Bioavailability enhancement of atovaquone using hot melt extrusion technology

Exploring the impact of material selection on the efficacy of hot-melt extrusion

Hot-melt extrusion (HME) has emerged as a versatile and efficient technique in pharmaceutical formulation development, particularly for enhancing the solubility and bioavailability of poorly water-soluble drugs. This review delves into the fundamental principles of HME, exploring its application in drug delivery systems. A comprehensive analysis of polymers utilized in HME, such as hydroxypropyl methylcellulose, ethyl cellulose, hydroxypropyl cellulose, and polyvinylpyrrolidone, is presented, highlighting their roles in achieving controlled drug release and improved stability. The incorporation of plasticizers, such as triacetin, poly(propylene glycol), glycerol, and sorbitol, is critical in reducing the glass transition temperature (Tg) of polymer blends, thereby enhancing the processability of HME formulations. A comparison of Tg values for various polymer-plasticizer combinations is discussed using different predictive models. For researchers and industry professionals looking to optimize drug formulation strategies, this article offers valuable insights into the mechanisms through which HME enhances drug solubility and bioavailability two critical factors in oral drug delivery. Furthermore, by reviewing recent patents and marketed formulations, the article serves as a comprehensive resource for understanding both the technical advancements and commercial applications of HME. Readers will gain a deep understanding of the role of polymers and additives in HME, alongside future perspectives on how emerging materials and techniques could further revolutionize pharmaceutical development. This review is essential for those aiming to stay at the forefront of pharmaceutical extrusion technologies and their potential to improve therapeutic outcomes. The review concludes that meticulous material selection is vital for advancing pharmaceutical manufacturing processes and ensuring optimal outcomes in HME applications, thereby enhancing the overall efficacy of drug delivery systems.

Macromolecular Nano-Assemblies for Enhancing the Effect of Oxygen-Dependent Photodynamic Therapy Against Hypoxic Tumors

In oxygen (O2)-dependent photodynamic therapy (PDT), photosensitizers absorb light energy, which is then transferred to ambient O2 and subsequently generates cytotoxic singlet oxygen (1O2). Therefore, the availability of O2 and the utilization efficiency of generated 1O2 are two significant factors that influence the effectiveness of PDT. However, tumor microenvironments (TMEs) characterized by hypoxia and limited utilization efficiency of 1O2 resulting from its short half-life and short diffusion distance significantly restrict the applicability of PDT for hypoxic tumors. To address these challenges, numerous macromolecular nano-assemblies (MNAs) have been designed to relieve hypoxia, utilize hypoxia or enhance the utilization efficiency of 1O2. Herein, we provide a comprehensive review on recent advancements achieved with MNAs in enhancing the effectiveness of O2-dependent PDT against hypoxic tumors.

Dual drug-loaded metal-phenolic networks for targeted magnetic resonance imaging and synergistic chemo-chemodynamic therapy of breast cancer

The development of nanomedicines with simplified compositions and synergistic theranostic functionalities remains a great challenge. Herein, we develop a simple method to integrate both atovaquone (ATO, a mitochondrial inhibitor) and cisplatin within tannic acid (TA)-iron (Fe) networks coated with hyaluronic acid (HA) for targeted magnetic resonance (MR) imaging-guided chemo-chemodynamic synergistic therapy. The formed TFP@ATO-HA displayed good colloidal stability with a mean size of 95.5 nm, which could accumulate at tumor sites after circulation and be specifically taken up by metastatic 4T1 cells overexpressing CD44 receptors. In the tumor microenvironment, TFP@ATO-HA could release ATO/cisplatin and Fe3+ in a pH-responsive manner, deplete glutathione, and generate reactive oxygen species with endogenous H2O2 for chemodynamic therapy (CDT). Additionally, ATO could enhance chemotherapeutic efficacy by inhibiting mitochondrial respiration, relieving hypoxia, and amplifying the CDT effect by decreasing intracellular pH and elevating Fenton reaction efficiency. In vivo experiments demonstrated that TFP@ATO-HA could effectively inhibit tumor growth and suppress lung metastases without obvious systemic toxicity. Furthermore, TFP@ATO-HA exhibited a r1 relaxivity of 2.6 mM-1 s-1 and targeted MR imaging of 4T1 tumors. Dual drug-loaded metal-phenolic networks can be easily prepared and act as effective theranostic nanoplatforms for targeted MR imaging and synergistic chemo-chemodynamic therapy.

Exploring the effect of protein secondary structure on the solid state and physical stability of protein-based amorphous solid dispersions

Amorphous solid dispersions (ASDs) using proteins as carriers have emerged as a promising strategy for stabilizing amorphous drug molecules. Proteins possess diverse three-dimensional structures that significantly influence their own properties and may also impact the properties of ASDs. We prepared β-lactoglobulin (BLG) with different contents of β-sheet and α-helical secondary structures by initially dissolving BLG in different mixed solvents, containing different ratios of water, methanol/ethanol, and acetic acid, followed by spray drying of the solutions. Our findings revealed that an increase in α-helical content resulted in a decrease in the glass transition temperature (Tg) of the protein. Subsequently, we utilized the corresponding mixed solvents to dissolve both BLG and the model drug celecoxib (CEL), allowing the preparation of ASDs containing either β-sheet-rich or α-helix/random coil-rich BLG. Using spray drying, we successfully developed BLG-based ASDs with drug loadings ranging from 10 wt% to 90 wt%. At drug loadings below 40 wt%, samples prepared using both methods exhibited single-phase ASDs. However, heterogeneous systems formed when the drug loading exceeded 40 wt%. At higher drug loadings, physical stability assessments demonstrated that the α-helix/random coil-rich BLG structure exerted a more pronounced stabilizing effect on the drug-rich phase compared to the β-sheet-rich BLG. Overall, our results highlight the importance of considering protein secondary structure in the design of ASDs.

Ex vivo transdermal delivery of 3H-labelled atovaquone solid drug nanoparticles: a comparison of topical, intradermal injection and microneedle assisted administration

Inherent barrier properties of the skin impose significant challenges to the transdermal delivery of drugs to systemic circulation. Here, the ex vivo transdermal permeation and deposition of an anti-malarial prophylactic atovaquone solid drug nanoformulation is radiometrically evaluated following application of a solid microneedle format.

Mechanisms of Drug Solubility Enhancement Induced by β-Lactoglobulin-Based Amorphous Solid Dispersions

Protein-based amorphous solid dispersions (ASDs) have emerged as a promising approach for enhancing solubility in comparison to crystalline drugs. The dissolution behavior of protein-based amorphous solid dispersions (ASDs) was investigated in various pH media. ASDs of four poorly soluble model drugs with acidic (furosemide and indomethacin), basic (carvedilol), and neutral (celecoxib) properties were prepared by spray drying at 30 wt % drug loading with the protein β-lactoglobulin (BLG). The effect of spray-dried BLG (SD-BLG) solubility and protein binding ability with dissolved drugs in solution were investigated to retrieve the mechanisms governing the improvement of drug solubility from the BLG-based ASDs. Powder dissolution results showed that all ASDs obtained a higher maximum concentration (Cmax) compared to the respective pure crystalline drugs. It was found that the solubility increase of the drugs from the ASDs was to a large extent dependent on the solubility of the pure SD-BLG at the investigated pH values (low solubility at pH near the isoelectric point (pI) of BLG). Furthermore, drug-protein interactions in a solution were observed, in particular at pH values where the drugs were neutral. These drug-protein interactions also resulted, to some extent, in the stabilization of the drug in supersaturation.

A Review on Physicochemical Properties of Polymers Used as Filaments in 3D-Printed Tablets

Three-dimensional (3D) printing technology has presently been explored widely in the field of pharmaceutical research to produce various conventional as well as novel dosage forms such as tablets, capsules, oral films, pellets, subcutaneous implants, scaffolds, and vaginal rings. The use of this innovative method is a good choice for its advanced technologies and the ability to make tailored medicine specifically for individual patient. There are many 3D printing systems that are used to print tablets, implants, and vaginal rings. Among the available systems, the fused deposition modeling (FDM) is widely utilized. The FDM has been regarded as the best choice of printer as it shows high potential in the production of tablets as a unit dose in 3D printing medicine manufacturing. In order to design a 3D-printed tablet or other dosage forms, the physicochemical properties of polymers play a vital role. One should have proper knowledge about the polymer's properties so that one can select appropriate polymers in order to design 3D-printed dosage form. This review highlighted the various physicochemical properties of polymers that are currently used as filaments in 3D printing. In this manuscript, the authors also discussed various systems that are currently adopted in the 3D printing.

Lipid-based solubilization technology via hot melt extrusion: promises and challenges

INTRODUCTION

Self-emulsifying drug delivery systems (SEDDS) are a promising strategy to improve the oral bioavailability of poorly water-soluble drugs (PWSD). The excipients of SEDDS enable permeation through the mucus and gastro-intestinal barrier, inhibiting efflux transporters (e.g. P-glycoprotein) of drugs. Poor drug loading capacity and formulation instability are the main setbacks of traditional SEDDS. The use of polymeric precipitation inhibitors was shown to create supersaturable SEDDS with increased drug payload, and their solidification can help to overcome the instability challenge. As an alternative to several existing SEDDS solidification technologies, hot melt extrusion (HME) holds the potential for lean and continuous manufacturing of supersaturable solid-SEDDS. Despite being ubiquitously applied in solid lipid and polymeric processing, HME has not yet been widely considered for the preparation of SEDDS.

AREAS COVERED

The review begins with the rationale why SEDDS as the preferred lipid-based delivery systems (LBDS) is suitable for the oral delivery of PWSD and discusses the common barriers to oral administration. The potential of LBDS to surmount them is discussed. SEDDS as the flagship of LBDS for PWSD is proposed with a special emphasis on solid-SEDDS. Finally, the opportunities and challenges of HME from the lipid-based excipient (LBE) processing and product performance standpoint are highlighted.

EXPERT OPINION

HME can be a continuous, solvent-free, cost-effective, and scalable technology for manufacturing solid supersaturable SEDDS. Several critical formulations and process parameters in successfully preparing SEDDS via HME are identified.

Supersaturation-Based Drug Delivery Systems: Strategy for Bioavailability Enhancement of Poorly Water-Soluble Drugs

At present, the majority of APIs synthesized today remain challenging tasks for formulation development. Many technologies are being utilized or explored for enhancing solubility, such as chemical modification, novel drug delivery systems (microemulsions, nanoparticles, liposomes, etc.), salt formation, and many more. One promising avenue attaining attention presently is supersaturated drug delivery systems. When exposed to gastrointestinal fluids, drug concentration exceeds equilibrium solubility and a supersaturation state is maintained long enough to be absorbed, enhancing bioavailability. In this review, the latest developments in supersaturated drug delivery systems are addressed in depth.

Cellulose derivatives as effective recrystallization inhibitor for ternary ritonavir solid dispersions: In vitro-in vivo evaluation

Amorphous solid dispersions (ASDs) are regarded as one of the most promising techniques for poorly-soluble active pharmaceutical ingredients (API). However, the thermodynamic instability of ASDs at supersaturated state makes them easy to recrystallize in aqueous media. In this study, ritonavir (RTV) was selected as a model drug for evaluating the solubility enhancement and recrystallization inhibition effect of various cellulose derivatives and the combinations of them with typical surfactants. Combination of HPMCAS-HF/SLS was filtrated for preparing ternary RTV solid dispersions (RTV SD) via solvent evaporation method. RTV SD exhibited enhanced dissolution manner, while the oral bioavailability of RTV SD was equivalent with the Reference Standard Norvir® but increased significantly compared to the ternary physical mixture. Thus, the ternary SD system might be promisingly employed as efficient drug delivery system for RTV, while the HPMCAS-HF/SLS combination could be recommended as effective excipient for fabricating steady solid dispersions loading poorly soluble API.

Coupling hot melt extrusion and fused deposition modeling: Critical properties for successful performance

Interest in 3D printing for pharmaceutical applications has increased in recent years. Compared to other 3D printing techniques, hot melt extrusion (HME)-based fused deposition modeling (FDM) 3D printing has been the most extensively investigated for patient-focused dosage. HME technology can be coupled with FDM 3D printing as a continuous manufacturing process. However, the crucial pharmaceutical polymers, formulation and process parameters must be investigated to establish HME-coupled FDM 3D printing. These advancements will lead the way towards developing continuous drug delivery systems for personalized therapy. This brief overview classifies pharmaceutical additive manufacturing, Hot Melt Extrusion, and Fused Deposition Modeling 3D printing techniques with a focus on coupling HME and FDM 3D printing processes. It also provides insights on the critical material properties, process and equipment parameters and limitations of successful HME-coupled FDM systems.

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.

Mechanisms of increased bioavailability through amorphous solid dispersions: a review

Amorphous solid dispersions (ASDs) can increase the oral bioavailability of poorly soluble drugs. However, their use in drug development is comparably rare due to a lack of basic understanding of mechanisms governing drug liberation and absorption in vivo. Furthermore, the lack of a unified nomenclature hampers the interpretation and classification of research data. In this review, we therefore summarize and conceptualize mechanisms covering the dissolution of ASDs, formation of supersaturated ASD solutions, factors responsible for solution stabilization, drug uptake from ASD solutions, and drug distribution within these complex systems as well as effects of excipients. Furthermore, we discuss the importance of these findings on the development of ASDs. This improved overall understanding of these mechanisms will facilitate a rational ASD formulation development and will serve as a basis for further mechanistic research on drug delivery by ASDs.

Implantable Medical Devices and Tissue Engineering: An Overview of Manufacturing Processes and the Use of Polymeric Matrices for Manufacturing and Coating their Surfaces

Medical devices are important diagnosis and therapy tools for several diseases which include a wide range of products. Technological advances in this area have been proposed to reduce adverse complication incidences. New technologies and manufacturing processes, as well as the development of new materials or medical devices with modified surface and the use of biodegradable polymeric devices such as a substrate for cell culture in the field of tissue engineering, have attracted considerable attention in recent years by the scientific community intended to produce medical devices with superior properties and morphology. This review article focused on implantable devices, addresses the major advances in the biomedical field related to the devices manufacture processes such as 3D printing and hot melting extrusion, and the use of polymer matrices composed of copolymers, blends, nanocomposites or grafted with antiproliferative drugs for manufacturing and/or coating the devices surface.

An update on the contribution of hot-melt extrusion technology to novel drug delivery in the twenty-first century: part I

INTRODUCTION

Currently, hot melt extrusion (HME) is a promising technology in the pharmaceutical industry, as evidenced by its application to manufacture various FDA-approved commercial products in the market. HME is extensively researched for enhancing the solubility and bioavailability of poor water-soluble drugs, taste masking, and modifying release in drug delivery systems. Additionally, its other novel opportunities or pharmaceutical applications, and capability for continuous manufacturing are being investigated. This efficient, industrially scalable, solvent-free, continuous process can be easily automated and coupled with other novel platforms for continuous manufacturing of pharmaceutical products.

AREAS COVERED

This review focuses on updates on solubility enhancement of poorly water-soluble drugs and process analytical tools such as UV/visible spectrophotometry; near-infrared spectroscopy; Raman spectroscopy; and rheometry for continuous manufacturing, with a special emphasis on fused deposition modeling 3D printing.

EXPERT OPINION

The strengths, weakness, opportunities, threats (SWOT) and availability of commercial products confirmed wide HME applicability in pharmaceutical research. Increased interest in continuous manufacturing processes makes HME a promising strategy for this application. However, there is a need for extensive research using process analytical tools to establish HME as a dependable continuous manufacturing process.

Feasibility of Using Gluconolactone, Trehalose and Hydroxy-Propyl Gamma Cyclodextrin to Enhance Bendroflumethiazide Dissolution Using Lyophilisation and Physical Mixing Techniques

Purpose: Hydrophobic drugs are facing a major challenge in dissolution rate enhancement and solubility in aqueous solutions; therefore, a variety of methods have been used to improve dissolution rate and/or solubility of bendroflumethiazide as a model hydrophobic drug. Methods: In this study, two main methods (physical mixing and lyophilisation) were used with gluconolactone, hydroxyl propyl γ-ccyclodextrin, and trehalose to explore this challenge. Bendroflumethiazide, practically insoluble in water, was mixed with one of the three excipients gluconolactone, hydroxyl propyl γ-cyclodextrin, and trehalose in three different ratios 1:1, 1:2, 1:5. To the best of our knowledge, the dissolution of the drug has not been previously enhanced by using either these methods or any of the used excipients. Samples containing drug and each of the excipients were characterized via dissolution testing, Fourier Transform infra-red spectroscopy, differential scanning calorimetry, and scanning electron microscopy. Results: The used methods showed a significant enhancement in dug dissolution rate; physical mixing significantly, p < 0.05, increased the percentage of the drug released with time; for example, bendroflumethiazide dissolution in distilled water was improved from less than 20% to 99.79% within 90 min for physically mixed drug-cyclodextrin 1:5. The lyophilisation process was enhanced and the drug dissolution rate and the highest drug dissolution was achieved for (drug-gluconolactone 1:1) with 98.98% drug release within 90 min. Conclusions: the physical mixing and freeze drying processes significantly increased the percentage of drug release with time.

Melt extrusion with poorly soluble drugs - An integrated review

Over the last few decades, hot melt extrusion (HME) has emerged as a successful technology for a broad spectrum of applications in the pharmaceutical industry. As indicated by multiple publications and patents, HME is mainly used for the enhancement of solubility and bioavailability of poorly soluble drugs. This review is focused on the recent reports on the solubility enhancement via HME and provides an update for the manufacturing/scaling up aspects of melt extrusion. In addition, drug characterization methods and dissolution studies are discussed. The application of process analytical technology (PAT) tools and use of HME as a continuous manufacturing process may shorten the drug development process; as a result, the latter is becoming the most widely utilized technique in the pharmaceutical industry. The advantages, disadvantages, and practical applications of various PAT tools such as near and mid-infrared, ultraviolet/visible, fluorescence, and Raman spectroscopies are summarized, and the characteristics of other techniques are briefly discussed. Overall, this review also provides an outline for the currently marketed products and analyzes the strengths, weaknesses, opportunities and threats of HME application in the pharmaceutical industry.