The Influence of Shape Parameters on Unidirectional Drug Release from 3D Printed Implants and Prediction of Release from Implants with Individualized Shapes

The local treatment of diseases by drug-eluting implants is a promising tool to enable successful therapy under potentially reduced systemic side effects. Especially, the highly flexible manufacturing technique of 3D printing provides the opportunity for the individualization of implant shapes adapted to the patient-specific anatomy. It can be assumed that variations in shape can strongly affect the released amounts of drug per time. This influence was investigated by performing drug release studies with model implants of different dimensions. For this purpose, bilayered model implants in a simplified geometrical shape in form of bilayered hollow cylinders were developed. The drug-loaded abluminal part consisted of a suitable polymer ratio of Eudragit^® RS and RL, while the drug-free luminal part composed of polylactic acid served as a diffusion barrier. Implants with different heights and wall thicknesses were produced using an optimized 3D printing process, and drug release was determined in vitro. The area-to-volume ratio was identified as an important parameter influencing the fractional drug release from the implants. Based on the obtained results drug release from 3D printed implants with individual shapes exemplarily adapted to the frontal neo-ostial anatomy of three different patients was predicted and also tested in an independent set of experiments. The similarity of predicted and tested release profiles indicates the predictability of drug release from individualized implants for this particular drug-eluting system and could possibly facilitate the estimation of the performance of customized implants independent of individual in vitro testing of each implant geometry.

Methacrylic acid-methyl methacrylate and related copolymers (Eudragit®)

Moisture sorption by polymeric carriers used in amorphous solid dispersion (ASD) plays a critical role in the physical stability of the dispersed drug as it can increase molecular mobility of drug in ASD by decreasing the glass transition temperatures (T_g) of the drug-polymer system, leading to drug crystallization. The present report describes Part III of a systematic investigation of moisture sorption by different polymers used in ASDs, where the results for four chemically different methacrylic acid-methyl methacrylate and related copolymers, namely, Eudragit® EPO, Eudragit® L100-55, Eudragit® L100, and Eudragit® S100, as the function of relative humidity (RH) are presented. Effects of moisture sorption on T_g of the polymers were also determined. Among the polymers, Eudragit® EPO is the least hygroscopic, having absorbed, for example, 1.3% w/w moisture at 25 °C/60% RH, while the three other polymers absorbed 4.7-7.5% w/w moisture at the same condition. The moisture sorption was relatively lower at 40 °C than that at 25 °C. The apparent T_g of polymers decreased with the increase in moisture content; however, T_g values remained higher than the usual storage temperature of ASD (25 °C) even at high RH, indicating that the effect of moisture sorption on the physical stability of ASD could be minimal when these polymers are used in ASDs.

Pharmacokinetic control on the release of antimicrobial drugs from pH-responsive electrospun wound dressings

The acidic pH of healthy skin changes during wound healing due to the exposure of the inner dermal and subcutaneous tissue and due to the potential colonization of pathogenic bacteria. In chronic non-healing wounds, the pH values vary in a wide pH range but the appearance of an alkaline shift is common. After a wound is incurred, neutral pH in the wound bed is characteristic of the activation of the cascade of regenerative and remodeling processes. In order to adjust drug release to the specific pH of the wound, herein, drug-loaded wound dressings having pH-responsiveness containing antiseptics and antibiotics and exerting different release kinetics in order to have a perfect match between the drug release kinetics, and the pH conditions of each wound type, were developed. We have fabricated drug-loaded electrospun nanofibers loaded with the antiseptic chlorhexidine, with the broad-spectrum antibiotic rifampicin, and with the antimicrobial of natural origin thymol, using the pH-dependent methacrylic acid copolymer Eudragit® L100-55, which dissolves at pH > 5.5; those drugs were loaded within Eudragit® S100, which dissolves at pH > 7 and, finally, within the methacrylic ester copolymer Eudragit® RS100 which is pH independent and slowly erodes and releases its contained cargo. The antibacterial action of those advanced wound dressings has been evaluated against methicillin-sensitive S. aureus Newman strain expressing the coral green fluorescent protein (cGFP), as a model of a Gram-positive bacteria, and against E. coli S17 strain as a model of a Gram-negative bacteria. It was demonstrated that those combinational products integrate in one device the required characteristics for a wound dressing with the therapeutic action of a contained active principle and can be selected depending on the wound acidic or alkaline status for its appropriated management.

Design and Evaluation of pH-Sensitive Nanoformulation of Bergenin Isolated from Bergenia ciliata

The aim of the current study is extraction and isolation of bergenin from Bergenia ciliata and fabrication of pH-sensitive Eudragit^® L100 (EL100) polymeric nanoparticles (NP) to tackle limitations of solubility. Bergenin-loaded EL100 nanoparticles (BN-NP) were fabricated via nanoprecipitation and an experimental design was conducted for optimization. A reverse phase-high performance liquid chromatography (RP-HPLC) method was developed for the quantitation of bergenin. The optimized nanoformulation was characterized by its particle size, morphology, loading capacity, entrapment efficiency, drug-excipient interaction and crystallinity. An in vitro assay was executed to gauge the release potential of pH-sensitive nanoformulation. The mean particle size, zeta potential and polydispersity index (PDI) of the optimized nanoparticles were observed to be 86.17 ± 2.1 nm, -32.33 ± 5.53 mV and 0.30 ± 0.03, respectively. The morphological analysis confirmed the spherical nature of the nanoparticles. Drug loading capacity and entrapment efficiency were calculated to be 16 ± 0.34% and 84 ± 1.3%, respectively. Fourier transform infrared spectroscopy (FTIR) studies unfolded that no interaction was present between the drug and the excipients in the nanoformulation. Crystallography studies revealed that the crystalline nature of bergenin was changed to amorphous and the nanoformulation was stable for up to 3 months at 40 °C. The present study confirms that bergenin isolation can be scaled up from abundantly growing B. ciliata. Moreover, it could also be delivered by entrapment in stimuli-responsive polymer, preventing the loss of drug in healthy tissues.

Gastrointestinal Dynamics of Non-Encapsulated and Microencapsulated Salmonella Bacteriophages in Broiler Production

Simple Summary

Bacteriophages are viruses that kill targeted bacteria and could be used as a therapy against multidrug-resistant bacteria in animal production. Gastrointestinal tract conditions throughout the broiler production cycle might compromise the efficacy of bacteriophage oral administration against Salmonella. Microencapsulation of phages could protect and prevent the premature release of the bacteriophage, thereby allowing targeted delivery to the colonization site of Salmonella, the caecum. This study was designed to assess the optimal timing of the phage intervention over a 42-day production cycle and to compare microencapsulated (delivered in animal feed) and non-encapsulated phages (delivered through the drinking water) delivery along the gastrointestinal tract. Results of this study suggest that microencapsulation of the phages in a Eudragit^® L100 pH-responsive formulation allowed targeted delivery of the phage to the chicken caecum. Microencapsulation of phages administered orally through animal feed could be a promising method to control Salmonella in the field at any time during the animal rearing period.

Abstract

Bacteriophage therapy is being considered as a promising tool to control Salmonella in poultry. Nevertheless, changes in gastrointestinal tract environmental conditions throughout the production cycle could compromise the efficacy of phages administered orally. The main objectives of this study were to assess the optimal timing of the phage administration over a 42-day production cycle and to compare microencapsulated and non-encapsulated phages and the spatial and temporal dynamics of the phage delivery along the gastrointestinal tract. Phage FGS011 was encapsulated in the pH-responsive polymer Eudragit^® L100 using the process of spray drying. At different weeks of the chicken rearing period, 15 broilers were divided into three groups. Over a period of 24 h, group 1 received non-encapsulated phages (delivered through drinking water), group 2 received microencapsulated phages (incorporated in animal feed), and group 3 did not receive any phages. Microencapsulation was shown to enable efficient delivery of the bacteriophages to the animal gut and cecum throughout the animal rearing period. During the six weeks of application, the crop displayed the highest phage concentration for both phage delivery methods. The L100 based encapsulation offered significant protection to the phages from the harsh environmental conditions in the PV-Gizzard (not seen with phages administered in drinking water) which may help in the delivery of high phage doses to the cecum. Future Salmonella challenge studies are necessary to demonstrate the benefits of microencapsulation of phages using L100 formulation on phage therapy in field studies during the rearing period.

Study of antimycobacterial, cytotoxic, and mutagenic potential of polymeric nanoparticles of copper (II) complex

This study aimed to encapsulate and characterize a potential anti-tuberculosis copper complex (CuCl₂(INH)₂.H₂O:I1) into polymeric nanoparticles (PNs) of polymethacrylate copolymers (Eudragit®, Eu) developed by nanoprecipitation method. NE30D, S100 and, E100 polymers were tested. The physicochemical characterizations were performed by DLS, TEM, FTIR, encapsulation efficiency and, in vitro release studies. Encapsulation of I1 in PN-NE30D, PN-E100, and PN-S100 was 26.3%, 94.5%, 22.6%, respectively. The particle size and zeta potential were 82.3 nm and -24.5 mV for PNs-NE30D, 304.4 nm and +18.7 mV for PNs-E100, and 517.9 nm and -6.9 mV for PNs-S100, respectively. All PDIs were under 0.5. The formulations showed a I1 controlled release at alkaline pH with 29.7% from PNs-NE30D, 7.9% from PNs-E100 and, 28.1% from PNs-S100 at 1 h incubation. PNs were stable for at least 3 months. Particularly, PNs-NE30D demonstrated moderate inhibition of M. tuberculosis and low cytotoxic activity. None of the PNs induced mutagenicity.

Sustainable Stabilizer-Free Nanoparticle Formulations of Valsartan Using Eudragit® RLPO

The bioavailability of the antihypertensive drug valsartan can be enhanced by various microencapsulation methods. In the present investigation, valsartan-loaded polymeric nanoparticles were manufactured from Eudragit® RLPO using an emulsion-solvent evaporation method. Polyvinyl alcohol (PVA) was found to be a suitable stabilizer for the nanoparticles, resulting in a monodisperse colloid system ranging in size between 148 nm and 162 nm. Additionally, a high encapsulation efficiency (96.4%) was observed. However, due to the quaternary ammonium groups of Eudragit® RLPO, the stabilization of the dispersion could be achieved in the absence of PVA as well. The nanoparticles were reduced in size (by 22%) and exhibited similar encapsulation efficiencies (96.4%). This more cost-effective and sustainable production method reduces the use of excipients and their expected emission into the environment. The drug release from valsartan-loaded nanoparticles was evaluated in a two-stage biorelevant dissolution set-up, leading to the rapid dissolution of valsartan in a simulated intestinal medium. In silico simulations using a model validated previously indicate a potential dose reduction of 60-70% compared to existing drug products. This further reduces the expected emission of the ecotoxic compound into the environment.

3D printing and enteric coating of a hollow capsular device with controlled drug release characteristics prepared using extruded Eudragit® filaments

This work focuses on the extrusion of a brittle, tacky, cationic copolymer i.e. Eudragit® E-100 to prepare filament and subsequent 3D printing of hollow capsular device using the extruded filament. An optimum amount of talc and triethyl citrate was used for the possible extrusion of the polymer. There was no thermal and chemical degradation of the polymer observed after extrusion confirmed by DSC and FTIR analysis. Microscopic analysis of the printed capsule showed the layer-by-layer manner of 3D printing. Capsule parts were printed according to the set dimensions (00 size) with minimal deviation. Printed capsule showed the soluble behaviour in gastric fluid pH 1.2 where within 15 min the encapsulated drug encounters with the dissolution medium and almost 70% drug was dissolved within 4 hr. In case of phosphate buffer pH 6.8, the printed capsule showed a longed swelling behaviour up to 12 hr and then gradually bursting of capsule occurred wherein more than 90% encapsulated drug was dissolved within 36 hr. Enteric coating of the printed capsule showed similar behaviour in alkaline medium that observed with non-enteric capsule. This indicates the potential application of this printed capsules for both gastric and intestinal specific delayed drug delivery by a single step enteric coating process.

The effect of some acrylic polymers on dissolution of celecoxib solid dispersion formulations

OBJECTIVE

The purpose of the present study was firstly to identify the effectiveness of Eudragit® polymers (Eudragit^® RL, RS, L100-55, L100, S100 and E100) in inhibition of celecoxib precipitation from buffer solutions (pH = 6.8). Furthermore, the influence of Eudragit^® polymers on non-sink dissolution behavior of celecoxib from solid dispersions was investigated.

METHODS

Solid dispersions were prepared by the rotary evaporation method. In vitro dissolution studies, FT-IR and differential scanning calorimetry were employed to characterize the formulations.

RESULTS

The results revealed that Eudragit^® E100, L100 and S100 inhibited precipitation of celecoxib efficiently. It is understood that crystallization during the dissolution of solid dispersions could happen through crystallization from solid matrix following contact with the dissolution medium or from the supersaturated solution produced following dissolution. The supersaturated drug concentrations attained from the dissolution of Eudragit^®-celecoxib solid dispersions were almost similar, suggesting that crystallization from solid matrix did not occur readily. However, only solid dispersions containing efficient crystallization inhibitor polymers were able to maintain the supersaturated solution up to the end of the dissolution run.

CONCLUSION

Results revealed that the principal mechanism of attaining supersaturated solution of celecoxib from solid dispersions was related to crystallization inhibition from solution not from solid matrix.

Mucoadhesive and mucus-penetrating interpolyelectrolyte complexes for nose-to-brain drug delivery

Nasal administration offers a possibility of delivering drugs to the brain. In the present work, nasal drug delivery systems were designed based on cationic Eudragit® EPO (EPO) and anionic Eudragit® L100-55 (L100-55) methacrylate copolymers. Two types of nanocarriers were prepared using interpolyelectrolyte complexation between these polymers. The first type of nanoparticles was prepared by forming interpolyelectrolyte complexes between unmodified EPO and L100-55. The second type of nanoparticles was formed through the complexation between PEGylated L100-55 and EPO. For this purpose, PEGylated L100-55 was synthesized by chemical conjugation of L100-55 with O-(2-aminoethyl)polyethylene glycol. The mucoadhesive properties of these nanoparticles were evaluated ex vivo using sheep nasal mucosa. Nanoparticles based on EPO and L100-55 exhibited mucoadhesive properties towards nasal mucosa, whereas PEGylated nanoparticles were non-mucoadhesive hence displayed mucus-penetrating properties. Both types of nanoparticles were used to formulate haloperidol and their ability to deliver the drug to the brain was evaluated in rats in vivo.

In Vitro and In Vivo Gastrointestinal Survival of Non-Encapsulated and Microencapsulated Salmonella Bacteriophages: Implications for Bacteriophage Therapy in Poultry

The therapeutic use of bacteriophages is recognized as a viable method to control Salmonella. Microencapsulation of phages in oral dosage forms may protect phages from inherent challenges of the gastrointestinal tract in chickens. Therefore, the main objective of this study was to assess the survival of Salmonella BP FGS011 (non-encapsulated and microencapsulated) through the gastrointestinal tract under in vitro as well as in vivo conditions after oral administration to 1-day-old chicks. To this end, the phage FGS011 was encapsulated in two different pH-responsive formulations with polymers Eudragit^® L100, and Eudragit^® S100 using the process of spray drying. Phages encapsulated in either of the two formulations were able to survive exposure to the proventriculus-gizzard in vitro conditions whereas free phages did not. Moreover, phages formulated in polymer Eudragit^® S100 would be better suited to deliver phage to the caeca in chickens. In the in vivo assay, no statistically significant differences were observed in the phage concentrations across the gastrointestinal tract for either the free phage or the encapsulated phage given to chicks. This suggested that the pH of the proventriculus/gizzard in young chicks is not sufficiently acidic to cause differential phage titre reductions, thereby allowing free phage survival in vivo.

Microfluidic assembly of pomegranate-like hierarchical microspheres for efflux regulation in oral drug delivery

Herein, a multi-functional nano-in-micro hierarchical microsphere system is demonstrated for controlling the intestinal efflux pumps that affect the oral bioavailability of many therapeutic drugs. The hierarchical particles were generated by a co-flow microfluidic device and consisted of porous silica nanoparticles packed in Eudragit® polymeric matrix. Meropenem (MER), a last-resort antibacterial drug, was loaded into porous silica (MCM-48) with a loading capacity of 34.3 wt%. In this unique materials combination, MCM-48 enables ultrahigh loading of a hydrophilic MER, while the Eudragit® polymers not only protect MER from gastric pH but also act as an antagonist for p-glycoprotein protein efflux pumps to reduce the efflux of MER back into the gastrointestinal lumen. We investigated the in-vitro temporal MER release and bidirectional (absorptive and secretory) drug permeation model across the Caco-2 monolayer. The bioavailability of MER was significantly improved by all of the prepared formulations (i.e. increased absorptive transport and reduced secretory transport). The Eudragit® RSPO formulated MER-MCM showed the best performance with an efflux ratio (i.e. secretory transport/absorptive transport) of 0.35, which is 7.4 folds less than pure MER (2.62). Lastly, the prepared formulations were able to retain the antibacterial activity of MER against Staphylococcus aureus and Pseudomonas aeruginosa. STATEMENT OF SIGNIFICANCE: Meropenem (MER) is a last resort antibiotic used for the treatment of drug-resistant and acute infections and only available as intravenous injectable dosage due to its poor chemical and thermal stability, and ultra-poor oral bioavailability because of the efflux action of P-glycoprotein (P-gp) pumps. Multifunctional colloidal micro/nanoparticles can help to solve these issues. Herein, we designed pomegranate-like hierarchical microspheres comprised of porous silica nanoparticles and enteric Eudragit® polymers (Eudragit®S100, Eudragit®RSPO, and Eudragit®RS100) using a co-flow microfluidic device. Our formulations allow for ultrahigh loading of hydrophilic MER, protects MER from gastric pH, and also block P-gp efflux pumps for enhanced MER permeation/retention with Eudragit®RSPO - showing 13.9-folds higher permeation and 7.4-folds reduction in efflux ratio in a bi-directional Caco-2 monolayer culture system.

In vitro studies and preclinical evaluation of benznidazole microparticles in the acute Trypanosoma cruzi murine model

Chagas disease is a serious parasitic infection caused by Trypanosoma cruzi. Unfortunately, the current chemotherapeutic tools are not enough to combat the infection. The aim of this study was to evaluate the trypanocidal activity of benznidazole-loaded microparticles during the acute phase of Chagas infection in an experimental murine model. Microparticles were prepared by spray-drying using copolymers derived from esters of acrylic and methacrylic acids as carriers. Dissolution efficiency of the formulations was up to 3.80-fold greater than that of raw benznidazole. Stability assay showed no significant difference (P > 0.05) in the loading capacity of microparticles for 3 years. Cell cultures showed no visible morphological changes or destabilization of the cell membrane nor haemolysis was observed in defibrinated human blood after microparticles treatment. Mice with acute lethal infection survived 100% after 30 days of treatment with benznidazole microparticles (50 mg kg-1 day-1). Furthermore, no detectable parasite load measured by quantitative polymerase chain reaction and lower levels of T. cruzi-specific antibodies by enzyme-linked immunosorbent assay were found in those mice. A significant decrease in the inflammation of heart tissue after treatment with these microparticles was observed, in comparison with the inflammatory damage observed in both infected mice treated with raw benznidazole and untreated infected mice. Therefore, these polymeric formulations are an attractive approach to treat Chagas disease.

Expedition of Eudragit® Polymers in the Development of Novel Drug Delivery Systems

Eudragit® polymer has been widely used in film-coating for enhancing the quality of products over other materials (e.g., shellac or sugar). Eudragit® polymers are obtained synthetically from the esters of acrylic and methacrylic acid. For the last few years, they have shown immense potential in the formulations of conventional, pH-triggered, and novel drug delivery systems for incorporating a vast range of therapeutics including proteins, vitamins, hormones, vaccines, and genes. Different grades of Eudragit® have been used for designing and delivery of therapeutics at a specific site via the oral route, for instance, in stomach-specific delivery, intestinal delivery, colon-specific delivery, mucosal delivery. Further, these polymers have also shown their great aptitude in topical and ophthalmic delivery. Moreover, available literature evidences the promises of distinct Eudragit® polymers for efficient targeting of incorporated drugs to the site of interest. This review summarizes some potential researches that are being conducted by eminent scientists utilizing the distinct grades of Eudragit® polymers for efficient delivery of therapeutics at various sites of interest.

Modified release of furosemide from Eudragits® and poly(ethylene oxide)-based matrices and dry-coated tablets

Modified release of furosemide from tablet formulations is preferred by patients, because of physiological problems, acute diuresis being the most serious, compared to the forms designed for immediate release. With this in view, we aimed at achieving furosemide's longer gastric retention and waste minimization by preparing matrix and compression coated tablets incorporating different grades of Eudragit® and poly(ethylene oxide) (PEO), polyvinylpyrrolidone (PVP) and lactose monohydrate. Dissolution profiles of the new formulations were compared with that of the main stream drug Lasix®, 40 mg tablets. The results indicate that the use of Eudragit® in conjunction with either PVP or lactose monohydrate led to a slower release rate in the intestinal fluids compared to Lasix®. Moreover, furosemide release in the intestinal pH from matrix tablets and compression coated tablets was not noticeably different. Formulations incorporating PEO led to sustained release, in intestinal fluids, which depended on the molecular weight of PEO.

α-Gluco-oligosaccharide in the research and development of a polymeric material for modified drug delivery

This research aimed to analyse the influence of the incorporation of α-gluco-oligosaccharide (GOS-α) in the formation of isolated films of different combinations of polymethyl by applying physicochemical analyses such as Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), thermogravimetry (TG) and scanning electron microscopy (SEM). Polymer films were prepared by evaporation associating Eudragit® RS30D with α-GOS. FTIR results confirmed the incorporation of α-GOS. The intermolecular interaction involving carbonyl and hydroxyl groups of Eudragit® with α-GOS was not detected. By TG and DSC, it was possible to detect that there were no changes in the thermal properties between the proposed combinations and the standard film. Upon SEM analysis, the appearance of pores for the association 90:10 was evidenced. Possibly, these pores act as output ports for the drug. These results sharpen the perspective of applying this material to the coating of pharmaceutical formulations of modified drug delivery.

Development and Characterization of Eudragit®-Based Electrospun Nanofibrous Mats and Their Formulation into Nanofiber Tablets for the Modified Release of Furosemide

Furosemide, a chloride channel blocker ordinarily used as a high-ceiling or loop diuretic, is practically insoluble in water and dilute acids. Due to its acidic nature, furosemide is mostly absorbed in the stomach and in the upper small intestine. Efforts have focused on the development of sustained release systems of furosemide in order to improve the effectiveness of the drug, which exhibits poor aqueous solubility and poor permeability. Recently, electrospun nanofibrous drug delivery systems have emerged as promising alternative solid-dosage forms due to their advantages of high porosity, high surface to volume ratio, and high drug-loading efficacy. Herein, a number of nanofibrous mats composed of different types of Eudragit® polymers in various concentrations and combinations loaded with furosemide were designed, successfully electrospun, and characterized using SEM, FTIR, DSC, and TGA analyses. The nanofibrous nonwovens were formulated in nanofiber tablets and the release profile of furosemide from them was evaluated at pH 1.2 and 6.8 and compared to that of physical mixture matrix tablets of analogous composition as well as to that of a commercial formulation. It was found that the release of furosemide was compatible with the gastroretentive and slower intestinal release requirements with a well-defined absorption window, while some nanofiber formulations could act as furosemide carriers in emergency situations where a relatively fast onset of its action is required, as in the case of critically ill post-traumatic patients.

(Meth)acrylate copolymers of Eudragit® type in oral tablet technology

This review focuses on the characterization of (meth)acrylate copolymers - Eudragit®, describing their thermal treatment behaviour, possible interactions between cationic and anionic polymers, incompatibilities related to Eudragits® and their use in the pharmaceutical technology of oral tablets. In summary, Eudragit® copolymers are divided into soluble ones, insoluble ones and a combination of these two types. The combination of soluble and insoluble poly(meth)acrylate gave a new type of polymer, Eudragit® FL. In oral tablet technology, Eudragits® are widely used in matrix tablets, either alone or in combination, where they mainly provide sustained drug release. To a lesser extent, Eudragits® are used in gastroretentive systems. Moreover, Eudragits® are also of great importance in coated tablets technology, where these enteric polymers provide specific drug targeting to certain parts of the digestive tract, mainly to the small intestine or colon. Important systems such as CODESTM and MMX® technology are mentioned. Last but not least an overview table of currently available oral medicinal products on the Czech market, where at least one of the Eudragits® was used as a film-forming agent, is included.

Multi-kinetic release of benznidazole-loaded multiparticulate drug delivery systems based on polymethacrylate interpolyelectrolyte complexes

Interpolyelectrolyte complexes (IPEC) formulated as multiparticulate drug delivery systems (MDDS) are interesting carriers to improve drug' performance. Benznidazole (BZ) is the first-line drug for Chagas treatment; however, it presents side effects and toxicity, conditioning its efficacy and safety. The goal of this work was to obtain novel MDDS composed by IPEC based on different polymethacrylate carriers loaded with BZ and to investigate in vitro drug delivery performance for oral administration. Physicochemical characterizations were studied and preclinical studies in a murine model of acute Chagas disease were also performed. The MDDS composed by BZ-loaded IPEC based on polymethacrylates were obtained by casting solvent followed by wet granulation methods with yields >83%. FT-IR demonstrated ionic interaction between the polyelectrolytes. Confocal microscopy, DSC and PXRD revealed a fraction uniformly distributed of free BZ on the multiparticles. The rheological evaluation of the MDDS showed adequate flow features for their formulation in hard gelatin-capsules. The type and composition of IPEC conditioned the modulation of BZ release and fluid uptake results. MDDS based on more hydrophylic Eudragit® showed very fast dissolution (Q_15min > 85%), while an extended release (Q_120min ≤ 40%) for the hydrophobic ones was observed. Capsules containing a combination of two MDDS with different release profile of BZ showed promising properties to improve Chagas disease pharmacotherapy in the preliminary in vivo assay performed, in which the BZ-loaded MDDS exhibited efficacy to reduce parasitemia, while decreasing the levels of liver injury markers in comparison to BZ conventional treatment. Multi-kinetic BZ delivery systems developed are interesting pharmaceutical alternatives to improve the treatment of Chagas disease.

Formulation of sitagliptin-loaded oral polymeric nano scaffold: process parameters evaluation and enhanced anti-diabetic performance

PURPOSE

The aim of the study to formulate and statistically optimize sitagliptin-loaded eudragit nanoparticles (SIT-NPs) and evaluate the in-vitro pharmaceutical quality and in-vivo anti-diabetic assessment.

METHOD

SIT-NPs were prepared by using combination method of solvent evaporation and nano-precipitation techniques. The influence of different independent variables as eudragit RL100 concentration (%), tween 80 concentration (%) and sonication time (min) were evaluated on dependent variables like particle size (nm), drug loading (%) and in-vitro drug release (%). Further, the optimized formulation was evaluated for surface morphology, CLSM, ex-vivo permeation study and in-vivo anti-diabetic activity and stability study.

RESULTS

The developed SIT-NPs formulations showed particle size range (135.86-193.45 nm), drug loading (6.36-8.76%) and prolonged drug release over 24 h. The prepared SIT-NPs were found to be nearly spherical with smooth surface. The comparative in-vitro release study and CLSM study results revealed that SIT-NPopt showed significantly (p < .05) enhanced release and permeation as compared to SIT free solution (SIT-Fs). The in-vivo anti-diabetic assessment revealed that SIT-NPopt able to reduce the blood sugar level (BSL) for a prolonged period of time. Further, the stability study data showed the formulations were found stable at both temperature and having the shelf life of 488 d.

CONCLUSIONS

This research has shown that SIT-NPs based on experimental design offers a new and better approach to delivering SIT, thus encouraging further development of this formulation.

Fabrication and evaluation of Eudragit® polymeric films for transdermal delivery of piroxicam

The aims of this work were to develop and characterize the prolonged release piroxicam transdermal patch as a prototype to substitute oral formulations, to reduce side effects and improve patient compliance. The patches were composed of film formers (Eudragit^®) as a matrix backbone, with PVC as a backing membrane and PEG200 used as a plasticizer. Results from X-ray diffraction patterns and Fourier transform-infrared spectroscopy indicated that loading piroxicam into films changed the drug crystallinity from needle to an amorphous or dissolved form. Piroxicam films were prepared using Eudragit^® RL100 and Eudragit^® RS100 as film formers at various ratios from 1:0 to 1:3. Films prepared solely by Eudragit^® RL100 showed the toughest and softest film, while other formulations containing Eudragit^® RS100 were hard and brittle. Drug release kinetic data from the films fitted with the Higuchi model, and the piroxicam release mechanism was diffusion controlled. Among all formulation tested, Eudragit^® RL100 films showed the highest drug release rate and the highest drug permeation flux across human epidermal membrane. Increasing drug loading led to an increase in drug release rate. Eudragit^® can be used as a film former for the fabrication of piroxicam films.

Process Analytical Quality Control of Tailored Drug Release Formulation Prepared via Hot-Melt Extrusion Technology

The objective of the present study was to compare the influence of Eudragit^® RS PO and RL PO blends on the release of water-soluble and insoluble drugs from hot-melt extruded formulations. In addition, we aimed to evaluate drug content uniformity and distribution by Fourier transform-infrared (FT-IR) chemical imaging. Theophylline (TP) and carbamazepine (CBZ) were selected as the water-soluble and insoluble model drugs, respectively. Eudragit^® RS PO and RL PO were selected as the polymeric matrices. FT-IR chemical imaging clearly demonstrated the content uniformity and distribution for both drugs in the extrudates, which was confirmed by HPLC. Increasing the ratio of Eudragit^® RL PO led to an increase in the in vitro drug release, whereas an increase in the ratio of Eudragit^® RS PO sustained the drug release for up to 12 h. The hot-melt extrusion of TP and CBZ with varying ratios of Eudragit^® RS PO and RL PO can be employed to tailor the drug release profiles. In this study, we demonstrated, for the first time, the use of FT-IR chemical imaging as a process analytical technique to determine the drug content uniformity and distribution. Our data correlated well with the results of HPLC analysis in the study of tailored drug release from the prepared hot-melt extruded formulation.

Improvement of Oral Bioavailability of Curcumin upon Microencapsulation with Methacrylic Copolymers

Curcumin (diferuloymethane; CUR) is a yellow pigment used in traditional medicine throughout history for its anti-inflammatory activity. In the last years, the scientific research has demonstrated that CUR effects are related to the modulation of crucial molecular targets, related to several pathologies including cancer, arthritis, diabetes, Crohn’s disease. In this paper, two formulations of microencapsulated CUR obtained by coevaporation with polymethacrylate polymers (Eudragit^® Retard) were investigated in vitro, ex vivo, and in vivo, and results were compared by laser confocal microscopy analysis. The permeation of microencapsulated CUR through CaCo-2 monolayers was evaluated in vitro. The mucoadhesion and bioadhesion of the CUR-loaded microparticles were evaluated in vitro, using E12 and CaCo-2 human intestinal cells, and ex vivo, by means of excised rat intestinal mucosa. After oral administration to rats, microencapsulated CUR showed a sevenfold increase of bioavailability in respect to the neat drug, with a concomitant reduction of the T_max and a five-fold plasma concentration peak increase.

Development of oral site-specific pellets containing flavonoid extract with antioxidant activity

Herbal medicines are recognized as an effective treatment of common diseases, mainly associated with oxidative stress. Therefore developing drug delivery systems of these biological active ingredients are gaining interest. Parsley (Petroselinum crispum L.) is a well-known culinary herb and its leaf contains high amount of apigenin, therefore it is suitable as a natural source of this flavonoid. Apigenin possess many health effects such as antioxidant, anti-inflammatory and anticancer activities. Unfortunately, these benefits are limited due to the low water solubility and bioavailability, it was recently classified as BCS II group compound. Therefore the aim of this study was to develop a carrier system for Petroselinum crispum extract, containing high amount of apigenin. Microcrystalline cellulose inert pellet cores were chosen and enteric coatings were applied. The produced multiparticulates had spherical shape, narrow size distribution and low moisture content. 10% (w/w) Eudragit® L 30 D-55 and 15% (w/w) Eudragit® FS 30 D coating was adequate for the modified release in vitro. The layered pellets demonstrated antioxidant activity. It was concluded that development of oral site-specific pellets containing flavonoid extract successful and the therapeutic effectiveness could be hypothesized.

Oral buccoadhesive films of ondansetron: Development and evaluation

Introduction:

Difficulty or inability in swallowing tablets/capsules during or after chemotherapy is common due to chemotherapy induced nausea and vomiting in patients. Buccoadhesive films of ondansetron hydrochloride were prepared for the prevention and treatment of chemotherapy-induced emesis. Films of varying polymeric composition were prepared in order to facilitate initial as well as prolonged drug release that could take care of acute as well as delayed emesis.

Materials and Methods:

Mucoadhesive films were prepared using polymers such as hydroxypropyl methylcellulose (HPMC) E5, HPMC K100, and Eudragit^® NE 30 D. The effect of concentration of these polymers on physical properties and drug release were studied. All the films were prepared by solvent casting method. In another part of the study, the effect of drug concentration on physical and mucoadhesive properties of film were assessed, keeping the polymer concentration fixed.

Results:

Films containing HPMC showed good mucoadhesion. Increasing the concentration of Eudragit^® NE 30 D in the films retarded drug release and increased residence time, however, reduced mucoadhesion. At a fixed polymer concentration and ratio, films prepared using an increased drug content showed an increased mucoadhesion.

Conclusion:

Films prepared using HPMC E5 (1000 mg), HPMC K100 (500 mg), and Eudragit^® NE 30 D (750 mg) provided initial rapid followed by sustained drug release over a period of 6 h. Given the promising results, the study concluded that the developed buccal films have the potential to release ondansetron required for chemotherapy induced acute and delayed emesis.

Effects of spray drying conditions on the physicochemical properties of the Tramadol-Hcl microparticles containing Eudragit(®) RS and RL

The preparation of Tramadol-HCL spray-dried microspheres can be affected by the long drug recrystallization time. Polymer type and drug–polymer ratio as well as manufacturing parameters affect the preparation. The purpose of this work was to evaluate the possibility to obtain tramadol spray-dried microspheres using the Eudragit^® RS and RL; the influence of the spray-drying parameters on morphology, dimension, and physical stability of microspheres was studied. The effects of matrix composition on microparticle properties were characterized by Laser Light scattering, differential scanning calorimetry (DSC), X-ray diffraction study, FT-infrared and UV-visible spectroscopy. The spray-dried microparticles were evaluated in terms of shape (SEM), size distribution (Laser light scattering method), production yield, drug content, initial drug loding and encapsulation efficiency. The results of X-ray diffraction and thermal analysis reveals the conversion of crystalline drug to amorphous. FTIR analysis confirmed the absence of any drug polymer interaction. The results indicated that the entrapment efficiency (EE), and product yield were depended on polymeric composition and polymeric ratios of the microspheres prepared. Tramadol microspheres based on Eudragit^® blend can be prepared by spray-drying and the nebulization parameters do not influence significantly on particle properties.