Formulation and in vitro evaluation of Eudragit S-100 coated naproxen matrix tablets for colon-targeted drug delivery system

Advanced 3D Electrospinning "Xspin" System: Fabrication of Bifiber Floating Oral Pharmaceutical Scaffolds for Controlled Drug Delivery

Electrospinning has become a widely used and efficient method for manufacturing nanofibers from diverse polymers. This study introduces an advanced electrospinning technique, Xspin - a multi-functional 3D printing platform coupled with electrospinning system, integrating a customised 3D printhead, MaGIC - Multi-channeled and Guided Inner Controlling printheads. The Xspin system represents a cutting-edge fusion of electrospinning and 3D printing technologies within the realm of pharmaceutical sciences and biomaterials. This innovative platform excels in the production of novel fiber with various materials and allows for the creation of highly customized fiber structures, a capability hitherto unattainable through conventional electrospinning methodologies. By integrating the benefits of electrospinning with the precision of 3D printing, the Xspin system offers enhanced control over the scaffold morphology and drug release kinetics. Herein, we fabricated a model floating pharmaceutical dosage for the dual delivery of curcumin and ritonavir and thoroughly characterized the product. Fourier transform infrared (FTIR) spectroscopy demonstrated that curcumin chemically reacted with the polymer during the Xspin process. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) confirmed the solid-state properties of the active pharmaceutical ingredient after Xspin processing. Scanning electron microscopy (SEM) revealed the surface morphology of the Xspin-produced fibers, confirming the presence of the bifiber structure. To optimize the quality and diameter control of the electrospun fibers, a design of experiment (DoE) approach based on quality by design (QbD) principles was utilized. The bifibers expanded to approximately 10-11 times their original size after freeze-drying and effectively entrapped 87% curcumin and 84% ritonavir. In vitro release studies demonstrated that the Xspin system released 35% more ritonavir than traditional pharmaceutical pills in 2 h, with curcumin showing complete release in pH 1.2 in 5 min, simulating stomach media. Furthermore, the absorption rate of curcumin was controlled by the characteristics of the linked polymer, which enables both drugs to be absorbed at the desired time. Additionally, multivariate statistical analyses (ANOVA, pareto chart, etc.) were conducted to gain better insights and understanding of the results such as discern statistical differences among the studied groups. Overall, the Xspin system shows significant potential for manufacturing nanofiber pharmaceutical dosages with precise drug release capabilities, offering new opportunities for controlled drug delivery applications.

Co-emulsified Alginate-Eudragit Nanoparticles: Potential Carriers for Localized and Time-defined Release of Tenofovir in the Female Genital Tract

This research aimed to explore the possibilities of Eudragit S100 (ES100) and sodium alginate as carriers for tenofovir disoproxil fumarate (TDF) in the female genital tract. Alginate and alginate-ES100 nanoparticles were prepared using the ionic gelation and emulsion/gelation complexation method, respectively. The nanocarriers were tested using morphological, physicochemical, in vitro drug release, and cytotoxicity analyses. In SEM and TEM images, the presence of spherical and uniformly distributed nanoparticles was revealed. The FTIR spectrum showed that alginate and calcium chloride interacted due to ionic bonds linking divalent calcium ions and the -COO- of alginate groups. Alginate and ES100 interacted via the ester C=O amide stretching. The results obtained from XRD and DSC, on the other hand, revealed a favorable interaction between sodium alginate and ES100 polymers, as evidenced by the crystallization peaks observed. Under experimental design analysis and optimization, overall size distribution profiles ranged from 134.9 to 228.0 nm, while zeta potential results showed stable nanoparticles (-17.8 to -38.4 MV). The optimal formulation exhibited a maximum cumulative in vitro release of 72% (pH 4.2) up to 96 h. The cytotoxicity tests revealed the safety of TDF-loaded nanoparticles on vaginal epithelial cells at concentrations of 0.025 mg/mL, 0.5 mg/mL, and 1 mg/mL for 72 h. These results indicated that alginate-ES100 nanoparticles have the potential to preserve and sustain the release of the TDF drug in the FGT. The future goal is to develop a low-dose non-toxic microbicide that can be administered long term in the vagina to cater to both pregnant and non-pregnant HIV patients.

Fabrication and Synthesis of Thiococlchicoside Loaded Matrix Type Transdermal Patch

BACKGROUND

The goal of this work was to synthesize and fabricate matrix type transdermal patches based on a combination of polymers (Eudragit L100, HPMC and PVP K30), plasticizer and crosslinking agents (propylene glycol and triethyl citrate) and adhesives (Dura Tak 87-6908) to increase Thiocolchicoside (THC) absorption via topical route. This method allows avoidance of first-pass metabolism along with a consistent and extended duration of therapeutic activity.

METHODS

Fabrication and casting of polymeric solutions containing THC was done either in petri plates or through lab coater to get transdermal patches. Finally, the formulated patches were studied for their physicochemical and biological evaluation using scanning electron microscopy, FTIR, DSC, XRD and ex-vivo permeation studies using pig ear skin.

RESULTS

FTIR studies confirm that the THC characteristics peaks (carbonyl (Amide I) at 1525.5 cm-1, C=O stretching (tropane ring) at 1664.4 cm-1, Amide II band (N-H stretching) at 3325.9 cm-1, thioether band at 2360.7 cm-1, and OH group stretching band at 3400.2 cm-1) are still present in the polymer mixture even after formulation as a transdermal patch, indicating compatibility among all excipients. While on the other hand, DSC studies confirm endothermic peaks for all the polymers along with THC with the highest enthalpy of 65.979 J/g, which is an indicator of sharp endothermic peak at 198°C, leading to the melting of THC. The percentage drug content and percentage moisture uptake of all the formulation was found in the range of 96 ± 2.04 to 98.56 ± 1.34% and 4.13 ± 1.16 to 8.23 ± 0.90%, respectively. Drug release and release kinetics studies confirm that it is dependent on the composition of individual formulation.

CONCLUSION

All these findings support the possibility of using suitable polymeric composition, as well as proper formulation and manufacturing circumstances, to create a one-of-a-kind technology platform for transdermal drug administration.

Optimization, cellular uptake, and in vivo evaluation of Eudragit S100-coated bile salt-containing liposomes for oral colonic delivery of 5-aminosalicylic acid

Eudragit S100-coated bile salt-containing liposomes were prepared and optimized by experimenting with different variables, including bile salt type and concentration, and the method of incorporation into liposomes using a model hydrophilic compound, 5-aminosalicylic acid (5-ASA). After optimizing the formulation, cellular uptake, and animal pharmacokinetic experiments were performed. The inclusion of sodium glycocholate (SG) into liposomes decreased liposome particle size and entrapment efficiency significantly but had no effect on zeta potential. The method of incorporating SG into the lipid or aqueous phase of the liposome did not notably impact the characteristics of the liposomes but the hydration media had a substantial effect on the entrapment efficiency of 5-ASA. In vitro drug release in different fluids simulating distinct gastrointestinal tract sections, indicated pH-dependent disintegration of the coating layer of coated SG-containing liposomes. The majority of the drug was retained when subjected to simulated gastric fluid (SGF) and fed-state simulated intestinal fluid (FeSSIF) (≈ 37% release after 2 h in SGF pH 1.2, followed by 3 h in FeSSIF pH 5). The remaining drug was subsequently released in phosphate-buffered saline pH 7.4 (≈ 85% release within 24 h). Increasing SG concentration in the liposomes decreased the amount of drug released in FeSSIF. Similar results were observed when SG was replaced with sodium taurocholate. Cellular uptake studies in Caco-2 cells demonstrated that all liposomal formulations (conventional liposomes, bile salt-containing liposomes, and coated bile salt-containing liposomes) have shown to be equally effective at increasing the cellular uptake compared to free fluorescein solution. In the pharmacokinetic study, coated bile salt-containing liposomes showed a lower Cmax and prolonged residence in the gastrointestinal tract in comparison to conventional liposomes. Taken together, these findings suggest that the polymer-coated bile salt-containing liposomes have the potential to serve as a drug delivery system targeted at the colon.

Achillea wilhelmsii-Incorporated Chitosan@Eudragit Nanoparticles Intended for Enhanced Ulcerative Colitis Treatment

Achillea wilhelmsii (A. wilhelmsii) contains several therapeutic phytochemicals, proposing a protective effect on inflammatory responses in autoimmune diseases such as ulcerative colitis (UC). However, its activities against UC encounter multiple obstacles. The current study aimed to formulate a colon-specific delivery of A. wilhelmsii for treating UC using chitosan nanoparticles (NPs) and Eudragit S100 as a mucoadhesive and pH-sensitive polymer, respectively. Core chitosan NP was loaded with A. wilhelmsii extract, followed by coating with Eudragit S100. Then, physicochemical characterizations of prepared NPs were conducted, and the anti-UC activity in the rat model was evaluated. The relevant physicochemical characterizations indicated the spherical NPs with an average particle size of 305 ± 34 nm and high encapsulation efficiency (88.6 ± ‏7.3%). The FTIR (Fourier transform infrared) analysis revealed the Eudragit coating and the extract loading, as well as the high radical scavenging ability of A. wilhelmsii was confirmed. The loaded NPs prevented the extract release in an acidic pH-mimicking medium and presented a complete release thereafter at a colonic pH. The loaded NPs markedly mitigated the induced UC lesions in rats, reflected by reducing inflammation, ulcer severity, and UC-related symptoms. Further, histopathological analysis exhibited reducing the extent of the inflammation and damage to colon tissue, and the determination of the involved pro-inflammatory cytokines in serum showed a significant reduction relative to free extract. The present results show that chitosan NPs containing A. wilhelmsii extract coated with Eudragit having proper physicochemical properties and substantial anti-inflammatory activity can significantly improve colonic lesions caused by UC.

A collagen-based theranostic wound dressing with visual, long-lasting infection detection capability

Continuous wound monitoring is one strategy to minimise infection severity and inform prompt variations in therapeutic care following infection diagnosis. However, integration of this functionality in therapeutic wound dressings is still challenging. We hypothesised that a theranostic dressing could be realised by integrating a collagen-based wound contact layer with previously demonstrated wound healing capability, and a halochromic dye, i.e. bromothymol blue (BTB), undergoing colour change following infection-associated pH changes (pH: 5-6 ➔ >7). Two different BTB integration strategies, i.e. electrospinning and drop-casting, were pursued to introduce long-lasting visual infection detection capability through retention of BTB within the dressing. Both systems had an average BTB loading efficiency of 99 wt% and displayed a colour change within 1 min of contact with simulated wound fluid. Drop-cast samples retained up to 85 wt% of BTB after 96 h in a near-infected wound environment, in contrast to the fibre-bearing prototypes, which released over 80 wt% of BTB over the same time period. An increase in collagen denaturation temperature (DSC) and red shifts (ATR-FTIR) suggest the formation of secondary interactions between the collagen-based hydrogel and the BTB, which are attributed to count for the long-lasting dye confinement and durable dressing colour change. Given the high L929 fibroblast viability in drop-cast sample extracts (92 %, 7 days), the presented multiscale design is simple, cell- and regulatory-friendly, and compliant with industrial scale-up. This design, therefore, offers a new platform for the development of theranostic dressings enabling accelerated wound healing and prompt infection diagnosis.

Colon specific delivery of miR-155 inhibitor alleviates estrogen deficiency related phenotype via microbiota remodeling

Compelling data have indicated menopause-associated increase in cardiovascular disease in women, while the underlying mechanisms remain largely unknown. It is established that changes of intestinal microbiota affect cardiovascular function in the context of metabolic syndrome. We here aimed to explore the possible link between host intestinal function, microbiota, and cardiac function in the ovariectomy (OVX) mouse model. Mice were ovariectomized to induce estrogen-related metabolic syndrome and cardiovascular defect. Microbiota was analyzed by 16s rRNA sequencing. miRNA and mRNA candidates expression were tested by qPCR. Cardiac function was examined by echocardiography. Colon specific delivery of miRNA candidates was achieved by oral gavage of Eudragit S100 functionalized microspheres. In comparison with the sham-operated group, OVX mice showed compromised cardiac function, together with activated inflammation in the visceral adipose tissue and heart. Lactobacillus abundance was significantly decreased in the gut of OVX mice. Meanwhile, miR-155 was mostly upregulated in the intestinal epithelium and thus the feces over other candidates, which in turn decreased Lactobacillus abundance in the intestine when endocytosed. Oral delivery of miR-155 antagonist restored the protective microbiota and thus protected the cardiac function in the OVX mice. This study has established a possible regulatory axis of intestinal miRNAs-microbiota-estrogen deficiency related phenotype in the OVX model. Colon specific delivery of therapeutic miRNAs would possibly restore the microbiota toward protective phenotype in the context of metabolic syndrome.

Formulation, Characterization, and Evaluation of Eudragit-Coated Saxagliptin Nanoparticles Using 3 Factorial Design Modules

Background and Introduction: Saxagliptin is a hypoglycemic drug that acts as a dipeptidyl peptidase-4 (DPP-4) inhibitor and is preferably used in the treatment of Type 2 Diabetes Mellitus (T2DM). It is safe and tolerable; however, the major disadvantage associated with it is its low bioavailability. Aim: The present research aimed to enhance the bioavailability of the drug by enteric coating with a polymer that controls the rate of drug delivery, and it was prepared as Solid Lipid Nanoparticles (SLNs). Methodology: In the current study, various SLN formulations were developed using a central composite design (CCD) module using Design Expert-11 software. A modified solvent injection technique was used to prepare Saxagliptin nanoparticles coated with Eudragit RS100. The CCD was used to determine the independent variables and their effect on dependent variables at varied levels. Evaluation studies such as particle size analysis, Zeta potential, polydispersity index (PDI), drug loading, entrapment efficiency, in-vitro drug release studies, and in vivo pharmacokinetic studies were performed for the optimized SLN formulation. The reversed-phase HPLC method was developed and validated for the estimation of the pharmacokinetic parameters of the pure drug and prepared SLNs. Results: The effect of independent variables (A1: amount of lipid, A2: amount of polymer, A3: surfactant concentration, and A4: homogenization speed) on dependent variables (R1: particle size, and R2: entrapment efficiency) was established in great detail. Observed responses of the prepared and optimized Saxagliptin SLN were close to the predicted values by the CCD. The prepared SLNs depicted particle sizes in the range of 212–442 nm. The particle size analysis results showed that an increase in the lipid concentration led to an increase in particle size. The developed bioanalytical method was noted to be very specific and robust. The method accuracy varied from 99.16% to 101.95% for intraday, and 96.08% to 103.12% for inter day operation at low (5 mcg/mL), moderate (10 mcg/mL), and higher (15 mcg/mL) drug concentrations. The observed Zeta potential values for the prepared SLNs were in the range of −41.09 ± 0.11 to 30.86 ± 0.63 mV suggesting quite good stability of the SLNs without any aggregation. Moreover, the polydispersity indices were in the range of 0.26 ± 0.051 to 0.45 ± 0.017, indicative of uniformity of sizes among the prepared SLNs. In vivo study outcomes proved that Saxagliptin oral bioavailability significantly enhanced in male Albino Wistar Rats via SLN formulation and Eudragit RS100 coating approach. Conclusions: The developed and optimized Saxagliptin SLNs revealed enhanced Saxagliptin bioavailability in comparison to the native drug. Thus, this formulation strategy can be of great importance and can be implied as a promising approach to enhance the Saxagliptin bioavailability for facilitated T2DM therapy.

Structural characterization and active site prediction of keratinase from Bacillus flexus

Sixteen keratinolytic bacteria were isolated from poultry farm soil samples. The highest keratinlytic enzyme producers of Bacillus flexus was confirmed with 16S rRNA sequence analysis. It is of interest to understand the binding efficiency of the modelled keratinase from Bacillus flexus with different substrates using molecular docking studies. Data provides insights for the identification of substrate recognition patterns, and the development of suitable enzymes to improve their use in keratin degradation.

Evaluation of the therapeutic efficacy of dressings with ZnO nanoparticles in the treatment of diabetic foot ulcers

Type 2 diabetes (T2D) in developed countries have a prevalence of 11% with diabetic foot infections as the most common cause of hospitalization and amputation. To achieve healing of the diabetic foot ulcer wounds, appropriate dressings are essential and their effectiveness can be enhanced with nanoparticles, nevertheless ideal combinations of dressing composition and nanodrugs require further testing in humans. We have developed a calcium alginate dressings with ZnO nanoparticles (CAZnODs) for the treatment of diabetic foot ulcers in human patients. To test the efficacy of CAZnODs we designed a randomized controlled clinical experiment on 26 T2D patients with foot ulcers. The patients were randomized into two groups: G1 treatment with calcium alginate with NPs (G1; n = 16), and group 2 received the treatment without NPs (G2, n = 10). The bandage change was performed every 48 h The duration of the protocol was established at 10 weeks. Here, we report healing was achieved in patients, with 75% wound closure in G1 under treatment with NPs of calcium alginate versus 71% in G2 (calcium alginate without NPs) (p = 0.011). The average healing time was 48 days in G1 and 72 days in G2. Our data shows that CAZnODs were well tolerated and did not interfere with the wound healing process. The final wound area and time of healing support the hypothesis that the use of calcium alginate dressings with nanoparticles may induce better tissue regeneration while avoiding T2D complications such as secondary infections.

Multiparticulate Systems of Meloxicam for Colonic Administration in Cancer or Autoimmune Diseases

The aim of this research is the development of new colonic release systems of meloxicam (MLX) a non-steroidal anti-inflammatory drug (NSAIDs) with pH and time-dependent vehicles for cancer or autoimmune diseases. The colon has a higher pH than the rest of the gastrointestinal tract (GIT) and this can be used as a modified release strategy. Eudragit^® polymers are the most widely used synthetic products in the design of colonic release formulations because they might offer mucoadhesiveness and pH-dependent release. Colonic delivery systems produced with pH-dependent and permeable polymers (FS-30D) or with pH-independent and low permeability polymers (NM-30D), must dissolve at a pH range of 6.0–7.0 to delay the release of the drug and prevent degradation in the GIT, before reaching the colon. The conditions prepared to simulate a gastrointestinal transit showed the CNM multiparticulate system, composed of Eudragit^® NM and cellulose, as the best release option for MLX with a more sustained release with respect to the other formulations. CNM formulation followed Higuchi and First-order release kinetics, thus MLX release was controlled by a combination of diffusion and polymers swelling/eroding processes.

Risk Assessment and QbD-Based Optimization of Sorafenib Tosylate Colon Targeted Bilayer Tablet: In Vitro Characterization, In Vivo Pharmacokinetic, and In Vivo Roentgenography Studies

The employment of site-specific administration in colon is a promising technique to improve efficacy and reduce systemic side effects of anticancer medications used in colorectal cancer. However, the physiology of the gastrointestinal tract and colonic environment limit the efficient delivery of orally administered anticancer drugs to the colon. These prerequisites can be fulfilled by a release modulated colon targeted drug delivery system (CTDDS) based on pH-dependent chronotherapeutic bilayer tablet of sorafenib tosylate (ST). Quality by design (QbD) was used to examine the risk assessment. The Box-Behnken design was used to optimize the core uncoated bilayer tablet, whereas the 2² factorial design was used to optimize the coating process. The amount of croscarmellose sodium, Eudragit^® RLPO, and tablet hardness all had a significant impact on disintegration time and drug release, according to the results of the core uncoated bilayer optimization. The amount of Eudragit^® S 100 and PEG 400 in the final coated tablet had a considerable impact on drug release. The optimized formulation demonstrated 5-h lag time, a peculiar feature of CTDDS. The pharmacokinetic studies of coated tablet in rabbits showed lower C_max (4.45 ± 0.40 µg/mL) and AUC (148.52 ± 3.96 h µg/mL), whereas T_max was substantially delayed (8.0 ± 0.57 h) compared to core uncoated tablet. The tablet remained intact until it reached the colon (> 4 h), according to the in vivo roentgenography studies. The present study revealed that a QbD approach can be useful to develop a rugged and scalable CTDDS.

Preparation, Characterization and In Vitro Evaluation of Eudragit S100-Coated Bile Salt-Containing Liposomes for Oral Colonic Delivery of Budesonide

The aim of this study was to prepare a liposomal formulation of a model drug (budesonide) for colonic delivery by incorporating a bile salt (sodium glycocholate, SGC) into liposomes followed by coating with a pH-responsive polymer (Eudragit S100, ES100). The role of the SGC is to protect the liposome from the emulsifying effect of physiological bile salts, while that of ES100 is to protect the liposomes from regions of high acidity and enzymatic activity in the stomach and small intestine. Vesicles containing SGC were prepared by two preparation methods (sonication and extrusion), and then coated by ES100 (ES100-SGC-Lip). ES100-SGC-Lip showed a high entrapment efficiency (>90%) and a narrow size distribution (particle size = 275 nm, polydispersity index < 0.130). The characteristics of liposomes were highly influenced by the concentration of incorporated SGC. The lipid/polymer weight ratio, liposome charge, liposome addition, and mixing rate were critical factors for efficient and uniform coating. In vitro drug release studies in various simulated fluids indicate a pH-dependent dissolution of the coating layer, and the disintegration process of ES100-SGC-Lip was evaluated. In conclusion, the bile salt-containing ES100-coated liposomal formulation has potential for effective oral colonic drug delivery.

Site-selective oral delivery of therapeutic antibodies to the inflamed colon via a folic acid-grafted organic/inorganic hybrid nanocomposite system

This study aimed to develop a pH-responsive folic acid-grafted organic/inorganic hybrid nanocomposite system for site-selective oral delivery of therapeutic antibodies. A folic acid-grafted aminoclay (FA-AC) was prepared via an in situ sol‒gel method. Then, a drug-loaded nanocomplex was prepared via the electrostatic interaction of FA-AC with infliximab (IFX), a model antibody, and coated with Eudragit® S100 (EFA-AC-IFX). FA-AC exhibited favorable profiles as a drug carrier including low cytotoxicity, good target selectivity, and capability to form a nanocomplex with negatively charged macromolecules. A pH-responsive FA-AC-based nanocomplex containing IFX (EFA-AC-IFX) was also obtained in a narrow size distribution with high entrapment efficiency (>87%). The conformational stability of IFX entrapped in EFA-AC-IFX was well maintained in the presence of proteolytic enzymes. EFA-AC-IFX exhibited pH-dependent drug release, minimizing premature drug release in gastric conditions and the upper intestine. Accordingly, oral administration of EFA-AC-IFX to colitis-induced mice was effective in alleviating the progression of ulcerative colitis, while oral IFX solution had no efficacy. These results suggest that a pH-responsive FA-AC-based nanocomposite system can be a new platform for the site-selective oral delivery of therapeutic antibodies.

Colon targeted chitosan-melatonin nanotherapy for preclinical Inflammatory Bowel Disease

Inflammatory Bowel (IBD) is an umbrella term which includes Crohn's Disease (CD) and Ulcerative Colitis (UC). At present, therapies available for management of the UC includes, corticosteroid, immuno-suppressants and antibiotics are used for mild to moderate UC conditions which can cause nephrotoxicity, hepatotoxicity and cardiotoxicity. Hence, a novel therapeutic candidate having potent anti-inflammatory effect is urgently warranted for the management of UC. Melatonin has emerged as a potent anti-inflammatory agent. However, poor solubility limits its therapeutic potential. Therefore, colon targeted Eudragit-S-100 coated chitosan nanoparticles have been demonstrated to improve melatonin therapeutic efficacy. It was found that melatonin loaded chitosan and colon targeted chitosan nanoparticles had promising anti-inflammatory efficacy in terms of NO scavenging activity in an in-vitro LPS challenged macrophages. Also, colon targeted oral chitosan nano-formulation exhibited remarkable protection in an in vivo UC mice model by improving gross pathological parameters, histo-architectural protection, goblet cell depletion, and immune cells infiltration which can be extrapolated to clinical studies.

Preparation of stable enteric folic acid-loaded microfiber using the electrospinning method

Objectives

Folic acid is an essential vitamin, labile to hydrolysis in the acidic environment of the stomach with low water solubility and bioavailability. In order to solve these problems, enteric oral folic acid-loaded microfibers with a pH-sensitive polymer by electrospinning method were prepared.

Materials and Methods

Electrospinning was performed at different folic acid ratios and voltages. Fibers were evaluated in terms of mechanical strength, acidic resistance, and drug release. Additionally, DSC (Differential Scanning Calorimetry), FTIR (Fourier-transform infrared spectroscopy), and XRD (X-ray diffraction) analyses were performed on the optimal formulation.

Results

Drug ratio and voltage had a considerable effect on fibers' entrapment efficiency, acid resistance, and mechanical strength. Based on the obtained results, the optimum formulation containing 1.25% of the drug/polymer was prepared at 18 kV. The entrapment efficiency of the optimal sample was above 90% with an acid resistance of higher than 70%. The tensile test confirmed the high mechanical properties of the optimum microfiber. DSC and XRD tests indicated that folic acid was converted to an amorphous form in the fiber structure and the FTIR test confirmed the formation of a chemical bond between the drug and the polymer. The release of the drug from the optimal fiber was about 90% in 60 min.

Conclusion

In conclusion, the optimal formulation of folic acid with proper mechanical properties can be used as a candidate dosage form for further bioavailability investigations.

Solid Dispersions of Gefitinib Prepared by Spray Drying with Improved Mucoadhesive and Drug Dissolution Properties

Gefitinib is a tyrosine kinase inhibitor that is intended for oral administration yet suffers poor bioavailability along with undesirable side effects. To enhance its solubility and allow colon targeting, gefitinib (ZD) and blends of different ratios of polymers (ternary dispersion) were prepared in organic solution, and solid dispersions were generated employing the spray drying (SD) technique. The methylmethacrylate polymer Eudragit S 100 was incorporated for colon targeting; polyvinylpyrrolidone (PVP) and hydroxypropyl methyl cellulose (HPMC) were utilised to improve the solubility of ZD. SEM, DSC, XRPD, FT-IR, dissolution and cytotoxicity studies were undertaken to characterise and evaluate the developed formulations. SEM images revealed that the rod-shaped crystals of ZD were transformed into collapsed spheres with smaller particle size in the spray-dried particles. DSC, FTIR and XRPD studies showed that ZD loaded in the spray-dried dispersions was amorphous. ZD dissolution and release studies revealed that while a significant (P < 0.05) increase in the ZD dissolution and release was observed from HPMC-based solid dispersion at pH 7.2 (up to 95% in 15 h), practically no drug was released at pH 1.2 and pH 6.5. Furthermore, the HPMC-based solid dispersions displayed enhanced mucoadhesive properties compared with PVP-based ones. Interestingly, cell viability studies using the neutral red assay showed that PVP and HPMC-based solid dispersions had no additional inhibitory effect on Caco-2 cell line compared to the pure drug.

Nanotechnology Based Approaches in Phage Therapy: Overcoming the Pharmacological Barriers

With the emergence and spread of global antibiotic resistance and the need for searching safer alternatives, there has been resurgence in exploring the use of bacteriophages in the treatment of bacterial infections referred as phage therapy. Although modern phage therapy has come a long way as demonstrated by numerous efficacy studies but the fact remains that till date, phage therapy has not received regulatory approval for human use (except for compassionate use).Thus, to hit the clinical market, the roadblocks need to be seriously addressed and gaps mended with modern solution based technologies. Nanotechnology represents one such ideal and powerful tool for overcoming the pharmacological barriers (low stability, poor in-vivo retention, targeted delivery, neutralisation by immune system etc.) of administered phage preparations.In literature, there are many review articles on nanotechnology and bacteriophages but these are primarily focussed on highlighting the use of lytic and temperate phages in different fields of nano-medicine such as nanoprobes, nanosensors, cancer diagnostics, cancer cell targeting, drug delivery through phage receptors, phage display etc. Reviews specifically focused on the use of nanotechnology driven techniques strictly to improve phage therapy are however limited. Moreover, these review if present have primarily focussed on discussing encapsulation as a primary method for improving the stability and retention of phage(s) in the body.With new advances made in the field of nanotechnology, approaches extend from mere encapsulation to recently adopted newer strategies. The present review gives a detailed insight into the more recent strategies which include 1) use of lipid based nano-carriers (liposomes, transfersomes etc.) 2) adopting microfluidic based approach, surface modification methods to further enhance the efficiency and stability of phage loaded liposomes 3) Nano- emulsification approach with integration of microfluidics for producing multiple emulsions (suitable for phage cocktails) with unique control over size, shape and drop morphology 4) Phage loaded nanofibers produced by electro-spinning and advanced core shell nanofibers for immediate, biphasic and delayed release systems and 5) Smart release drug delivery platforms that allow superior control over dosing and phage release as and when required. All these new advances are aimed at creating a suitable housing system for therapeutic bacteriophage preparations while targeting the multiple issues of phage therapy i.e., improving phage stability and titers, improving in-vivo retention times, acting as suitable delivery systems for sustained release at target site of infection, improved penetration into biofilms and protection from immune cell attack. The present review thus aims at giving a complete insight into the recent advances (2010 onwards) related to various nanotechnology based approaches to address the issues pertaining to phage therapy. This is essential for improving the overall therapeutic index and success of phage therapy for future clinical approval.

Cationic Polymeric Nanoparticles for Improved Ocular Delivery and Antimycotic Activity of Terconazole

Terconazole (TCZ) is a broad-spectrum antifungal triazole that is particularly active against Candida species, but its poor water solubility hinders its ocular absorption and restricts its application. This study aims to fabricate TCZ-loaded cationic polymeric nanoparticles to enhance the ocular delivery and antimycotic activity of terconazole. TCZ-loaded nanoparticles were developed by nanoprecipitation method employing Eudragit RLPO®. They were characterized by entrapment efficiency (EE%), particle size (PS), zeta potential (ZP), morphology, Fourier transform infrared spectroscopy (FT-IR), and X-ray powder diffraction (XRPD). In-vitro antimycotic activity was evaluated by measuring zone of inhibition (ZI), minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC). The developed nanoparticles were spherical with moderate to high EE% (44.03-71.14%), a nanometric PS (49.41-78.72 nm), and a positively charged ZP (≥ +21.47). In-vitro release studies revealed sustained release of drug up to 24 h. FT-IR of TCZ-loaded nanoparticles revealed distinctive peaks for Eudragit RLPO® and Poloxamer-188, with disappearance of the TCZ characteristic peaks. XRPD revealed the amorphous state of TCZ within the polymer matrix. Mucoadhesive studies proved the mucoadhesive property of the developed TCZ nanoparticles. In-vitro antimycotic studies, assessed by ZI, MIC and MFC, revealed enhanced antimycotic activity of TCZ-loaded nanoparticles against Candida albicans, relative to plain TCZ. No irritation or abnormal changes to the rabbits' eyes for plain and medicated polymeric nanoparticles were found by the in-vivo Draize test. These findings reveal that the cationic polymeric nanoparticles can be regarded as a potential drug delivery system for enhancing the ocular antimycotic activity of TCZ.

Eudragit®: A Versatile Family of Polymers for Hot Melt Extrusion and 3D Printing Processes in Pharmaceutics

Eudragit® polymers are polymethacrylates highly used in pharmaceutics for the development of modified drug delivery systems. They are widely known due to their versatility with regards to chemical composition, solubility, and swelling properties. Moreover, Eudragit polymers are thermoplastic, and their use has been boosted in some production processes, such as hot melt extrusion (HME) and fused deposition modelling 3D printing, among other 3D printing techniques. Therefore, this review covers the studies using Eudragit polymers in the development of drug delivery systems produced by HME and 3D printing techniques over the last 10 years. Eudragit E has been the most used among them, mostly to formulate immediate release systems or as a taste-masker agent. On the other hand, Eudragit RS and Eudragit L100-55 have mainly been used to produce controlled and delayed release systems, respectively. The use of Eudragit polymers in these processes has frequently been devoted to producing solid dispersions and/or to prepare filaments to be 3D printed in different dosage forms. In this review, we highlight the countless possibilities offered by Eudragit polymers in HME and 3D printing, whether alone or in blends, discussing their prominence in the development of innovative modified drug release systems.

Effect of pH adjustment and ratio of oppositely charged polymers on the mechanistic performance and sustained release of volatile perfume in interpolyelectrolyte complex microcapsules

In this study, volatile perfume was encapsulated in microcapsules (MCs) via interpolyelectrolyte complexes (IPECs) of oppositely charged polymers, with high encapsulation efficiency, to be delivered in a sustained manner. Positively charged chitosan (CTS) and negatively charged Eudragit® S100 (ES100) were used as eco-friendly biopolymers. Limonene (LMN) was selected as the model perfume. First, the solution of LMN in ethyl acetate and poloxamer 407 (POX407) in acidic solution was emulsified using ultrasonication. CTS and ES100 were added in that particular order to form o/w emulsion. LMN-loaded microcapsules (LMN-MCs) were prepared by adjusting the pH and freeze-drying for solidification. The electrostatic interactions of CTS and ES100 to form IPECs were highly dependent on pH, changing in the microscopic images of emulsion droplets and zeta potential. The NH₃⁺ group of CTS and the COO^- group of ES100 caused the electrostatic interactions at a specific pH. The formation mechanism of LMN-MCs was successfully validated using instrumental analysis, charge density, and energy dispersive X-ray spectrometer (EDS) mapping. Encapsulation efficiency, loading content, and release rates of LMN-MCs varied according to the ratios of CTS and ES100, demonstrating optimal performance at a 1:1 ratio. The current LMN-MCs could provide a simple manufacturing process with high performance in terms of encapsulation efficiency (>94%), drug loading, yield and sustained release of volatile perfume for 120 h.

Enhanced Antioxidant Efficacy of Nano-Encapsulated Protorhus Longifolia Methanol Extract Stabilized with Eudragit

This study describes the synthesis of Protorhus longifolia methanolic leaf extract-loaded Eudragit nanoparticles (NPs) and assessment of their antioxidant activity comparative to the free methanolic extract. The latter was also analyzed for its total phenolic content (TPC) and total flavonoid content (TFC). The extract-loaded NPs were obtained through the emulsification solvent evaporation process and systematically characterized using the dynamic light scattering, entrapment efficiency, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. The antioxidant power was determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing ability of plasma (FRAP) in vitro model systems. Screening of the different classes of secondary metabolites was carried out through chemical reaction tests. Identification of the potential antioxidants was performed using the gas chromatography-mass spectrometry (GC-MS) technique and the database of National Institute Standard and Technology (NIST). The characterization techniques showed spherical-like particles having an average size of 150[Formula: see text]nm and zeta potential of [Formula: see text]22[Formula: see text]mV. The percentage of entrapped methanolic extract was determined to be 83%. The antioxidant assay demonstrated that this methodology persuaded an efficient concentration-dependent potential. This study indicates that nanoformulation of the Protorhus longifolia extracts leads to a suitable system for the enhancement of antioxidant activity. The appraisal of other pharmacological activities of the nano-encapsulated Protorhus longifolia methanol extract is under process.

In situ Formed Implants, Based on PLGA and Eudragit Blends, for Novel Florfenicol Controlled Release Formulations

Drug controlled release technologies (DCRTs) represent an opportunity for designing new therapies. Main objectives are dose number optimization and secondary effects reduction to improve the level of patient/client acceptance. The present work studies DCRTs based in blended polymeric implants for single dose and long-term therapies of florfenicol (FF), a broad spectrum antibiotic. Polymers used were PLGA and Eudragit E100/S100 types. Eudragit/PLGA and FF/PLGA ratios were the main studied factors in terms of encapsulation efficiencies (EEs) and drug release profiles. In addition, morphological and physicochemical characterization were carried out. EEs were of 50-100% depending on formulation composition, and the FF releasing rate was increased or diminished when E100 or S100 were added, respectively. PLGA hydrolytic cleavage products possibly affect Eudragit solubility and matrix stability. Different mathematical models were used for better understanding and simulating release processes. Implants maintained the antimicrobial activity against Pseudomonas aeruginosa up to 12 days on agar plates. The developed DCRTs represents a suitable alternative for florfenicol long-term therapies.

Sustained release dosage form of noscapine HCl using hot melt extrusion (HME) technique: formulation and pharmacokinetics

Sustained release formulation of noscapine (Nos) HCl could be useful in maintaining plasma Nos HCl level for prolonged period of time, which is important for chemo-sensitization. However, weakly basic drugs like Nos HCl have pH-dependent solubility. Therefore, the purpose of this study was to achieve pH-independent drug release by developing the sustained release dosage form of Nos HCl using biodegradable polymer Eudragit RLPO and FDA-approved pH modifier citric acid (CA) by hot melt extrusion (HME) technique. Nos HCl was successfully formulated using 10% CA with 91.2 ± 1.34% drug recovery through the extruder. X-ray diffraction (XRD) results showed that drug was completely dispersed in the polymer and changed to amorphous from its crystalline form. In vitro drug release studies in pH 6.8 buffer showed that formulation containing 10% CA released 70.99 ± 3.85% drug in 24 h after initial burst release of 40.04 ± 2.39% compared to formulation without CA. Furthermore, in vivo pharmacokinetic data showed the sustained release plasma concentration time curve with significant (p < 0.05) increase in area under curve (AUC) in Nos HCl extrudate compared to Nos HCl solution. Overall, HME can be used to enhance the bioavailability and achieve the pH-independent solubility of weakly basic drugs like Nos HCl. Graphical abstract.

Recent advances in mesalamine colonic delivery systems

Background

Increased attention has been focused on the continuous development and improvement of mesalamine colonic specific delivery systems, for the effective treatment of inflammatory bowel diseases; thus enhancing therapeutic efficacy and reducing potential side effects. Mesalamine is a class IV drug, according to the Biopharmaceutics Classification System, used usually to treat inflammation associated with colon related diseases such as Crohn’s disease and ulcerative colitis.

Main text

An ideal colon targeting system aims to deliver a therapeutic agent, selectively and effectively, to the colon. This system should ideally retain the drug release in the upper GI tract (stomach and small intestine); while trigger the drug release in the colon. Several approaches have been used to fabricate formulations to achieve a colon specific delivery of mesalamine such as; time dependent, pH responsive, enzymatic/microbial responsive and ultrasound mediated approaches. This overview outlines the recent advances in mesalamine-colon delivery approaches for the potential treatment of ulcerative colitis and Crohn’ disease.

Conclusion

A combined pH-time dependent delivery system can improve mesalamine colonic drug delivery via employing carriers capable of retarding mesalamine release in the stomach and delivering it at predetermined time points after entering the intestine. The existence of specific enzymes, produced by various anaerobic bacteria present in the colon advocates the advantage of designing enzyme sensitive systems and combining it with pH-time dependent system to improve mesalamine colonic delivery. The use of ultrasound has shown promises to effectively treat inflammatory bowel diseases.

Artificial Neural Network (ANN) Approach to Predict an Optimized pH-Dependent Mesalamine Matrix Tablet

Background

Severe bleeding and perforation of the colon and rectum are complications of ulcerative colitis which can be treated by a targeted drug delivery system.

Purpose

Development of colon-targeted delivery usually involves a complex formulation process and coating steps of pH-sensitive methacrylic acid based Eudragit^®. The current work was purposefully designed to develop dicalcium phosphate (DCP) facilitated with Eudragit-S100-based pH-dependent, uncoated mesalamine matrix tablets.

Materials and Methods

Mesalamine formulations were compressed using wet granulation technique with varying compositions of dicalcium phosphate (DCP) and Eudragit-S100. The developed formulations were characterized for physicochemical and drug release profiles. Infrared studies were carried out to ensure that there was no interaction between active ingredients and excipients. Artificial neural network (ANN) was used for the optimization of final DCP-Eudragit-S100 complex and the experimental data were employed to train a multi-layer perception (MLP) using quick propagation (QP) training algorithm until a satisfactory root mean square error (RMSE) was reached. The ANN-aided optimized formulation was compared with commercially available Masacol^®.

Results

Compressed tablets met the desirability criteria in terms of thickness, hardness, weight variation, friability, and content uniformity, ie, 5.34 mm, 7.7 kg/cm^2, 585±5 mg (%), 0.44%, and 103%, respectively. In-vitro dissolution study of commercially available mesalamine and optimized formulation was carried out and the former showed 100% release at 6 h while the latter released only 12.09% after 2 h and 72.96% after 12 h which was fitted to Weibull release model with b value of 1.3, indicating a complex release mechanism.

Conclusion

DCP-Eudragit-S100 blend was found explicative for mesalamine release without coating in gastric and colonic regions. This combination may provide a better control of ulcerative colitis.

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Eudragit®-S100 Coated PLGA Nanoparticles for Colon Targeting of Etoricoxib: Optimization and Pharmacokinetic Assessments in Healthy Human Volunteers

Aim

Etoricoxib is a selective inhibitor of COX-2 enzyme. It is proposed as a potent anti-inflammatory drug intended for the control of irritable bowel syndrome. The current work aimed at developing etoricoxib-loaded nanoparticles for colon- targeting.

Materials and Methods

PLGA nanoparticles were developed via nano-spray drying technique. The D-optimal design was adopted for the investigation of the influence of i) DL-lactide-coglycolide (PLGA) concentration, ii) polyvinylpyrrolidone K30 (PVP K30) concentration and iii) lactide:glycolide ratio in the copolymer chain on the yield%, the encapsulation efficiency (EE%), particle size (PS) and percentage of drug release after 2h (P_2h), 4h (P_4h) and 12h (P_12h). To promote colon targeting of the systems, the best achieved system (M14) was either directly coated with poly(methacrylic acid-co-methyl methacrylate) [Eudragit^®-S100] or loaded into hard gelatin capsules and the capsules were coated with poly(methacrylic acid-co-methyl methacrylate) (E-M14C). The pharmacokinetic parameters of etoricoxib following oral administration of E-M14C in healthy volunteers were assessed relative to commercial etoricoxib tablets.

Results

M14 system was prepared using PLGA (0.5% w/v) at a lactide:glycolide ratio of 100:0, in the presence of PVP K30 (2% w/v). M14 system was nano-spherical particles of 488 nm size possessing promising yield% (63.5%) and EE% (91.2%). The percentage drug released after 2, 4 and 12 hours were 43.41%, 47.34 and 64.96%, respectively. Following M14-loading into hard gelatin capsules and coating with poly(methacrylic acid-co-methyl methacrylate) [Eudragit-S100], the respective P_2h, P_4h and P_12h were 10.1%, 28.60% and 65.45%. Significant (p < 0.05) differences between the pharmacokinetic parameter of E-M14C in comparison with the commercial product were revealed with a delay in T_max (from 2.5h to 6h), a prolongation in MRT_0-∞ (from 24.4h to 34.7h) and an increase in the relative oral bioavailability (4.23 folds).

Conclusion

E-M14C is a potential system for possible colon targeting of etoricoxib.

Eudragit S100 Entrapped Liposome for Curcumin Delivery: Anti-Oxidative Effect in Caco-2 Cells

Curcumin is a natural polyphenol with strong antioxidant activity. However, this molecule shows a very poor bioavailability, instability, and rapid metabolism in vivo. In this work curcumin was loaded in Eudragit-coated liposomes to create a gastroresistant carrier, able to protect its load from degradation and free it at the site of absorption in the colon region. Small unilamellar vesicles were prepared and coated with Eudragit by a pH-driven method. The physico-chemical properties of the prepared systems were assessed by light scattering, transmission electron microscopy, infrared spectroscopy, and differential scanning calorimetry. The uptake of vesicles by Caco-2 cells and the anti-oxidant activity in cells were evaluated. The produced vesicles showed dimensions of about forty nanometers that after covering with Eudragit resulted to have micrometric dimensions at acid pH. The experiments showed that at pH > 7.0 the polymeric coating dissolves, releasing the nanometric liposomes and allowing them to enter Caco-2 cells. Delivered curcumin loaded vesicles were then able to decrease significantly ROS levels as induced by H2O2 in Caco-2 cells. The proposed work showed the possibility of realizing effective gastroresistant curcumin liposome formulations for the delivery of antioxidant molecules to Caco-2 cells, potentially applicable to the treatment of pathological conditions related to intestinal oxidative stress.

Ternary nanocomposite carriers based on organic clay-lipid vesicles as an effective colon-targeted drug delivery system: preparation and in vitro/in vivo characterization

This study aimed to develop a new colon-targeted drug delivery system via the preparation of ternary nanocomposite carriers based on organic polymer, aminoclay and lipid vesicles. Budesonide (Bud), an anti-inflammatory drug was chosen as a model drug and encapsulated into three different formulations: liposome (Bud-Lip), aminoclay-coated liposome (AC-Bud-Lip), and Eudragit® S100-aminoclay double coated liposome (EAC-Bud-Lip). The formation of the aminoclay-lipid vesicle nanocomposite was confirmed by energy dispersive X-ray spectrum, transmission electron microscopy, and Fourier-transform infrared spectroscopy. All formulations were produced with a high encapsulation efficiency in a narrow size distribution. Drug release from EAC-Bud-Lip was approximately 10% for 2-h incubation at pH 1.2, implying the minimal drug release in acidic gastric condition. At pH 7.4, EAC-Bud-Lip underwent significant size reduction and exhibited drug release profiles similar to that from AC-Bud-Lip, implying the pH-dependent removal of the outer coating layer. Compared to free Bud solution, EAC-Bud-Lip achieved a higher drug uptake in Caco-2 cells and exhibited a stronger inhibition of TNF-α and IL-6 secretion in LPS-stimulated Raw264.7 cells. Furthermore, a bio-distribution study in mice demonstrated that Eudragit® S100-aminoclay dual coating led to a higher colonic distribution with a longer residence time, which correlated well with the delayed systemic drug exposure in rats. Taken together, the present study suggests that the ternary nanocomposite carrier consisting of Eudragit® S100, aminoclay, and lipid vesicle might be useful as an effective colon-targeted drug delivery system.

Vaginal Polyelectrolyte Layer-by-Layer Films Based on Chitosan Derivatives and Eudragit® S100 for pH Responsive Release of Tenofovir

Women are still at high risk of contracting the human immunodeficiency virus (HIV) virus due to the lack of protection methods under their control, especially in sub-Saharan countries. Polyelectrolyte multilayer smart vaginal films based on chitosan derivatives (chitosan lactate, chitosan tartate, and chitosan citrate) and Eudragit^® S100 were developed for the pH-sensitive release of Tenofovir. Films were characterized through texture analysis and scanning electron microscopy (SEM). Swelling and drug release studies were carried out in simulated vaginal fluid and a mixture of simulated vaginal and seminal fluids. Ex vivo mucoadhesion was evaluated in bovine vaginal mucosa. SEM micrographs revealed the formation of multilayer films. According to texture analysis, chitosan citrate was the most flexible compared to chitosan tartrate and lactate. The swelling studies showed a moderate water uptake (<300% in all cases), leading to the sustained release of Tenofovir in simulated vaginal fluid (up to 120 h), which was accelerated in the simulated fluid mixture (4–6 h). The films had high mucoadhesion in bovine vaginal mucosa. The multilayer films formed by a mixture of chitosan citrate and Eudragit^® S100 proved to be the most promising, with zero toxicity, excellent mechanical properties, moderate swelling (<100%), high mucoadhesion capacity, and Tenofovir release of 120 h and 4 h in vaginal fluid and the simulated fluid mixture respectively.

Glycyrrhizic acid-loaded pH-sensitive poly-(lactic-co-glycolic acid) nanoparticles for the amelioration of inflammatory bowel disease

Aim: To fabricate and evaluate the therapeutic efficacy of glycyrrhizic acid (GA)-loaded pH-sensitive nanoformulations that specifically target and combat mucosal inflammation of the colon. Methods: GA-loaded Eudragit® S100/poly-(lactic-co-glycolic acid) nanoparticles were developed through modified double-emulsion evaporation coupled with solvent evaporation coating techniques and analyzed for physicochemical characteristics, surface chemistry, release kinetics, site-retention and therapeutic effectiveness. Results: Nanoparticles have a particle size of approximately 200 nm, high encapsulation efficiency, desired surface chemistry with pH-dependent and sustained drug release behavior following the Gompertz kinetic model. In vivo retention and therapeutic effectiveness in the inflamed colon tissues were confirmed by macroscopic and microscopic indices, cytokine analysis and antioxidant assays. Conclusion: GA-loaded Eudragit S100/poly-(lactic-co-glycolic acid) nanoparticles could efficiently deliver GA to the colon and ameliorate the mucosal inflammation for a prolonged duration.

Enhanced Biopharmaceutical Performance of Rivaroxaban through Polymeric Amorphous Solid Dispersion

Rivaroxaban (RXB) is an orally active direct inhibitor of the activated serine protease Factor Xa, given as monotherapy in the treatment of venous thromboembolism (VTE). It has been characterized in vitro as a substrate for the active, nonsaturable efflux via P-gp transporter, limiting its high permeability. Therefore, the role of P-gp inhibiting polymers in enhancing the biopharmaceutical performance of RXB by preparing polymeric amorphous solid dispersion and subsequent improvement in solubility and permeability was investigated. Initially, solubility parameter and Flory-Huggins interaction parameter were determined for miscibility studies between drug and polymers. Binary dispersions were prepared by dissolving drug with polymers eudragit S100, eudragit L100, and soluplus in common solvent (5% v/v water in tetrahydrofuran) using spray dryer. Prepared binary dispersions were analyzed by differential scanning calorimetry (DSC), microscopy, powder X-ray diffractometry (PXRD), Fourier transform infrared spectroscopy (FTIR), dynamic vapor sorption (DVS), and solution nuclear magnetic resonance (NMR) spectroscopy. Superior performance of binary dispersions was observed upon dissolution and solubility studies over micronized active pharmaceutical ingredient. Amorphous solid dispersion (ASD) prepared with soluplus showed 10-fold increase in apparent solubility and maintenance of supersaturation for 24 h compared to the crystalline RXB. Further, pharmacokinetic study performed in animals was in good correlation with the solubility data. Increases of 5.7- and 6.7-fold were observed in AUC and C_max, respectively, for ASDs prepared with soluplus compared to those with crystalline RXB. FTIR and NMR spectroscopy unveiled the involvement of N-H group of RXB with C═O group of polymers in intermolecular interactions. The decreased drug efflux ratio was observed for ASDs prepared with eudragit S100 and soluplus in Caco-2 transport study suggesting improvement in the absorption of RXB. Hence, the present study demonstrates ASD using soluplus as a promising formulation strategy for enhancing the biopharmaceutical performance of RXB by increasing the solubility and circumventing the P-gp activity.

Application of three-dimensional printing for colon targeted drug delivery systems

Orally administered solid dosage forms currently dominate over all other dosage forms and routes of administrations. However, human gastrointestinal tract (GIT) poses a number of obstacles to delivery of the drugs to the site of interest and absorption in the GIT. Pharmaceutical scientists worldwide have been interested in colon drug delivery for several decades, not only for the delivery of the drugs for the treatment of colonic diseases such as ulcerative colitis and colon cancer but also for delivery of therapeutic proteins and peptides for systemic absorption. Despite extensive research in the area of colon targeted drug delivery, we have not been able to come up with an effective way of delivering drugs to the colon. The current tablets designed for colon drug release depend on either pH-dependent or time-delayed release formulations. During ulcerative colitis the gastric transit time and colon pH-levels is constantly changing depending on whether the patient is having a relapse or under remission. Hence, the current drug delivery system to the colon is based on one-size-fits-all. Fails to effectively deliver the drugs locally to the colon for colonic diseases and delivery of therapeutic proteins and peptides for systemic absorption from the colon. Hence, to overcome the current issues associated with colon drug delivery, we need to provide the patients with personalized tablets which are specifically designed to match the individual's gastric transit time depending on the disease state. Three-dimensional (3D) printing (3DP) technology is getting cheaper by the day and bespoke manufacturing of 3D-printed tablets could provide the solutions in the form of personalized colon drug delivery system. This review provides a bird's eye view of applications and current advances in pharmaceutical 3DP with emphasis on the development of colon targeted drug delivery systems.

Application of three-dimensional printing for colon targeted drug delivery systems

Orally administered solid dosage forms currently dominate over all other dosage forms and routes of administrations. However, human gastrointestinal tract (GIT) poses a number of obstacles to delivery of the drugs to the site of interest and absorption in the GIT. Pharmaceutical scientists worldwide have been interested in colon drug delivery for several decades, not only for the delivery of the drugs for the treatment of colonic diseases such as ulcerative colitis and colon cancer but also for delivery of therapeutic proteins and peptides for systemic absorption. Despite extensive research in the area of colon targeted drug delivery, we have not been able to come up with an effective way of delivering drugs to the colon. The current tablets designed for colon drug release depend on either pH-dependent or time-delayed release formulations. During ulcerative colitis the gastric transit time and colon pH-levels is constantly changing depending on whether the patient is having a relapse or under remission. Hence, the current drug delivery system to the colon is based on one-size-fits-all. Fails to effectively deliver the drugs locally to the colon for colonic diseases and delivery of therapeutic proteins and peptides for systemic absorption from the colon. Hence, to overcome the current issues associated with colon drug delivery, we need to provide the patients with personalized tablets which are specifically designed to match the individual's gastric transit time depending on the disease state. Three-dimensional (3D) printing (3DP) technology is getting cheaper by the day and bespoke manufacturing of 3D-printed tablets could provide the solutions in the form of personalized colon drug delivery system. This review provides a bird's eye view of applications and current advances in pharmaceutical 3DP with emphasis on the development of colon targeted drug delivery systems.