Sustained-release solid dispersion of pelubiprofen using the blended mixture of aminoclay and pH independent polymers: preparation and in vitro/in vivo characterization

Development of Amorphous Solid Dispersion Sustained-Release Formulations with Polymer Composite Matrix-Regulated Stable Release Plateaus

PURPOSE

This study was designed to develop ibuprofen (IBU) sustained-release amorphous solid dispersion (ASD) using polymer composites matrix with drug release plateaus for stable release and to further reveal intrinsic links between polymer' matrix ratios and drug release behaviors.

METHODS

Hydrophilic polymers and hydrophobic polymers were combined to form different composite matrices in developing IBU ASD formulations by hot melt extrusion technique. The intrinsic links between the mixed polymer matrix ratio and drug dissolution behaviors was deeply clarified from the dissolution curves of hydrophilic polymers and swelling curves of composite matrices, and intermolecular forces among the components in ASDs.

RESULTS

IBU + ammonio methacrylate copolymer type B (RSPO) + poly(1-vinylpyrrolidone-co-vinyl acetate) (PVP VA64) physical mixtures presented unstable release behaviors with large error bars due to inhomogeneities at the micrometer level. However, IBU-RSPO-PVP VA64 ASDs showed a "dissolution plateau phenomenon", i.e., release behaviors of IBU in ASDs were unaffected by polymer ratios when PVP VA64 content was 35% ~ 50%, which could reduce risks of variations in release behaviors due to fluctuations in prescriptions/processes. The release of IBU in ASDs was simultaneously regulated by the PVP VA64-mediated "dissolution" and RSPO-PVP VA64 assembly-mediated "swelling". Radial distribution function suggested that similar intermolecular forces between RSPO and PVP VA64 were key mechanisms for the "dissolution plateau phenomenon" in ASDs at 35% ~ 50% of PVP VA64.

CONCLUSIONS

This study provided ideas for developing ASD sustained-release formulations with stable release plateau modulated by polymer combinations, taking full advantages of simple process/prescription, ease of scale-up and favorable release behavior of ASD formulations.

Effect of hot-melt extruded Morus alba leaves on intestinal microflora and epithelial cells

Although rutin and isoquercitrin have many effects, they are insoluble substances, making it difficult to obtain pure substances. This study was to investigate whether Morus alba leaves containing rutin and isoquercitrin could improve intestinal health by making a sustained-release formulation through a hot-melt extrusion (HME) process with improved stability and solubility and determine whether it could upregulate the balance of intestinal microorganisms and intestinal epithelial cells. A sustained-release formulation was prepared by the HME process using Morus alba leaves and a hydrophilic polymer matrix. Antibacterial activities of pathogenic microorganisms (Escherichia coli, Streptococcus aureus, Enterococcus faecalis) and proliferative effect of probiotics (Lactobacillus rhamnosus, Pediococcus pentosaceus) were tested against intestinal microorganisms. Regarding intestinal epithelial cells, a co-culture model of Caco-2 cells and RAW 264.7 cells was used. It was confirmed that the extrudate exhibited high antibacterial activities against pathogenic microorganisms and affected the proliferation of probiotics. Furthermore, after inducing inflammation through LPS, it recovered transepithelial electrical resistance-increased levels of tight junction proteins and decreased expression levels of pro-inflammatory cytokines. HME of Morus alba leaves containing rutin and isoquercitrin can upregulate intestinal microbial balance and intestinal epithelial cells.

Organometallic Phyllosilicate-Gold Nanocomplex: An Effective Oral Delivery System of Methotrexate for Enhanced in vivo Efficacy Against Colorectal Cancer

Purpose

Oral administration, although convenient and preferred for treating colorectal cancer (CRC), faces challenges due to limited CRC-related intestinal positioning and a dense mucus barrier. In the present study, a gold-nanoparticle decorated-organometallic phyllosilicate nanocomposite (AC-Au), with a pH-dependent surface coating, was employed for more effective oral delivery of anticancer drugs to treat CRC.

Methods

The organometallic AC-Au was synthesized using the in-situ sol-gel method. Subsequently, methotrexate (MTX) was loaded into AC-Au, and the complex (AC-Au/MTX) was surface-coated with poly (methacrylic acid-co-methyl methacrylate) (1:2), a pH-dependent polymer (E/AC-Au /MTX). The in vitro characteristics of nanoparticles were examined using various analytical methods. In vivo efficacy studies were also conducted using an HCT-116 orthotopic colorectal cancer model.

Results

AC-Au emerged as a spherical nanoparticle with a mean size of 26.5 ± 0.43 nm, displaying a positive charge over the pH range of 2-10. Both the uncoated and coated drug-loaded nanocomplexes (AC-Au/MTX and E/AC-Au/MTX) were fabricated with high entrapment efficiency (> 80%). Various analyses, including ultraviolet-visible spectroscopy, X-ray powder diffraction, transmission electron microscopy, and energy dispersive X-ray spectroscopy, confirmed the formation of the nanocomplexes. While AC-Au/MTX achieved rapid and extensive drug release at the pH range of 1.2-7.4, E/AC-Au/MTX exhibited pH-dependent drug release, with approximately 23% at pH 1.2 and 74% at pH 7.4. Relative to free MTX, the AC-Au-based nanocomplex significantly enhanced the cytotoxicity of MTX in HCT-116 cells. Furthermore, orally administered E/AC-Au/MTX significantly improved the anti-tumor activity of MTX in an HCT-116 orthotopic colorectal cancer model, resulting in approximately 60% suppression of tumor mass compared with the positive control.

Conclusion

The organometallic AC-Au nanocomplex coated with a pH-dependent polymer has the potential to be an effective colonic drug delivery system of MTX, enhancing in vivo efficacy against colorectal cancer.

Sustained-Release Solid Dispersion of High-Melting-Point and Insoluble Resveratrol Prepared through Hot Melt Extrusion to Improve Its Solubility and Bioavailability

This study aimed to prepare a sustained-release solid dispersion of poorly water-soluble resveratrol (RES) with high melting point in a single hot melt extrusion step. A hydrophobic-hydrophilic polymeric blend (Eudragit RS and PEG6000) was used to control the release of RES. With the dispersive mixing and high shear forces of hot melt extrusion, the thermodynamic properties and dispersion of RES were changed to improve its solubility. The effects of the formulation were investigated through univariate analysis to optimize the preparation of the sustained-release solid dispersion. In vitro and in vivo studies were performed to evaluate the prepared RES/RS/PEG6000 sustained-release solid dispersion. The physical state of the solid dispersion was characterized using differential scanning calorimetry and X-ray diffraction. Surface properties of the dispersion were visualized using scanning electron microscopy, and the chemical interaction between RES and excipients was detected through Fourier-transform infrared spectroscopy. Results suggested that the optimized sustained-release solid dispersion was obtained when the mass ratio of RES-polymeric blend was 1:5, the ratio of PEG6000 was 35%, the barrel temperature was 170 °C, and the screw speed was 80 rpm. In vitro studies demonstrated that the solid dispersion showed a good sustained release effect. The cumulative release of RES reached 82.42% until 12 h and was fit by the Weibull model. In addition, the saturated solubility was 2.28 times higher than that of the bulk RES. In vitro studies demonstrated that the half-life increased from 3.78 to 7.09 h, and the bioavailability improved to 140.38%. The crystalline RES was transformed into the amorphous one, and RES was highly dispersed in the polymeric blend matrix.

Therapeutic Potential of Antileukotriene Drug-Camellia sinensis Extract Co-Formulation on Histamine Induced Asthma in Guinea Pigs

BACKGROUND/OBJECTIVE

To study the therapeutic potential of Antileukotriene drug- Camellia sinensis extract co-formulation on histamine induced asthma in guinea pigs.

METHODS

SRSD of Montelukast sodium was prepared by the solvent evaporation method. Lyophilized aqueous extract of Camellia sinensis leaves and SRSD mixture was filled in capsule and the capsule shell was coated to achieve initial release lag time. In vitro and pharmacokinetic study of capsules was performed and compared with commercial tablets. A further role of green tea, as an antioxidant adjunct for asthma management, has been analyzed by lung histology, mast cell count and oxidative stress assay in the serum of control and experimental animals.

RESULTS

The drug release from the commercial tablet was immediate and rapid, but capsule has shown an initial 3.5 hr lag time followed by sustained action up to 8 hr. Pharmacokinetic results show that studied formulations are bioequivalent with respect to Cmax and AUC, while rest parameters showed asignificant difference. Mast cells count in lung tissue were increased (p<0.001) in the experimental group along with glycoprotein deposition in asthmatic bronchioles. Levels of SOD and GPX were decreased (p<0.05) while CAT was increased (p<0.04) in the asthma group in comparison to control.

CONCLUSION

In the experimental animal model, co-formulation was effective in modulating allergic inflammation and contributing to better control of the inflammatory response. Our findings suggest that Camellia sinensis leaves extract may be used as an adjunct for future improvements in asthma treatment and prevention.

Overdose and Alcohol Sensitive Immediate Release System (OASIS) for Deterring Accidental Overdose or Abuse of Drugs

Death from an accidental or intentional overdose of sleeping tablets has increased exponentially in the USA. Furthermore, the simultaneous consumption of sleeping tablets with alcoholic beverages not only intensifies the effect of sleeping tablets but also leads to blackouts, sleepwalking, and death in many cases. In this article, we proposed a unique and innovative technology to prevent multi-tablet and alcohol-associated abuse of sleeping tablet. Agonist- and antagonist-loaded polymeric filaments of appropriate Eudragit® polymers were prepared using hot melt extrusion. Metoprolol tartrate and hydrochlorothiazide were used as model drugs in place of zolpidem tartrate (agonist-BCS class I) and flumazenil (antagonist-BCS class IV), respectively. Crushed filaments were converted into a tablet with a novel rapidly soluble co-processed alkalizing agent. Dissolution studies of single tablet and multiple tablets (5) in fasted state simulated gastric fluid (FaSSGF) confirmed that the release of the agonist was significantly (p < 0.0001) reduced in multi-tablet dissolution. Furthermore, the release of antagonist was significantly higher when tablet was exposed to FaSSGF+20% ethanol and various alcoholic beverages. Thus, appropriate use of Eudragit® polymer's chemistry could help design a tablet to prevent the release of agonist in case of overdose and simultaneous release of antagonist when consumed with alcohol.

Impact of drying on dissolution behavior of carvedilol-loaded sustained release solid dispersion: development and characterization

PURPOSE

The present study aimed to develop carvedilol (CAR)-loaded (25% w/w) sustained release solid dispersion (SRSD), for enhanced dissolution and to explore the applicability of different industrially accessible drying techniques.

METHODS

SRSD-CAR containing different ratios of polymers were prepared and physicochemically characterized. Dissolution study was carried out in both sink and supersaturated conditions to identify the possible enhancement in dissolution behavior.

RESULTS

Based on the solubility study, Kolliphor® P188 and Eudragit® RSPO (50:25, % w/w) ratio exhibited the highest solubility among the samples and was chosen as the optimal composition of SRSD-CAR for further characterization. The crystallinity assessments of the optimized formulation indicated amorphization of CAR in the formulation, bring about improved solubility of CAR. The infrared spectroscopic study revealed minor transitions; demonstrating the absence of significant interactions between drug and carrier. Furthermore, the SRSD-CAR exhibited immediate formation of nano particles when dispersed in water. Dissolution study revealed significant improvement in dissolution behavior, with a release of CAR in a gradual manner compared to crystalline CAR. From the dissolution kinetics analysis, the Korsmeyer Peppas model fit the best and diffusion was predominant in release of CAR. The drug release pattern showed insignificant differences between the SRSD-CAR formulations prepared by rotary vacuum drying and freeze drying.

CONCLUSION

From these experimental findings, SRSD approach might be a favorable dosage option for CAR, offering improved biopharmaceutical properties.

Hybrid Systems Based on Talc and Chitosan for Controlled Drug Release

Inorganic matrices and biopolymers have been widely used in pharmaceutical fields. They show properties such as biocompatibility, incorporation capacity, and controlled drug release, which can become more attractive if they are combined to form hybrid materials. This work proposes the synthesis of new drug delivery systems (DDS) based on magnesium phyllosilicate (Talc) obtained by the sol–gel route method, the biopolymer chitosan (Ch), and the inorganic-organic hybrid formed between this matrix (Talc + Ch), obtained using glutaraldehyde as a crosslink agent, and to study their incorporation/release capacity of amiloride as a model drug. The systems were characterized by X-ray diffraction (XRD), Therma analysis TG/DTG, and Fourier-transform infrared spectroscopy (FTIR) that supported the DDS’s formation. The hybrid showed a better drug incorporation capacity compared to the precursors, with a loading of 55.74, 49.53, and 4.71 mg g⁻¹ for Talc + Ch, Talc, and Ch, respectively. The release assays were performed on a Hanson Research SR-8 Plus dissolver using apparatus I (basket), set to guarantee the sink conditions. The in vitro release tests showed a prolongation of the release rates of this drug for at least 4 h. This result proposes that the systems implies the slow and gradual release of the active substance, favoring the maintenance of the plasma concentration within a therapeutic window.

Self-nanomicellizing solid dispersion of edaravone: part I - oral bioavailability improvement

Background

Edaravone (EDR) is known for its free radical scavenging, antiapoptotic, antinecrotic, and anticytokine effects in neurological and non-neurological diseases. It is currently available clinically as Radicava^® and Radicut^®, intravenous medications, recently approved for the treatment of amyotrophic lateral sclerosis and cerebral infarction. However, the oral use of EDR is still restricted by its poor oral bioavailability (BA) due to poor aqueous solubility, stability, rapid metabolism, and low permeability. The present study reports the development of novel EDR formulation (NEF) using self-nanomicellizing solid dispersion (SNMSD) strategy with the aim to enable its oral use.

Materials and methods

The selection of a suitable carrier for the development of NEF was performed based on the miscibility study. The optimization of EDR-to-carrier ratio was conducted via kinetic solubility study after preparing SNMSDs using solvent evaporation technique. The drug–polymer carrier interaction and self-nanomicellizing properties of NEF were investigated with advanced characterization studies. In vitro permeation, metabolism, and dissolution study was carried out to examine the effect of the presence of a carrier on physico-chemical properties of EDR. Additionally, the dose-dependent pharmacokinetic study of NEF was conducted and compared with the EDR suspension.

Results

Soluplus^® (SOL) as a carrier was selected based on the potential for improving aqueous solubility. The NEF containing EDR and SOL (1:5) resulted in the highest enhancement in aqueous solubility (17.53-fold) due to amorphization, hydrogen bonding interaction, and micellization. Moreover, the NEF demonstrated significant improvement in metabolism, permeability, and dissolution profile of EDR. Furthermore, the oral BA of NEF showed 10.2-, 16.1-, and 14.8-fold enhancement compared to EDR suspension at 46, 138, and 414 µmol/kg doses.

Conclusion

The results demonstrated that SNMSD strategy could serve as a promising way to enhance EDR oral BA and NEF could be a potential candidate for the treatment of diseases in which oxidative stress plays a key role in their pathogenesis.