between DOX3 and DOX4; however, the findings for the control treatment were significantly different compared to all four long-acting formulations. Results indicated that DOX1 had the most adequate pharmacokinetic-pharmacodynamic relationships for a time-dependent drug and had longer release times than did doxycycline alone. However, all four formulations can be effective depend on the minimum effective serum doxycycline concentration of the microorganism being treated. These results suggest that the use of any of these formulations can reduce the frequency of administration, the patient's stress, occurrence of adverse effects and the cost of treatment.