Design and evaluation of an innovative floating and bioadhesive multiparticulate drug delivery system based on hollow structure

An Insight Into Risk Assessment and Reformulation of Drug Products Manufactured Using Benzene Grade Carbomer: A Regulatory Perspective

Cancer has been an enormous pain point for patients and regulatory bodies across the globe. In Dec. 2023, the US FDA released guidance on benzene-grade carbomer formulations, which triggered pharmaceutical manufacturers to assess risk, test finished products, and reformulate drug products with benzene-grade carbomer. The immediate implementation of the stoppage of finished products with benzene-grade carbomers has threatened pharmaceutical excipients and finished product manufacturers. The gravity of this situation prompted the US Pharmacopeia to extend the deadline for discontinuation from August 1, 2025, to August 1, 2026, allowing manufacturers ample time for reformulation and regulatory compliance.There is an immediate need to understand the guidance and to learn how manufacturers should do the risk assessment and approach reformulation. This review provides an in-depth analysis of the risk assessment and reformulation processes involved in various dosage forms utilizing benzene-grade carbomer, supported by specific case studies.This review offers insights into navigating the USFDA guidelines to ensure formulation safety and compliance, thus enabling pharmaceutical practitioners to uphold the highest standards of patient care and tackle life cycle management challenges.The decision of the USFDA to restrict the usage of high benzene content of carbomer in the formulation is a welcome move. This article has shown a way for researchers to see opportunities in the path and provide best-in-class medicines to patients with a better formulation safety profile.

Microparticles and multi-unit systems for advanced drug delivery

Microparticles have unique benefits in the formulation of multiparticulate and multi-unit type pharmaceutical dosage forms allowing improved drug safety and efficacy with favorable pharmacokinetics and patient centricity. On the other hand, the above advantages are served by high and well reproducible quality attributes of the medicinal product where even flexible design and controlled processability offer success as well as possible longer product life-cycle for the manufacturers. Moreover, the specific demands of patients can be taken into account, including simplified dosing regimens, flexible dosage, drug combinations, palatability, and ease of swallowing. In the more than 70 years since the first modified-release formulation appeared on the market, many new formulations have been marketed and many publications have appeared in the literature. More unique and newer pharmaceutical technologies and excipients have become available for producing tailor-made particles with micrometer dimensions and beyond. All these have contributed to the fact that the sub-units (e.g. minitablets, pellets, microspheres) that make up a multiparticulate system can vary widely in composition and properties. Some units have mucoadhesive properties and others can float to contribute to a suitable release profile that can be designed for the multiparticulate formula as a whole. Nowadays, there are some available formulations on the market, which are able to release the active substance even for several months (3 or 6 months depending on the type of treatment). In this review, the latest developments in technologies that have been used for a long time are presented, as well as innovative solutions such as the applicability of 3D printing to produce subunits of multiparticulate systems. Furthermore, the diversity of multiparticulate systems, different routes of administration are also presented, touching the ones which are capable of carrying the active substance as well as the relevant, commercially available multiparticle-based medical devices. The versatility in size from 1 µm and multiplicity of formulation technologies promise a solid foundation for the future applications of dosage form design and development.

Review on Starter Pellets: Inert and Functional Cores

A significant proportion of pharmaceuticals are now considered multiparticulate systems. Modified-release drug delivery formulations can be designed with engineering precision, and patient-centric dosing can be accomplished relatively easily using multi-unit systems. In many cases, Multiple-Unit Pellet Systems (MUPS) are formulated on the basis of a neutral excipient core which may carry the layered drug surrounded also by functional coating. In the present summary, commonly used starter pellets are presented. The manuscript describes the main properties of the various nuclei related to their micro- and macrostructure. In the case of layered pellets formed based on different inert pellet cores, the drug release mechanism can be expected in detail. Finally, the authors would like to prove the industrial significance of inert cores by presenting some of the commercially available formulations.

Applications of Bioadhesives: A Mini Review

Bioadhesives have demonstrated their superiority in clinical applications as tissue adhesives, hemostats, and tissue sealants. Because of the intrinsic stickiness, the applications have been expanded to various areas, such as functional wound dressing, factor delivery vehicles, and even medical device fixation. While many literature works discussed the mechanism of bioadhesives, few of them specifically summarized the applications of bioadhesives. To fill in the blanks, this review covers recent research articles and focuses precisely on the applications of bioadhesives which can be generally classified as follows: 1) wound closure, 2) sealing leakage, and 3) immobilization, including those already in the clinic and those showing great potential in the clinic. It is expected that this article will provide a whole picture on bioadhesives' applications and lead to innovations in the application of bioadhesives in new fields.

Raft-forming system for pantoprazole and domperidone delivery: in vitro and in vivo study

The raft is an emerging drug delivery system that not only provides rapid relief from reflux disorders, but also sustains drug release. The objective of this work was to develop and characterize raft-forming bilayer tablets in which pantoprazole sodium sesquihydrate (PSS) was targeted at sustained release and domperidone maleate (DM) was used to obtain an immediate-release effect and perform pharmacokinetic studies. Tablets were prepared using the wet granulation method. Rafts were characterized in terms of strength, weight, volume, resilience, acid-neutralizing capacity, floating lag time and total floating time. Dissolution studies were performed using simulated gastric fluid with pH 1·2. Compatibility were performed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction and differential scanning calorimetry (DSC). Percentage release of the optimized R7 formulation was 94% for PSS and 98% for DM. First-order release kinetics were followed and a non-Fickian diffusion was observed; the value of n was greater than 0·7 in the Korsmeyer–Peppas model. FTIR and DSC studies showed chemical and thermal stability between the drug and polymers. C max values of the test and reference formulations of PSS were 46·080 ± 0·567, 46·350 ± 0·507 and DM were 14·090 ± 1·678 and 10·560 ± 1·098 μg/ml, respectively.

Exploring the Potential of Hydrophilic Matrix Combined with Insoluble Film Coating: Preparation and Evaluation of Ambroxol Hydrochloride Extended Release Tablets

To explore the potential utility of combination of hydrophilic matrix with membrane-controlled technology, the present study prepared tablets of a water-soluble model drug (ambroxol hydrochloride), through process of direct compression and spray coating. Single-factor experiments were accomplished to optimize the formulation. In vivo pharmacokinetics was then performed to evaluate the necessity and feasibility of further development of this simple process and low-cost approach. Various release rates could be easily obtained by adjusting the viscosity and amount of hypromellose, pore-former ratios in coating dispersions and coating weight gains. Dissolution profiles of coated tablets displayed initial delay, followed by near zero-order kinetics. The pharmacokinetic study of different formulations showed that lag time became longer as the permeability of coating membrane decreased, which was consistent with the in vitro drug release trend. Besides, in vitro/in vivo correlation study indicated that coated tablets exhibited a good correlation between in vitro release and in vivo absorption. The results, therefore, demonstrated that barrier-membrane-coated matrix formulations were extremely promising for further application in industrialization and commercialization.

Premium ethylcellulose polymer based architectures at work in drug delivery

Premium ethylcellulose polymers are hydrophobic cellulose ether based biomaterials widely employed as biocompatible templates for the design of novel drug delivery systems. They are classified as United States Food and Drug Administration Generally-Recognized-As-Safe chemical substances and have been extensively utilized within the biomedical and pharmaceutical industries for over half a century. They have so far demonstrated the potential to modulate and improve the physiological performance of bioactives leading to the desired enhanced prophylactic and therapeutic outcomes. This review therefore presents a scholarly survey of inter-disciplinary developments focused on the functionalities of ethylcellulose polymers as biomaterials useful for the design of smart delivery architectures for relevant pharmacotherapeutic biomedical applications. Emphasis was placed on evaluating scientific resources related to recent advancements and future directions associated with its applications as delivery systems for drugs and biologics within the past decade thus complementing other specialized reviews showcasing the theme.

Modeling, design and manufacture of innovative floating gastroretentive drug delivery systems based on hot-melt extruded tubes

The problem of many gastroretentive systems is the mechanistic connection of drug release and gastric retention control. This connection could be successfully separated by formulating hollow tubes via hot-melt extrusion and sealing both tube ends, which led to immediately floating devices. The tube wall consisted of metformin crystals embedded in an inert polymer matrix of Eudragit® RS PO and E PO. Very high drug loadings of up to 80% (w/w) were used without generating a 'burst release'. Sustained release profiles from four to more than twelve hours were achieved by varying the polymer proportions without affecting the floatability. Buoyancy was found to mainly depend on the cylinder design, i.e. the outer to inner diameter ratio. This allowed the polymer/metformin composition to be changed without affecting buoyancy, i.e. a separation of floatability and release control was achieved. A prediction model was implemented that allowed for the buoyancy force to be determined with high accuracy by selecting a suitable ratio of outer to inner diameter of the modular tube die. Wall thickness and mass normalized surface area were identified as geometric parameters that mainly influenced the release properties. Conclusively, this study offers a highly flexible and rational manufacturing approach for the development of gastroretentive floating drug delivery systems.

Preparation and evaluation of gastro-floating hollow adhesive microspheres of carbomer/ethyl cellulose encapsulating dipyridamole

Gastro-floating hollow adhesive microspheres of Carbomer/ethyl cellulose encapsulating dipyridamole were fabricated and evaluated in vitro and in vivo.

Design and optimization of gastric floating sustained-release mini-tablets of alfuzosin hydrochloride based on a factorial design: in vitro/in vivo evaluation

The purpose of this research was to develop multiple-unit gastric floating mini-tablets and to evaluate the possibility of using these mini-tablets as a delivery system to improve the drug absorption for drugs with a narrow absorption window. Mini-tablets were prepared using hydroxypropyl methylcellulose (HPMC K100M) and carbopol 971P as release retarding agents and sodium bicarbonate (NaHCO₃) as gas-forming agent. The properties of the prepared mini-tablets in terms of floating characteristic parameters and in vitro release were evaluated. Furthermore, in vivo gastric retention study in rats and in vivo pharmacokinetic study in rabbits of the optimized formulation were performed. The optimized mini-tablets containing 45% HPMC K100M, 15% stearyl alcohol, 13% carbopol 971P, and 12% NaHCO₃ were found to float immediately within 1 min and duration more than 9 h. The in vivo gastric retention study results indicated that the mini-tablets could retain in the stomach for more than 6.67 h. Furthermore, the AUC_0-t of the floating mini-tablets (6849.83 ± 753.80 h ng·mL^-1) was significantly higher than that of marketed sustained-release tablets XATRAL®XL (4970.16 ± 924.60 h ng·mL^-1). All these results illustrated that the gastric floating mini-tablets might be a promising drug delivery system for drugs with a narrow absorption window.

Controlled-release nanoencapsulating microcapsules to combat inflammatory diseases

The World Health Organization (WHO) has reported that globally 235 million people suffer from chronic and other inflammatory diseases. The short half-lives of nonsteroidal anti-inflammatory drugs (NSAIDs) and their notoriety in causing gastrointestinal discomforts, warrants these drugs to be released in a controlled and sustained manner. Although polymeric particles have been widely used for drug delivery, there are few reports that showcase their ability in encapsulating and sustaining the release of NSAIDs. In this paper, polymeric nanoencapsulating microcapsules loaded with NSAIDs were fabricated using solid/water/oil/water emulsion solvent evaporation method. Two NSAIDs, ibuprofen and naproxen, were first pre-loaded into nanoparticles and then encapsulated into a larger hollow microcapsule that contained the third NSAID, celecoxib. A high encapsulation efficiency (%) of these NSAIDs was achieved and a sustained release (up to 30 days) of these drugs in phosphate-buffered saline was observed. Then, a gastrointestinal drug - cimetidine (CIM) - was co-loaded with the NSAIDs. This floating delivery system exhibited excellent buoyancy (~88% up to 24 h) in simulated gastric fluid. It also allowed a sequential release of the drugs, whereby an immediate release of CIM followed by NSAIDs was observed. Drug release of the NSAIDs observed Fickian diffusion mechanism, whereas CIM observed non-Fickian diffusion. Therefore, this delivery system is a promising platform to control the delivery of NSAIDs to combat inflammatory diseases, thereby protecting against possible gastrointestinal side effects that may arise from the overuse of NSAIDs.