Ion-exchange complex of famotidine: sustained release and taste masking approach of stable liquid dosage form

Oral Drug Delivery Systems Applied to Launched Products: Value for the Patients and Industrial Considerations

Drug delivery systems (DDS) control the amount, rate, and site of administration of drug substances in the body as well as their release and ADME (absorption, distribution, metabolism, excretion). Among the various types of DDS, amount-controlled DDS for solubilization and absorption increase the bioavailability. Time- and amount-controlled DDS are controlled release formulations classified as (1) membrane-type, (2) matrix-type, (3) osmotic-type, and (4) ion-exchange type. Timed-release formulations also control the time and amount of release and the absorption of drugs. Site- and amount-controlled DDS are characterized by colonic delivery and intestinal lymph-targeting to improve release and ADME of drug substances. Finally, site-, time-, and amount-controlled DDS are gastroretentive formulations and local delivery in the oral cavity to improve site retention, release, and ADME of drugs. DDS can enhance efficacy, reduce adverse effects, and optimize the dosing frequency of various drug products to increase patient value. This review focuses on patient value and industrial considerations of launched oral DDS. We provide a technological overview of candidate and marketed DDS, as well as the pros/cons of the technologies for industrialization with consideration to excipients, manufacturing, and storage stability. Moreover, to demonstrate the usefulness of the technology and support the selection and development of the best technologies for patients, we also describe patient value from clinical studies and analyses, particularly with regard to increased new medical options, higher efficacy, reduced adverse effects, reduced number of doses and clinic visits, easier administration, higher quality of life, greater adherence, and satisfaction.

Research Progress of Preparation Technology of Ion-Exchange Resin Complexes

As insoluble polymer materials, ion-exchange resins (IERs) can exchange their own ions with desirable charged ions in the solution. According to the affinity of active moieties for soluble counterions, IERs could be categorized into the following four types: strongly acidic cation, weakly acidic cation, strongly basic anion, and weakly basic anion exchange resins. Due to their relative safety and high drug-loading capacity, IERs have garnered extensive attention in the pharmaceutical field since the 1950s. As numerous investigations combine drugs with IERs, this article summarizes the technologies employed in these studies from four aspects: IER screening principles, combining technologies, characterization methods, and in vitro and in vivo release of drug-resinate complexes. In addition, the advantages and disadvantages of various technologies and their scope are expounded. The article provides new insights on the preparation of ion-exchange resin complexes.

Investigation of Chloroquine Resinate Feasibility and In Vitro Taste Masking Evaluation for Pediatric Formulations

In this study, chloroquine resinates were prepared at a 1:1 (w:w) drug-to-resin ratio using the batch method with polacrilex (PC), sodium polystyrene sulfonate (SPS), and polacrilin potassium (PP) ion exchange resins (IER). The influence of drug/resin ratio and pH of the medium on drug loading efficiency was explored. UV-VIS spectrophotometric analysis showed that SPS resin had high loading efficiency for chloroquine diphosphate (CLP), above 89%, regardless of the pH. PP resin was more effective at pH 5.0 (90.68%) than at pH 1.0 (2.09%), and PC resin had only 27.63% of CLP loading efficiency. CLP complexation with IER yielded amorphous mixtures according to results from differential scanning calorimetry (DSC) and X-ray powder diffraction (XRPD), thus indicating drug-resin interaction. The taste masking efficiency was evaluated with in vitro methods using an adapted dissolution test and an electronic tongue system. During dissolution tests, SPS released only 1.0% of CLP after 300 s, while PP released over 10% after 90 s in simulated saliva solution. The electronic tongue distinguished the samples containing CLP, resins, and resinates by using multidimensional projection techniques that indicated an effective drug taste masking. In an accelerated stability study, the drug contents did not decrease in chloroquine resinates, and there was no physical degradation of the resinates after 60 days. Using chloroquine resinates therefore represents a novel way to evaluate taste masking in vitro which is relevant for the early formulation development process.

Study on the Complexation and Release Mechanism of Methylphenidate Hydrochloride Ion Exchange Resin Complex

Since the advent of ion exchange resin, it has been widely used in many fields, including drug delivery systems. The drug binds to the resin through an exchange reaction to form a drug–resin complex, which can gradually release drugs through the exchange of physiological ions in the gastrointestinal tract, to realize functions such as taste masking and regulating release. In this study, the complexes of methylphenidate hydrochloride and Amberlite IRP69 were prepared and evaluated to explore the mechanism of complexation, influencing factors and release mechanism at a molecular level. Firstly, with the properties of the selected complexes, molecular dynamics simulation was innovatively used to find that the intermolecular interaction between drug molecules and ion exchange resin molecules is mainly caused by the stacking effect of π and salt bridges. Secondly, with the drug loading status as an indicator, the factors affecting the compounding process of the drug and resin were explored. Finally, the release mechanism of the drug–resin complex was studied by mathematical model fitting. In summary, a variety of methods were used to study the mechanism of complexation and release between drug and resin, providing a theoretical basis for promoting the marketing of ion−exchange resin−mediated oral preparations.

Design of 3-aminophenol-grafted polymer-modified zinc sulphide nanoparticles as drug delivery system

Zinc sulphide (ZnS) nanoparticles were synthesized by the coprecipitation method. The ZnS nanoparticle surface was polymerized with allyl glycidyl ether (AGE), and 3-aminophenol was then deposited as a ligand on nanosorbent. The modified nanosorbent was investigated with Fourier transform infrared spectroscopy and thermogravimetric analysis. The particle size of the modified nanosorbent was studied with scanning electron microscopy. Some characteristic factors of the adsorption process such as pH and time were investigated for famotidine using the modified nanosorbent. The equilibrium adsorption study of famotidine by 3-aminophenol-grafted AGE/ZnS was analysed by adsorption isotherms of the Langmuir, Freundlich, and Temkin models. The famotidine-releasing process was investigated in simulated biological fluids (intestinal fluid at pH of 7.4 and gastric fluid at pH of 1.2) and demonstrated 65% and 73% famotidine release during periods of 30 h (pH = 7.4) and 60 min (pH = 1.2), respectively. These results reveal the optimal performance of 3-aminophenol-grafted AGE/ZnS for sustained drug delivery.

Transforming Complexity to Simplicity: Protein-Like Nanotransformer for Improving Tumor Drug Delivery Programmatically

It was difficult for nanodrugs to simultaneously meet the contradictory requirements of prolonged circulation time, augmented cellular uptake, rapid lysosome escape, precise drug release, and tumor penetration in tumor drug delivery. We prepared a nanotransformer (DTIG) through assembling doxorubicin, tannic acid, and indocyanine green to overcome this dilemma. Hydrophilic DTIG showed prolonged blood circulation time. Besides, DTIG could be efficiently internalized by tumor cells through transforming into hydrophobic particles in an acidic tumor microenvironment. Subsequently, oversized hydrophobic particles were further formed in acidic lysosomes to escape from it through rupturing the lysosome. These hydrophobic DTIGs could rapidly revert to a smaller hydrophilic nanoassembly and release the payloads in cytoplasm. Similar to denaturation and renaturation of protein, these high-efficiency instantaneous transformations were activated by proton. Besides, photothermal therapy of DTIG promoted drug penetration efficiency in tumor. This optimized drug delivery process of DTIG finally offered potent antitumor efficacy and an obvious advantage on prognosis.

Fabrication of Hierarchical Polymeric Thin Films by Spin Coating Toward Production of Amorphous Solid Dispersion for Buccal Drug Delivery System: Preparation, Characterization, and In Vitro Release Investigations

The landscape of thin films is continuously evolving as an attractive self-administration mean to drive patient compliance. This work reports incorporation of drugs into various polymeric compositions using spin coating technology to screen amorphous solid dispersion film formation for buccal applications. Polarized light microscopy and differential scanning calorimetry were used for characterization. Physical stability was assessed after films storage at 0% RH/25°C for 6 months. Chlorpheniramine maleate, theophylline, and famotidine were used as model drugs and mixed with Opadry amb II^® or Kollicoat IR^®. Acryl-EZE II^® or Zein was also used as surface (design I) or surface and base polymers (design II). Of all the drug-Opadry combinations, only chlorpheniramine was amorphously dispersed up to 25% (w/w). In contrast, Kollicoat IR^® resulted in amorphous dispersions of all the tested drugs, suggesting that it has a better solubilization capacity. Drugs prepared in design II achieved higher in vitro release compared to respective design I, indicating that lower content of Acryl-EZE II^® or Zein can decrease drug release over 3 h. It has been also revealed that Zein could improve physical stability of the aged theophylline solid-dispersed films. Release kinetics of model drugs were satisfactory when described by first-order kinetics, facilitated through anomalous transport of both diffusion and polymer swelling.

Preparation and Evaluation of Taste Masking Iron Suspension: Taking Advantage of Weak Cationic Exchange Resin

The objective of this study is to use weak acid cation exchange resin to mask the taste and eliminate the teeth staining problems of ferrous sulfate liquid preparations for use in pediatrics. Amberlite IPR64 was loaded by Fe(II). Then, different suspensions of the iron-resin complex were prepared using various polymers as the suspending agents, and sorbitol as well as sucrose as sweeteners. Physical stability, rheological assessment, kinetics of Fe(II) release, and taste evaluation of suspensions were studied. The results implied that the prepared iron suspension was more stable when xanthan gum is used as the suspending agent. It was also shown that iron release in 0.7% NaCl (similar to saliva) was very negligible compared to relatively quick release in acidic medium (resembled the stomach). Overall, the volunteers confirmed that the formulations were successful in iron taste masking. The pH-dependent process of ion exchange by weak cationic resins opens an attractive approach to access a taste-masked iron suspension for infants.

Mechanical microencapsulation: The best technique in taste masking for the manufacturing scale - Effect of polymer encapsulation on drug targeting

Drug taste masking is a crucial process for the preparation of pediatric and geriatric formulations as well as fast dissolving tablets. Taste masking techniques aim to prevent drug release in saliva and at the same time to obtain the desired release profile in gastrointestinal tract. Several taste masking methods are reported, however this review has focused on a group of promising methods; complexation, encapsulation, and hot melting. The effects of each method on the physicochemical properties of the drug are described in details. Furthermore, a scoring system was established to evaluate each process using recent published data of selected factors. These include, input, process, and output factors that are related to each taste masking method. Input factors include the attributes of the materials used for taste masking. Process factors include equipment type and process parameters. Finally, output factors, include taste masking quality and yield. As a result, Mechanical microencapsulation obtained the highest score (5/8) along with complexation with cyclodextrin suggesting that these methods are the most preferable for drug taste masking.