Research Progress of Preparation Technology of Ion-Exchange Resin Complexes

Development and in vitro/in vivo evaluation of taste-masked orodispersible films of dapoxetine hydrochloride using ion exchange resins

Dapoxetine hydrochloride tablets are the most commonly used drug for the treatment of premature ejaculation (PE). However, the tablets must be taken with water 1-3 h before sexual activity, which makes the medication intake conspicuous and inconvenient. This study aimed to develop taste-masked orodispersible films (ODFs) of dapoxetine hydrochloride using ion exchange resins. It was found that the based-Kyron T-134 resin complex achieved a high drug loading of 75.9 ± 1.4%, establishing the mass ratio of dapoxetine hydrochloride to Kyron T-134 at 2:1, and adjusting the solution pH to 5.4 ± 0.05. The effect of pH on the drug loading of the resin was initially characterized by SEM, while the binding mechanism between dapoxetine hydrochloride and the resin was investigated by XRD, DSC, and FTIR. The ODFs exhibited favorable mechanical properties and palatability. Meanwhile, the drug release in both the ODFs and commercially available tablets Priligy® could reach 100.8% of the drug over 15 min in a simulated gastric fluid with pH 1.2 HCl. Furthermore, pharmacokinetic studies conducted in healthy volunteers demonstrated that the ODFs were bioequivalent to Priligy®. Therefore, this ODFs, characterized by its pleasant taste and water-free administration, offer a novel and convenient oral formulation for patients with PE, thereby enhancing patient compliance.

Current Trends in Development and Use of Polymeric Ion-Exchange Resins in Wastewater Treatment

Drinking and wastewater are to be treated for safe human consumption and for keeping surface waters clean. There are multiple water purification procedures, but the use of ion-exchange resins significantly enhances water purification efficiency. This review was targeted on highlighting the concept and classification of polymeric ion-exchange resins as well as pointing out their real-world applications. Their successful use for purification purposes has been linked to their chemical structure, simplicity of operation, accessibility, and reusability. Therefore, polymeric ion-exchange resins have been used for the removal of a wide range of organic and inorganic pollutants such as pharmaceutical compounds, dyes, organic matter, metals, and many others. Ion-exchange resins are obtained directly by synthesis methods or grafting ionizable groups on polymer matrix in order to ensure continuous improvement. Furthermore, the newly designed ion-exchange resins take into consideration biodegradability potential towards obtaining ecofriendly compounds.

Novel Sustained Release Azithromycin Resinate Fabricated by One-Pot Ion-exchange Performed in Hydro-alcoholic Solution

Drug-resin complexes usually form in the aqueous phase. For poorly water-soluble drugs, low drug loading limits the use of resin in drug formulation. In this study, we used a new method to prepare azithromycin resinates, improving the drug loading rate, shortening the preparation time and simplifying the process. We used hydro-alcoholic solution as the drug loading solvent and the ion exchange resin as the carrier, and this method enabled the resin to adsorb both the retardant and the drug. The sustained release effect of retardant Eudragit RL, RS100 was analyzed. Drug loading efficiency, release profiles, morphology, physicochemical characterization and pharmacokinetic study were assessed. Preparation of drug resinate by batch method resulted in 14% higher drug loading of azithromycin and 3.5 h shorter loading time as compared to pure water for hydroalcoholic solution as drug loading solvent. Raman mappings demonstrated that the retardant with higher molecular weight was more likely to adsorb to the outer layer of the resin compared to the drug. The in vitro release and in vivo pharmacokinetic study of azithromycin resinates showed a sustained release profile with few gastrointestinal adverse effects. Therefore, the addition of ethanol not only improved the efficiency of drug loading but also showed sustained-release effect with one-pot preparation of azithromycin resinates.

Natural resourced polysaccharides: Preparation, purification, structural elucidation, structure-activity relationships and regulating intestinal flora, a system review

Natural resourced polysaccharides (NRPs), as metabolites synthesized during activity of organisms, widely present in animal cell membranes or plant and microbial cell walls. NRPs have garnered extensive attention in the fields of medicine, foods, and farming owing to their distinct bioactivities and structural diversity. Despite the burgeoning growth in NRPs research, the available literature focuses primarily on a review of specific polysaccharides, necessitating an urgent need for a comprehensive summary of NRPs to offer readers a whole landscape of current advancements in NRPs research. Based on this, this article comprehensively reviews the latest research progress regarding preparation, purification, structure elucidation, structure-activity relationships and regulation of intestinal flora of NRPs in electronic databases, such as PubMed, Wiley, ScienceDirect and Web of Science from last 5 years. This review analyzes the effects of various extraction techniques on NRPs and also delves into the intrinsic correlation between the biological activity and structure of NRPs, highlighting that chemical modification can enhance their structural diversity and confer novel or improved biological functions. Moreover, this article extensively explores the application of NRP in promoting intestinal microecology balance, underscoring its significant potential as a probiotic initiator. This review lays a solid theoretical foundation for the future research and development of NRPs.

Drug-eluting contact lenses: Progress, challenges, and prospects

Topical ophthalmic solutions (eye drops) are becoming increasingly popular in treating and preventing ocular diseases for their safety, noninvasiveness, and ease of handling. However, the static and dynamic barriers of eyes cause the extremely low bioavailability (<5%) of eye drops, making ocular therapy challenging. Thus, drug-eluting corneal contact lenses (DECLs) have been intensively investigated as a drug delivery device for their attractive properties, such as sustained drug release and improved bioavailability. In order to promote the clinical application of DECLs, multiple aspects, i.e., drug release and penetration, safety, and biocompatibility, of these drug delivery systems were thoroughly examined. In this review, we systematically discussed advances in DECLs, including types of preparation materials, drug-loading strategies, drug release mechanisms, strategies for penetrating ocular barriers, in vitro and in vivo drug delivery and penetration detection, safety, and biocompatibility validation methods, as well as challenges and future perspectives.

Hot-Melt Extrusion: from Theory to Application in Pharmaceutical Formulation-Where Are We Now?

Hot-melt extrusion (HME) is a globally recognized, robust, effective technology that enhances the bioavailability of poorly soluble active pharmaceutical ingredients and offers an efficient continuous manufacturing process. The twin-screw extruder (TSE) offers an extremely resourceful customizable mixer that is used for continuous compounding and granulation by using different combinations of conveying elements, kneading elements (forward and reverse configuration), and distributive mixing elements. TSE is thus efficiently utilized for dry, wet, or melt granulation not only to manufacture dosage forms such as tablets, capsules, or granule-filled sachets, but also for designing novel formulations such as dry powder inhalers, drying units for granules, nanoextrusion, 3D printing, complexation, and amorphous solid dispersions. Over the past decades, combined academic and pharmaceutical industry collaborations have driven novel innovations for HME technology, which has resulted in a substantial increase in published articles and patents. This article summarizes the challenges and models for executing HME scale-up. Additionally, it covers the benefits of continuous manufacturing, process analytical technology (PAT) considerations, and regulatory requirements. In summary, this well-designed review builds upon our earlier publication, probing deeper into the potential of twin-screw extruders (TSE) for various new applications.

Drug complexes: Perspective from Academic Research and Pharmaceutical Market

Despite numerous research efforts, drug delivery through the oral route remains a major challenge to formulation scientists. The oral delivery of drugs poses a significant challenge because more than 40% of new chemical entities are practically insoluble in water. Low aqueous solubility is the main problem encountered during the formulation development of new actives and for generic development. A complexation approach has been widely investigated to address this issue, which subsequently improves the bioavailability of these drugs. This review discusses the various types of complexes such as metal complex (drug-metal ion), organic molecules (drug-caffeine or drug-hydrophilic polymer), inclusion complex (drug-cyclodextrin), and pharmacosomes (drug-phospholipids) that improves the aqueous solubility, dissolution, and permeability of the drug along with the numerous case studies reported in the literature. Besides improving solubility, drug-complexation provides versatile functions like improving stability, reducing the toxicity of drugs, increasing or decreasing the dissolution rate, and enhancing bioavailability and biodistribution. Apart, various methods to predict the stoichiometric ratio of reactants and the stability of the developed complex are discussed.

Paliperidone–Cation Exchange Resin Complexes of Different Particle Sizes for Controlled Release

This study aimed to develop electrolyte complexes of paliperidone (PPD) with various particle sizes using cation-exchange resins (CERs) to enable controlled release (both immediate and sustained release). CERs of specific particle size ranges were obtained by sieving commercial products. PPD–CER complexes (PCCs) were prepared in an acidic solution of pH 1.2 and demonstrated a high binding efficiency (>99.0%). PCCs were prepared with CERs of various particle sizes (on average, 100, 150, and 400 μm) at the weight ratio of PPD to CER (1:2 and 1:4). Physicochemical characterization studies such as Fourier-transform infrared spectroscopy, differential scanning calorimetry, powder X-ray diffraction, and scanning electron microscopy between PCCs (1:4) and physical mixtures confirmed PCC formation. In the drug release test, PPD alone experienced a complete drug release from PCC of >85% within 60 min and 120 min in pH 1.2 and pH 6.8 buffer solutions, respectively. Alternatively, PCC (1:4) prepared with CER (150 μm) formed spherical particles and showed an almost negligible release of PPD in pH 1.2 buffer (<10%, 2 h) while controlling the release in pH 6.8 buffer (>75%, 24 h). The release rate of PPD from PCCs was reduced with the increase in CER particle size and CER ratio. The PCCs explored in this study could be a promising technology for controlling the release of PPD in a variety of methods.

Methods and Characteristics of Drug Extraction from Ion-Exchange-Resin-Mediated Preparations: Influences, Thermodynamics, and Kinetics

Since the discovery of ion-exchange resins, they have been used in many fields, including pharmacy. Ion-exchange resin-mediated preparations can realize a series of functions, such as taste masking and regulating release. However, it is very difficult to extract the drug completely from the drug-resin complex because of the specific combination of the drug and resin. In this study, methylphenidate hydrochloride extended-release chewable tablets compounded by methylphenidate hydrochloride and ion-exchange resin were selected for a drug extraction study. The efficiency of drug extraction by dissociating with the addition of counterions was found to be higher than other physical extraction methods. Then, the factors affecting the dissociation process were studied to completely extract the drug from the methylphenidate hydrochloride extended-release chewable tablets. Furthermore, the thermodynamic and kinetic study of the dissociation process showed that the dissociation process obeys the second-order kinetic process, and it is nonspontaneous, entropy-decreasing, and endothermic. Meanwhile, the reaction rate was confirmed by the Boyd model, and the film diffusion and matrix diffusion were both shown to be rate-limiting steps. In conclusion, this study aims to provide technological and theoretical support for establishing a quality assessment and control system of ion-exchange resin-mediated preparations, promoting the applications of ion-exchange resins in the field of drug preparation.