Dissolution enhancement of poorly water-soluble APIs processed by hot-melt extrusion using hydrophilic polymers

Liquid API feeding in pharmaceutical HME: Novel options in solid dosage manufacturing

Hot melt extrusion (HME) is a common unit operation. It is broadly applicable in the pharmaceutical industry and can be implemented in a continuous manufacturing line. However, the conventional way of active pharmaceutical ingredient (API) feeding with a pre-blend consisting of a powdered API and a polymer does not allow the flexibility and agility to adjust the process parameters, which is generally an essential part of continuous manufacturing. In addition, this method of API feeding may result in the segregation of the individual powder components or agglomeration of highly cohesive materials, leading to an inhomogeneous API content in the extrudates, especially at low doses. In this study, the universal applicability of liquid side feeding in pharmaceutical HME was demonstrated using various APIs suspended or dissolved in water and fed as suspension or undersaturated, supersaturated, and highly concentrated solutions into anterior parts of the extruder. The extrudates were characterized in terms of their API content, residual moisture content, and solid-state of the API embedded in the polymer. The results show that a uniform API content without major deviations can be obtained via this method. Furthermore, the residual moisture content of the extrudates was low enough to have no significant influence on further processing of the final dosage form. In summary, this advanced way of feeding allows an accurate, flexible, and agile feeding of APIs, facilitating the production of personalized final dosage forms and a novel option to link the manufacturing of the drug substance and the drug product.

3D Printing of Personalised Carvedilol Tablets Using Selective Laser Sintering

Selective laser sintering (SLS) has drawn attention for the fabrication of three-dimensional oral dosage forms due to the plurality of drug formulations that can be processed. The aim of this work was to employ SLS with a CO2 laser for the manufacturing of carvedilol personalised dosage forms of various strengths. Carvedilol (CVD) and vinylpyrrolidone-vinyl acetate copolymer (Kollidon VA64) blends of various ratios were sintered to produce CVD tablets of 3.125, 6.25, and 12.5 mg. The tuning of the SLS processing laser intensity parameter improved printability and impacted the tablet hardness, friability, CVD dissolution rate, and the total amount of drug released. Physicochemical characterization showed the presence of CVD in the amorphous state. X-ray micro-CT analysis demonstrated that the applied CO2 intensity affected the total tablet porosity, which was reduced with increased laser intensity. The study demonstrated that SLS is a suitable technology for the development of personalised medicines that meet the required specifications and patient needs.

The Effect of Hot-Melt Extrusion of Mulberry Leaf on the Number of Active Compounds and Antioxidant Activity

The aim of this study is to compare the functions of the physiologically active compounds of three types of mulberry leaf by cultivar, and to confirm the changes using hot-melt extrusion (HME-ML). The active components of mulberry leaf were analyzed using the HPLC system, and total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity were measured. Among the three varieties, the highest contents of rutin and isoquercetin were detected in Cheongil, of TPC in Cheongol, and of TFC in Cheongil. It was confirmed that this bio-accessibility was increased in HME-ML compared with the control. The DPPH radical scavenging activity of Cheongol showed greater antioxidant properties, and HME showed improvement in the antioxidant properties of all mulberry leaves. These results suggest that the application of HME technology can improve the biological activities of mulberry leaf.

Optimization of mechanically assisted coamorphous dispersion extraction of hydrophobic compounds from plant tea (Citri Reticulatae Pericarpium) using water

This study aimed to establish a novel mechanically assisted coamorphous dispersion extraction (MADE) method for the extraction of hydrophobic compounds (hesperidin, nobiletin and tangeretin) from Citri Reticulatae Pericarpium using water. The surface morphology, particle size distributions, phase states and functional groups of the coground product surface were characterized by Scanning Electron Microscopy, X-ray diffraction and Fourier transform infrared spectroscopy. The parameters affecting the efficiency of extraction method were optimized by single-factor experiments and response surface methodology. The method showed good linear relationships in the range of 1-500 μg/mL with correlation coefficients (R²) ≥ 0.9990, low limits of detection ranging from 3.0 to 28.3 ng/mL, and acceptable recoveries ranging from 87.0 to 91.0%. Therefore, the proposed MADE method is a promising, efficient and organic solvent-free method for the extraction of hydrophobic compounds from plant tea.

Liquid and Solid Functional Bio-Based Coatings

The development of new bio-based coating materials to be applied on cellulosic and plastic based substrates, with improved performances compared to currently available products and at the same time with improved sustainable end of life options, is a challenge of our times. Enabling cellulose or bioplastics with proper functional coatings, based on biopolymer and functional materials deriving from agro-food waste streams, will improve their performance, allowing them to effectively replace fossil products in the personal care, tableware and food packaging sectors. To achieve these challenging objectives some molecules can be used in wet or solid coating formulations, e.g., cutin as a hydrophobic water- and grease-repellent coating, polysaccharides such as chitosan-chitin as an antimicrobial coating, and proteins as a gas barrier. This review collects the available knowledge on functional coatings with a focus on the raw materials used and methods of dispersion/application. It considers, in addition, the correlation with the desired final properties of the applied coatings, thus discussing their potential.

Preparation of Solid Dispersions of Simvastatin and Soluplus Using a Single-Step Organic Solvent-Free Supercritical Fluid Process for the Drug Solubility and Dissolution Rate Enhancement

The study was designed to investigate the feasibility of supercritical carbon dioxide (scCO₂) processing for the preparation of simvastatin (SIM) solid dispersions (SDs) in Soluplus^® (SOL) at temperatures below polymer’s glass transition. The SIM content in the SDs experimental design was kept at 10, 20 and 30% to study the effect of the drug–polymer ratio on the successful preparation of SDs. The SIM–SOL formulations, physical mixtures (PMs) and SDs were evaluated using X-ray diffraction (XRD), differential scanning calorimetry (DSC), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), and dissolution studies. The scCO₂ processing conditions and drug–polymer ratio were found to influence the physicochemical properties of the drug in formulated SDs. SIM is a highly crystalline drug; however, physicochemical characterisation carried out by SEM, DSC, and XRD demonstrated the presence of SIM in amorphous nature within the SDs. The SIM–SOL SDs showed enhanced drug dissolution rates, with 100% being released within 45 min. Moreover, the drug dissolution from SDs was faster and higher in comparison to PMs. In conclusion, this study shows that SIM–SOL dispersions can be successfully prepared using a solvent-free supercritical fluid process to enhance dissolution rate of the drug.

Novel tip-loaded dissolving and implantable microneedle array patches for sustained release of finasteride

Finasteride (FND) is a competitive inhibitor of 5α-reductase, an enzyme involved in benign prostatic hyperplasia (BPH) and androgenic alopecia. FND is administered in oral, often lifelong treatments, increasing the pill burden of polymedicated patients. Microneedle array patches (MAPs) are minimally invasive devices that painlessly pierce the outermost layers of the skin, forming slowly-dissolving drug depots in the dermis, which can release drugs over weeks or months, making this platform an attractive, patient-friendly option for long-term treatments. This work describes the development of long-acting dissolving and implantable PLGA MAPs aimed for systemic release of FND for at least two weeks. Mechanically strong tip-loaded MAPs with pyramidal geometry were obtained using micromoulding methodology. In vitro studies revealed that the dissolving and implantable MAPs were able to release the drug for over 7 and 14 days, respectively. Skin deposition experiments in Franz cells demonstrated that after 24 h, dissolving and implantable MAPs were able to deposit 629.00 ± 214.54 μg and 1861.64 ± 383.30 μg of FND in the skin, respectively. On the other hand, transdermal permeation studies showed that both formulations produced a slow release of the drug to the receptor compartment of the Franz cells, with dissolving and implantable MAPs releasing 90.43 ± 6.20 μg and 27.80 ± 3.94 μg of FND after 24 h. The formulations described here could be an alternative to current oral treatments, having the potential to deliver the drug for extended periods, simplifying the treatment of BPH and androgenic alopecia.

Towards predicting the product quality in hot-melt extrusion: Pilot plant scale extrusion

Following our study on the impact of hot melt extrusion (HME) process conditions on the product quality, we expanded our investigation to assessing the effect of scale-up on the product quality. To this end, we studied the influence of process settings and different scale-up variants on the active pharmaceutical ingredient (API) degradation in a pilot plant scale extruder. Six scale-up variants were investigated and none of them could replicate the product quality from the original process setup on a lab-scale extruder. By analyzing several process-dependent and -independent variables and cross referencing them to the experiments in the lab-scale extruder, we identified certain patterns. The results of the reduced order mechanistic 1D HME simulation of various process states made it possible to establish a correlation between the achieved API degradation and the local melt temperature and the exposure time in specific zones along the screw configuration. Since the same melt temperature and exposure time correlations were also valid for the lab scale-extruder, such an approach could be used in the future to predict the product quality as a function of processing conditions fully in silico prior to the first extrusion trials.

Enhancing the Cannabidiol (CBD) Compound in Formulated Hemp (Cannabis sativa L.) Leaves through the Application of Hot-Melt Extrusion

Cannabidiol (CBD) is a non-psychoactive cannabinoid compound found in hemp plants that has recently sparked interest in the biomedical and food industries. CBD is a natural decarboxylated product of cannabidiolic acid (CBDA). In this study, processing parameters were developed to enhance the decarboxylation process of CBDA in hemp leaves using hot-melt extrusion (HME). The hemp leaves were formulated with two different acid-based polymers, namely ascorbic acid (AA) and ascorbyl palmitate (AP), before the HME. The results showed that the carboxylation process of CBDA was increased by at least 2.5 times in the extrudate leaves and the content of the CBD was four times higher when formulated with AP (2800 µg/g) compared with the raw leaves (736 µg/g). The total phenolic and total flavonoid content, as well as the DPPH antioxidant capacity, were higher in the AP formulated extrudate. At the same time, the Δ9-tetrahydrocannabinol (THC) content was reduced by half in the extrudate compared with the raw leaves. It was also observed that double HME processing did not increase the decarboxylation process. It was concluded that the HME process significantly improved the conversion rate of CBDA to CBD in formulated hemp leaves with a reduced THC content.

Quaternary enteric solid dispersion prepared by hot-melt extrusion to mask the bitter taste and enhance drug stability

To mask the bitterness of drug is profoundly important especially in children's medication. This study designed and investigated a quaternary enteric solid dispersion (QESD) by secondary hot-melt-extrusion. Erythromycin (EM) was chosen as a model drug. The optimal QESD contained enteric polymer HPMCP-55, plasticizer and water-soluble polymer copovidone VA64. Raman and Atomic force microscope has exploited that majority EM was distributed in VA64 matrix, nanometer-sized EM-VA64 system was entrapped within enteric continuous phase to form a solid emulsion-like structure. For the prepared QESD, EM released concentration was far less than bitterness threshold (7 μg/mL to 20 μg/mL) in artificial saliva within the first 30 s. And dissolution rate was increased by 10% in article intestine fluid, which dominated by water-soluble VA64. Stress testing after two months at high-humidity (75% RH) and high-temperature (60 °C) revealed, compared with traditional enteric SDs, the chemical degradation of EM was slowed down in QESD. Furthermore, hydrogen and salt bonds were respectively formed between EM and VA64 and between leaking EM and HPMCP-55, which increasing the system stability and taste-masking. The effect of masking bitter taste can be satisfied as well as enhance drug dissolution rate in the intestine, and formulation physicochemical stability during storage.

Preparation, characterization and in-Vitro/in-Vivo evaluation of meloxicam extruded pellets with enhanced bioavailability and stability

OBJECTIVE

The present study involved enhancement of Meloxicam (MX) oral absorption for rapid onset of therapeutic action. A challenging approach using hot-melt-extrusion technique (HME) for production of stable novel preparation of MX pellets was successfully proposed.

METHODS

Manipulating HME processing parameters (barrel-temperatures and screw-speed) and proper polymer(s) selection (Soluplus, a combination of Soluplus/Poloxamar and Polyethylene Glycol 6000) were the main strategies involved for productive extrusion of MX. Evaluation of MX solid-state (TGA, DSC and PLM), absolute percent crystallinity, in-vitro dissolution (in acidic/aqueous pHs), and stability testing in accelerated conditions up to 6-months as well as a long-term shelf for 36-months were performed. A comparative bioavailability study of selected MX-Pellets was carried-out against the innovator product (Mobic^®) in 6 healthy volunteers under fed-conditions.

RESULTS

TGA, DSC and PLM analyses proved the dispersion of MX in amorphous-state within polymeric matrix by HME. MX/Soluplus pellets exhibited the lowest crystallinity % and best dissolution performance among other polymers in both pHs. In addition, presence of Soluplus safeguards final pellets stability under different storage conditions. MX rate of absorption (T_max) from Soluplus-based pellets attained a value of 45 min, which was 6-times faster than Mobic^® (4.5 hr).

CONCLUSION

A promising oral MX formula prepared by HME was successfully developed with a rapid onset of analgesic action (T_max of 45 mins; almost 2-times faster than reported intramuscular injection), hence appropriate in the early relief of pain associated with rheumatoid arthritis and osteoarthritis. Moreover, the proposed formula was physico-chemically stable up to 36 months of shelf-life storage.

Towards predicting the product quality in hot-melt extrusion: Small scale extrusion

In product development, it is crucial to choose the appropriate drug manufacturing route accurately and timely and to ensure that the technique selected is suitable for achieving the desired product quality. Guided by the QbD principles, the pharmaceutical industry is currently transitioning from batch to continuous manufacturing. In this context, process understanding and prediction are becoming even more important. With regard to hot melt extrusion, the process setup, optimization and scale-up in early stages of product development are particularly challenging due to poor process understanding, complex product-process relationship and a small amount of premix available for extensive experimental studies. Hence, automated, quick and reliable process setup and scale-up requires simulation tools that are accurate enough to capture the process and determine the product-process relationships. To this end, the effect of process settings on the degradation of the active pharmaceutical ingredient (API) in a lab-scale Leistritz ZSE12 extruder was investigated. As part of the presented study, the limitations of traditional process analysis using integral process values were investigated, together with the potential that simulations may have in predicting the process performance and the product quality. The results of our investigation indicate that the average melt temperatures and the exposure times in specific zones along the screw configuration correlate well with the API degradation values and can be used as potent process design criteria to simplify the process development.

Aqueous Dissolution and Dispersion Behavior of Polyvinylpyrrolidone Vinyl Acetate-based Amorphous Solid Dispersion of Ritonavir Prepared by Hot-Melt Extrusion with and without Added Surfactants

In this study, the lack of complete drug release from amorphous solid dispersions (ASDs), as observed in most published reports, was investigated. ASDs with 20% ritonavir were prepared by HME using polyvinylpyrrolidone vinyl acetate (PVPVA) alone and in combination with 10% poloxamer 407 or Span 20 as carriers. It was established by the film casting technique that ritonavir was molecularly dispersed in formulations, and accelerated stability testing confirmed that extrudates were physically stable. Dissolution of ASDs (100-mg ritonavir equivalent) was performed in 250 mL 0.01 N HCl (pH 2), pH 6.8 phosphate buffer and FeSSIF-V2. Drug concentrations were measured by filtration through 0.45-μm pores and in unfiltered media; the latter gave total amounts of drug present in dissolution media, both as solution and dispersion. Because of low solubility, ritonavir did not dissolve completely in aqueous media. Rather, it formed supersaturated solutions, and the excess drug dispersed in the oily amorphous form with low particle sizes that could crystallize with time. Due to higher drug solubility, the dissolved drug in FeSSIF-V2 was much higher than that in the phosphate buffer. Complete drug release could be observed by accounting for drug both in solution and as phase-separated dispersion. Thus, the present study provides a complete picture of in vitro drug dissolution and dispersion from ASDs.

Orodispersible Polymer Films with the Poorly Water-Soluble Drug, Olanzapine: Hot-Melt Pneumatic Extrusion for Single-Process 3D Printing

Amorphous solid dispersions (ASDs) improve the oral delivery of poorly water-soluble drugs. ASDs of olanzapine (OLZ), which have a high melting point and low solubility, are performed using a complicated process. Three-dimensional (3D) printing based on hot-melt pneumatic extrusion (HMPE) is a simplified method for producing ASDs. Unlike general 3D printing, printlet extrusion is possible without the preparation of drug-loaded filaments. By heating powder blends, direct fused deposition modeling (FDM) printing through a nozzle is possible, and this step produces ASDs of drugs. In this study, we developed orodispersible films (ODFs) loaded with OLZ as a poorly water-soluble drug. Various ratios of film-forming polymers and plasticizers were investigated to enhance the printability and optimize the printing temperature. Scanning electron microscopy (SEM) showed the surface morphology of the film for the optimization of the polymer carrier ratios. Differential scanning calorimetry (DSC) was used to evaluate thermal properties. Powder X-ray diffraction (PXRD) confirmed the physical form of the drug during printing. The 3D printed ODF formulations successfully loaded ASDs of OLZ using HMPE. Our ODFs showed fast disintegration patterns within 22 s, and rapidly dissolved and reached up to 88% dissolution within 5 min in the dissolution test. ODFs fabricated using HMPE in a single process of 3D printing increased the dissolution rates of the poorly water-soluble drug, which could be a suitable formulation for fast drug absorption. Moreover, this new technology showed prompt fabrication feasibility of various formulations and ASD formation of poorly water-soluble drugs as a single process. The immediate dissolution within a few minutes of ODFs with OLZ, an atypical antipsychotic, is preferred for drug compliance and administration convenience.

The Effect of Cooling on the Degree of Crystallinity, Solid-State Properties, and Dissolution Rate of Multi-Component Hot-Melt Extruded Solid Dispersions

: The effect of cooling on the degree of crystallinity, solid-state and dissolution properties of multi-component hot-melt extruded solid dispersions [SD] is of great interest for the successful formulation of amorphous SDs and is an area that is unreported, especially in the context of improving the stability of these specific systems. The thermal solid-state properties, degree of crystallinity, drug-polymer interactions, solubility and physical stability over time were investigated. X-ray powder diffraction [XRPD] and hyper differential scanning calorimetry [DSC] confirmed that indomethacin [INM] was converted to the amorphous state; however, the addition of poloxamer 407 [P407] had a significant effect on the degree of crystallinity and the solubility of the SD formulations. Spectroscopy studies identified the mechanism of interaction and solubility studies, showing a higher dissolution rate compared to amorphous and pure INM in pH 1.2 with a kinetic solubility of 20.63 µg/mL and 34.7 µg/mL after 3 and 24 h. XRPD confirmed that INM remained amorphous after 5 months stability testing in solid solutions with Poly(vinylpyrrolidone-co-vinyl acetate) [PVP VA64] and Plasdone S-630 [PL-S630]. Although cooling had a significant effect on the degree of crystallinity and on solubility of INM, the cooling method used did not have any significant effect on the amorphous stability of INM over time.

Development and Validation of an In-Line API Quantification Method Using AQbD Principles Based on UV-Vis Spectroscopy to Monitor and Optimise Continuous Hot Melt Extrusion Process

A key principle of developing a new medicine is that quality should be built in, with a thorough understanding of the product and the manufacturing process supported by appropriate process controls. Quality by design principles that have been established for the development of drug products/substances can equally be applied to the development of analytical procedures. This paper presents the development and validation of a quantitative method to predict the concentration of piroxicam in Kollidon^® VA 64 during hot melt extrusion using analytical quality by design principles. An analytical target profile was established for the piroxicam content and a novel in-line analytical procedure was developed using predictive models based on UV-Vis absorbance spectra collected during hot melt extrusion. Risks that impact the ability of the analytical procedure to measure piroxicam consistently were assessed using failure mode and effect analysis. The critical analytical attributes measured were colour (L* lightness, b* yellow to blue colour parameters—in-process critical quality attributes) that are linked to the ability to measure the API content and transmittance. The method validation was based on the accuracy profile strategy and ICH Q2(R1) validation criteria. The accuracy profile obtained with two validation sets showed that the 95% β-expectation tolerance limits for all piroxicam concentration levels analysed were within the combined trueness and precision acceptance limits set at ±5%. The method robustness was tested by evaluating the effects of screw speed (150–250 rpm) and feed rate (5–9 g/min) on piroxicam content around 15% w/w. In-line UV-Vis spectroscopy was shown to be a robust and practical PAT tool for monitoring the piroxicam content, a critical quality attribute in a pharmaceutical HME process.

Bio- Fortification of Angelica gigas Nakai Nano-Powder Using Bio-Polymer by Hot Melt Extrusion to Enhance the Bioaccessibility and Functionality of Nutraceutical Compounds

Angelica gigas Nakai (AGN) is a popular traditional herbal medicine which has been used to alleviate various human diseases in Korea since ancient times. However, the low bioaccessibility of the nutraceutical compounds of AGN results in a poor water solubility, thereby limiting bioavailability. In this regard, a ternary AGN-biopolymer-plasticizer composite (AGNC) was developed to enhance the bioaccessibility of nutraceutical compounds from extrudate AGN formulations manufactured by hot melt extrusion (HME). The AGNC was prepared with extrudate AGN (EAGN) using different hydroxypropyl methylcellulose (HPMC) biopolymers (5% w/w) viz.: hypromellose phthalate (HP), hypromellose (AN), and hypromellose (CN) along with acetic acid (AA) (0.1 M, 20% w/v) as a plasticizer. The non-extrudate fresh AGN (FAGN) powder was used as a control. The physicochemical properties of the extrudate formulations and control were characterized by differential scanning calorimetry (DSC) and Fourier-transform infrared spectroscopy (FTIR). DSC analysis showed a lower enthalpy (ΔH) (12.22 J/g) and lower glass transition temperature (Tg) (41 °C) in HP-AA-EAGN compared to the control. FTIR confirmed the physical crosslinking between AGN and biopolymer in the extrudate composite and demonstrated that some functional groups formed viz., -OH and -CH2. The obtained result also shows that the particle size was reduced by 341 nm, and solubility was increased by 65.5% in HP-AA-EAGN compared to the control (1499 nm, 29.4%, respectively). The bioaccessibility of the total phenolic content and the total flavonoids-including decursin (D) and decursinol angelate (DA)-were significantly higher in HP-AA-EAGN compared to the control. The 2,2-diphenyl-1 picryl hydrazyl (DPPH) free radical scavenging capacity and ferric reducing antioxidant power assay (FRAP) indicated that the HP-AA-EAGN formulation preserves a greater antioxidant profile than the other formulations. Finally, it is summarized that the addition of acidified HP biopolymer increased the bioaccessibility, functionality, and improved the physicochemical properties of nutraceutical compounds in the extrudate AGN formulation.

Evaluation of Dissolution Enhancement of Aprepitant Drug in Ternary Pharmaceutical Solid Dispersions with Soluplus® and Poloxamer 188 Prepared by Melt Mixing

In the present study Aprepitant (APT) ternary solid dispersions (SDs) were developed and evaluated for the first time. Specifically, ternary SDs of APT with Poloxamer 188 and Soluplus® (SOL) were prepared via melt mixing and compared to binary APT/Poloxamer 188 and APT/SOL SDs. Initially, combined thermo-gravimetric and hot-stage polarized light microscopy studies indicated that all tested compounds were thermally stable up to 280 °C, while Poloxamer 188 acted as a plasticizer to SOL by significantly reducing the temperature required to fully solubilize the API during SD preparation. Differential scanning calorimetry combined with wide angle X-ray diffraction studies showed that crystalline API was dispersed in both binary and ternary SDs, while Fourier transformation-infrared spectroscopy studies revealed no molecular interactions among the components. Scanning electron microscopy combined with EDAX element analysis showed that the API was dispersed in nano-scale within the polymer matrices, while increasing APT content led to increasing API nano-crystals within the SDs. Finally, dissolution studies showed that the prepared formulations enhanced dissolution of Aprepitant and its mechanism analysis was further studied. A mathematical model was also investigated to evaluate the drug release mechanism.

Multilayer-Coated Tablet of Clopidogrel and Rosuvastatin: Preparation and In Vitro/In vivo Characterization

The acid lability of rosuvastatin hinders the preparation of mixed combination formulations of rosuvastatin with acidic drugs such as clopidogrel. Therefore, the purpose of this study was to develop a multilayer-coated tablet that avoids physicochemical interactions between rosuvastatin and clopidogrel. Among the tested hydrophobic materials, glyceryl behenate was most effective at inhibiting the production of lactone, the acid degradation product of rosuvastatin. Therefore, the multilayer-coated tablet included a hydrophobic separation layer consisting of glyceryl behenate between the clopidogrel core tablet and the rosuvastatin coating layer. In order to prevent delayed dissolution by the stable hydrophobic separation layer, crospovidone was added into the clopidogrel core tablet as an effective disintegrant. Copovidone was also added to the coating layer of rosuvastatin, achieving a dissolution profile comparable to that of the reference drug, Crestor^®. The resulting multilayer-coated tablet exhibited similar pharmacokinetic profiles to those of reference drugs (Plavix^® and Crestor^®) in beagle dogs, and there was no statistically significant difference in the maximum plasma concentration (C_max), the time to reach the maximum plasma concentration (T_max), or the area under the plasma-concentration time curve (AUC) between the test and reference formulations. The storage stability tests showed that the amounts of acid degradation products and total impurities were comparable to that of the reference drug. In conclusion, the present study successfully developed a stable multilayer-coated tablet containing both clopidogrel and rosuvastatin that may improve the patient compliance in combination therapy for cardiovascular diseases.

Aprepitant Drug in Ternary Pharmaceutical Solid Dispersions with Soluplus® and Poloxamer 188 Prepared by Melt Mixing

In the present study Aprepitant (APT) ternary solid dispersions (SDs) were developed and evaluated for the first time. Specifically, ternary SDs of APT with Poloxamer 188 and Soluplus® (SOL) were prepared via melt mixing and compared to binary APT/Poloxamer 188 and APT/SOL SDs. Initially, combined thermo-gravimetric and hot-stage polarized light microscopy studies indicated that all tested compounds were thermally stable up to 280 °C, while Poloxamer 188 acted as a plasticizer to SOL by significantly reducing the temperature required to fully solubilize the API during SD preparation. Differential scanning calorimetry combined with wide angle X-ray diffraction studies showed that crystalline API was dispersed in both binary and ternary SDs, while Fourier transformation-infrared spectroscopy studies revealed no molecular interactions among the components. Scanning electron microscopy combined with EDAX element analysis showed that the API was dispersed in nano-scale within the polymer matrices, while increasing APT content led to increasing API nano-crystals within the SDs. Finally, dissolution studies showed that the prepared formulations enhanced dissolution of Aprepitant and its mechanism analysis was further studied. A mathematical model was also investigated to evaluate the drug release mechanism

Chemico-calorimetric analysis of amorphous granules manufactured via continuous granulation process

The current study explores the first case of the implementation of solution calorimetry (SolCal) in order to determine the amorphous content of crystalline benzoyl-methoxy-methylindol-acetic acid (BMA)-a model poorly soluble drug, in the amorphous granules prepared via single-step continuous twin-screw dry granulations (TSG). Amorphous magnesium aluminometasilicate (Neusilin®) (US2) was used as a novel inorganic carrier via a TwinLab 10 mm twin-screw extruder. The BMA/US2 blends were processed at 180 °C and varying drug: carrier ratios of 1:4, 1:2.5 and 1:1 (w/w). Physico-chemical characterisation conducted via SEM, DSC and XRPD showed amorphous state of the drug in all granulated formulations. Reverse optical microscopy revealed a meso-porous structure of US2 in which the drug particles are adsorbed and/or entrapped within the porous network of the carrier. This phenomenon can be the underlying reason for the increase of the amorphous content in the extruded granules. Solution calorimetry (SolCal) study revealed amorphous content of the drug in all formulations quite precisely, whereas the dynamic vapour sorption (DVS) analysis complemented the results from SolCal. Furthermore, an attempt has been made for the first time to interrelate the findings from the SolCal to that of the release of the drug from the amorphous granules. It can be concluded that SolCal can be used as a novel technique to precisely quantify and interrelate the amorphous content to its physico-chemical performances such as drug release from the granulated formulations processed via TSG.

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.

Processability of AquaSolve™ LG polymer by hot-melt extrusion: Effects of pressurized CO2 on physicomechanical properties and API stability

The objective of this study was to investigate the processability of AquaSolve™ hydroxypropyl methylcellulose acetate succinate L grade (HPMCAS LG) via hot-melt extrusion and to examine the effect of pressurized carbon dioxide (P-CO₂) on the physicomechanical properties of efavirenz (EFA)-loaded extrudates. To optimize the process parameters and formulations, various physical mixtures of EFA (30%, 40%, and 50%, w/w) and HPMCAS LG (70%, 60%, and 50%, w/w), respectively, were extruded using a co-rotating twin-screw extruder with a standard screw configuration, with P-CO₂ injected into zone 8 of the extruder. Thermal characterization of the extrudates was performed using differential scanning calorimetry and thermogravimetric analysis. Scanning electron microscopy was employed to study the morphology and porosity of the formulations. Notably, the macroscopic morphology changed to a foam-like structure by P-CO₂ injection resulting in an increased specific surface area, porosity, and dissolution rate. Thus, HPMCAS LG extrusion, coupled with P-CO₂ injection, yielded faster dissolving extrudates. Stability studies indicated that HPMCAS LG was able to physically and chemically stabilize the amorphous state of high-dose EFA. Furthermore, the milling efficiency of the extrudates produced with P-CO₂ injection improved because of their increased porosity.

Influence of Polymeric Additive on the Physical Stability and Viscoelastic Properties of Aripiprazole

In this article, we investigated aripiprazole + Kollidon VA64 (ARP/KVA) and aripiprazole + Soluplus (ARP/SOP) amorphous solid dispersions. Thermal properties of all prepared systems have been examined by means of differential scanning calorimetry (DSC). Compositions revealing the recrystallization tendency were subsequently investigated by means of broadband dielectric spectroscopy (BDS). On the basis of dielectric data, the physically stable drug-polymer concentrations have been found. Finally, these systems have been investigated by rheology, which enables us to determine the minimal temperature required for dissolving the drug in the polymeric matrix, as well as the temperature dependence of the sample viscosity. Our investigations have shown that the amorphous form of the investigated antipsychotic drug might be effectively stabilized by both employed polymers. However, due to the better stabilization effect and the more favorable rheological properties, KVA proved to be a better polymeric excipient for extrusion of amorphous aripiprazole.

Development of a Polymer-Mediated Soybean Nanocomposite by Hot Melt Extrusion to Improve Its Functionality and Antioxidant Properties

The poor bioaccessibility of the phenolic compounds of soybeans is a key challenge to developing functional food products. Therefore, a novel hydrophilic food-grade hydroxypropyl methylcellulose (HPMC) polymer was added to soybean to prepare a soybean food composite (SFC), in order to improve the soybean's functionality. The SFC was prepared with soybean (95%) plus HPMC (5%) (w/w) mixes (HSE), as well as 100% soybean extrudate (SE), at 80 °C and 130 °C by a hot melt extrusion (HME) process. A non-extrudate 100% soybean material was considered as a control. It is observed that water solubility was significantly increased (35.18%), and particle size reached to nano-size (171.5 nm) in HSE at 130 °C compared to the control (7.14% and 1166 nm, respectively). The total phenolic, flavonoid, and single isoflavones content, including daidzin, daidzein, glycitein, genistein, and genistin was significantly increased in HSE at 130 °C compared to the control. The antioxidant properties were also significantly increased in HSE at 130 °C compared to the control, measured by 2,2-diphenyl-1 picryl hydrazyl (DPPH), a ferric reducing antioxidant power assay (FRAP), and the phosphomolybdenum method (PPMD). Finally, it is concluded that the HPMC polymer could be used as a novel excipient to develop nanocomposite via HME, in order to improve the functionality of soybean food products.

Effects of Dendrimer-Like Biopolymers on Physical Stability of Amorphous Solid Dispersions and Drug Permeability Across Caco-2 Cell Monolayers

The potential applications of dendrimer-like biopolymers (DLB) as stabilizing excipients for amorphous solid dispersion (ASD) of niclosamide, celecoxib, and resveratrol were evaluated based on (1) the formation and physical stability of the ASD and (2) the permeability and flux of the agents across Caco-2 cell monolayers. The evaluation was made by comparing the performance of prototype phytoglycogen derivatives (DLB1, DLB2, and DLB3) with commonly used polymers such as HPMCAS, PVPVA, and Soluplus®. PXRD was used to confirm the formation of the dispersions and detect crystallinity peaks formed during 2- and 4-week storage at 40°C/75% RH. At concentrations below 2 g/mL, the viability of Caco-2 cells remained above 80% for all DLB samples compared to untreated cells in the MTT assay. Permeability studies revealed a repeating pattern in which an increase in the initial concentration (C₀) was associated with a concomitant decrease in the apparent permeability (P_app) which we theorize is due to differences in drug-polymer interactions. Niclosamide-DLB1 dispersion had the lowest flux due to a significant reduction in P_app. The high increase in the C₀ of celecoxib-DLB2, however, made up for the reduction in the P_app and produced the highest flux values compared to other polymers. Resveratrol-DLB3 had a 5× reduction in P_app, but C₀ increased from 25.8 to 176 μg/mL led to a higher flux compared to the crystalline drug without polymer. Collectively, these results provide a "proof-of-concept" basis to demonstrate that DLB excipients have the ability to increase apparent solubility (Sol_app), most likely due to drug-binding capacity.

Hot Melt Extrusion: Highlighting Physicochemical Factors to Be Investigated While Designing and Optimizing a Hot Melt Extrusion Process

Hot-melt extrusion (HME) is a well-accepted and extensively studied method for preparing numerous types of drug delivery systems and dosage forms. It offers several advantages: no solvents are required, it is easy to scale up and employ on the industrial level, and, in particular, it offers the possibility of improving drug bioavailability. HME involves the mixing of a drug with one or more excipients, in general polymers and even plasticizers, which can melt, often forming a solid dispersion of the drug in the polymer. The molten mass is extruded and cooled, giving rise to a solid material with designed properties. This process, which can be realized using different kinds of special equipment, may involve modifications in the drug physicochemical properties, such as chemical, thermal and mechanical characteristics thus affecting the drug physicochemical stability and bioavailability. During process optimization, the evaluation of the drug solid state and stability is thus of paramount importance to guarantee stable drug properties for the duration of the drug product shelf life. This manuscript reviews the most important physicochemical factors that should be investigated while designing and optimizing a hot melt extrusion process, and by extension, during the different pre-formulation, formulation and process, and post-formulation phases. It offers a comprehensive evaluation of the chemical and thermal stability of extrudates, the solid physical state of extrudates, possible drug-polymer interactions, the miscibility/solubility of the drug-polymer system, the rheological properties of extrudates, the physicomechanical properties of films produced by hot melt extrusion, and drug particle dissolution from extrudates. It draws upon the last ten years of research, extending inquiry as broadly as possible.

Immediate Release 3D-Printed Tablets Produced Via Fused Deposition Modeling of a Thermo-Sensitive Drug

PURPOSE

Dissolution speeds of tablets printed via Fused Deposition Modeling (FDM) so far are significantly lower compared to powder or granule pressed immediate release tablets. The aim of this work was to print an actual immediate release tablet by choosing suitable polymers and printing designs, also taking into account lower processing temperatures (below 100°C) owing to the used model drug pantoprazole sodium.

METHODS

Five different pharmaceutical grade polymers polyvinylpyrrolidone (PVP K12), polyethylene glycol 6000 (PEG 6000), Kollidon® VA64, polyethylene glycol 20,000 (PEG 20,000) and poloxamer 407 were successfully hot-melt-extruded to drug loaded filaments and printed to tablets at the required low temperatures.

RESULTS

Tablets with the polymers PEG 6000 and PVP K12 and with a proportion of 10% pantoprazole sodium (w/w) demonstrated a fast drug release that was completed within 29 min or 10 min, respectively. By reducing the infill rate of PVP tablets to 50% and thereby increase the tablet porosity it was even possible to reduce the mean time for total drug release to only 3 min.

CONCLUSIONS

The knowledge acquired through this work might be very beneficial for future FDM applications in the field of immediate release tablets especially with respect to thermo-sensitive drugs.

Investigation of Ethylene Oxide-co-propylene Oxide for Dissolution Enhancement of Hot-Melt Extruded Solid Dispersions

The optimal design of amorphous solid dispersion formulations requires the use of excipients to maintain supersaturation and improve physical stability to ensure shelf-life stability and better absorption during intestinal transit, respectively. Blends of excipients (surfactants and polymers) are often used within pharmaceutical products to improve the oral delivery of Biopharmaceutical Classification System class II drugs. Therefore, in this study, a dissolution enhancer, poloxamer 407 (P407), was investigated to determine its effect on the dissolution properties and on the amorphous nature of the active pharmaceutical ingredient contained in the formulation. Phase solubility studies of indomethacin (INM) in aqueous solutions of P407 and poly(vinylpyrrolidone-vinyl acetate copolymer) showed an increase in the kinetic solubility of INM compared with the pure drug at 37°C with a K_a value of 0.041 μg/mL. The solid dispersions showed a higher dissolution rate when compared to pure and amorphous drugs when performed in pH buffer 1.2 with a kinetic solubility of 21 μg/mL. The stability data showed that the amorphous drug in solid solutions with poly(vinylpyrrolidone-vinyl acetate copolymer) and P407 remained amorphous, and the %P407 loading had no effect on the amorphous stability of INM. This study concluded that the amorphous solid dispersion contributed to the increased solubility of INM.

Application of hot melt extrusion for improving bioavailability of artemisinin a thermolabile drug

Hot melt extrusion has been used to produce a solid dispersion of the thermolabile drug artemisinin. Formulation and process conditions were optimized prior to evaluation of dissolution and biopharmaceutical performance. Soluplus^®, a low T_g amphiphilic polymer especially designed for solid dispersions enabled melt extrusion at 110 °C although some drug-polymer incompatibility was observed. Addition of 5% citric acid as a pH modifier was found to suppress the degradation. The area under plasma concentration time curve (AUC_0-24h) and peak plasma concentration (C_max) were four times higher for the modified solid dispersion compared to that of pure artemisinin.

FDM 3D printing of modified drug-delivery systems using hot melt extrusion: a new approach for individualized therapy

The production process of 3D-printed drugs offers unique advantages such as the possibility of individualizing the drug therapy and easily associating different drugs and release technologies in the same pharmaceutical unit. Fused deposition modeling, a 3D printing technique, seems especially interesting for pharmaceutical applications, due to its low cost, precise and reproducible control of the printed structures, and versatility for industrial and laboratory scale. This technique combined with another technology already adapted for the pharmaceutical industry, the hot melt extrusion, is able to incorporate various mechanisms of modified drug release. This special report aims to bring together data of the experimental progress achieved using the fused deposition modeling 3D printing combined with hot melt extrusion technique and its potential in drug delivery.

[Formula: see text]

Characterization and pharmacokinetic study of itraconazole solid dispersions prepared by solvent-controlled precipitation and spray-dry methods

OBJECTIVES

Solid dispersion formulations have attracted attention to improve solubility and bioavailability of water-insoluble drugs. In this study, the variation of solubility and bioavailability by different preparation methods were studied using itraconazole (ITZ) solid dispersions.

METHODS

Itraconazole solid dispersions were prepared by a solvent-controlled precipitation method (SCPM) using HPMCAS-LF, HCl antisolvent or a spray-drying method (SDM) for comparison. Dissolution tests by pH transition and pharmacokinetic study using male Sprague Dawley rats were conducted.

KEY FINDINGS

Itraconazole solid dispersion dissolution tests by pH transition exhibited better dissolution compared to naive ITZ, limited dissolution in acidic conditions and a burst release at neutral pH. The ITZ solid dispersions by SCPM indicated a smaller-sized particle dispersion, limited dissolution at acidic pH and a higher release at neutral pH compared to those by SDM, suggesting that the increased protonation of anionic polymers and HPMCAS-LF by acidic antisolvent could form a tighter hydrophobic aggregation with ITZ in solid dispersions. ITZ solid dispersion prepared by SCPM also showed improved ITZ absorption in male Sprague Dawley rats compared to SDM and naïve ITZ.

CONCLUSIONS

This study suggests that the SCPM method can be widely used for solid dispersion preparations due to improved dissolution and PK profile.

Enhancing the oral bioavailability of biochanin A by encapsulation in mixed micelles containing Pluronic F127 and Plasdone S630

Biochanin A (BCA), a natural dietary isoflavone, has been reported to show anticancer activities. However, its low biological availability and poor aqueous solubility limit its usefulness as a chemotherapeutic agent. We developed BCA-loaded micelles with Pluronic F127 and Plasdone S630 (BCA-FS). The optimized, spherical-shaped BCA-FS was obtained at a ratio of 1:1 (F127:S630). The particle size was 25.17±1.2 nm, and the zeta potential was −10.9±0.24 mV. BCA solubility in water increased to 5.0 mg/mL after encapsulation, and the drug-loading efficiency was 5.88%±0.76%. In vitro release experiments showed a delayed release of BCA from the mixed micelles. Furthermore, the BCA absorption permeability across a Caco-2 cell monolayer from the apical side to the basolateral side increased by 54% in BCA-FS. A pharmacokinetics evaluation showed a 2.16-fold increase in the relative oral bioavailability of BCA-FS compared with raw BCA, indicating that the mixed micelles may promote absorption in the gastrointestinal tract. A gastrointestinal safety assay was used to assess the reliability and safety of BCA-FS. On the basis of these findings, we conclude that this simple nanomicelle system could be leveraged to deliver BCA and other hydrophobic drugs.

Preparation and Evaluation of Hot-Melt Extruded Patient-Centric Ketoprofen Mini-Tablets

BACKGROUND

Bitter tasting drugs represent a large portion of active pharmaceutical ingredients. Mini-tablets are specifically designed for patients with difficulty in swallowing particular in young children up to 10 years of age, geriatric patients and patients with esophagitis.

OBJECTIVE

The present study was aimed to prepare, taste-masked mini-tablets, which are easily swallowed dosage forms, primarily to be used by pediatric and geriatric patients.

METHODS

Ketoprofen (10%-50% w/w) and Eudragit® EPO were blended and extruded with a 5-mm strand die and cut into consistent mini-tablets by using an adapted downstream pelletizer.

RESULTS

Differential scanning calorimetry and polarized light microscopy-hot stage microscopy studies confirmed that the binary mixtures were miscible under the employed extrusion temperatures. In-vitro release studies showed that drug release was less than 0.5% within the first 2 min in simulated salivary fluid (pH 6.8) and more than 90% in the first 20 min in gastric media (pH 1.0). The results of the electronic tongue analysis were well correlated with the drug release profile of the mini-tablets in the artificial saliva. Scanning electron microscopy revealed no cracks on the surface of the minitablets, confirming that the mini-tablets were compact solids. Chemical imaging confirmed the uniform distribution of ketoprofen inside the polymer matrices.

CONCLUSION

Eudragit® EPO containing ketoprofen at various drug loads were successfully melt extruded into tastedmasked mini-tablets. The reduced drug release at salivary pH correlated well with Astree e-Tongue studies for taste masking efficiency.

Continuous manufacturing via hot-melt extrusion and scale up: regulatory matters

Currently, because globalization, the pharmaceutical industry is facing enormous challenges to comply with regulatory matters. Reduced patent life and overall decreased profitability of newly discovered drugs are also forcing the pharmaceutical industry to shorten the drug development time with maximum throughput. Therefore, continuous manufacturing (CM) processes via hot melt extrusion (HME) can be a promising alternative for achieving these goals. HME offers solvent-free green technology with a process that is easy to scale up. Moreover, CM provides better product quality assurance compared with batch processes, with fewer labor costs and shorter time to development. In this review, we primarily focus on various aspects of CM and the emerging application of HME to bridge the current manufacturing gap in pharmaceutical sphere.

Advanced surface chemical analysis of continuously manufactured drug loaded composite pellets

The aim of the present study was to develop and characterise polymeric composite pellets by means of continuous melt extrusion techniques. Powder blends of a steroid hormone (SH) as a model drug and either ethyl cellulose (EC N10 and EC P7 grades) or hydroxypropyl methylcellulose (HPMC AS grade) as polymeric carrier were extruded using a Pharma 11mm twin screw extruder in a continuous mode of operation to manufacture extruded composite pellets of 1mm length. Molecular modelling study using commercial Gaussian 09 software outlined a possible drug-polymer interaction in the molecular level to develop solid dispersions of the drug in the pellets. Solid-state analysis conducted via a differential scanning calorimetry (DSC), hot stage microscopy (HSM) and X-ray powder diffraction (XRPD) analyses revealed the amorphous state of the drug in the polymer matrices. Surface analysis using SEM/energy dispersive X-ray (EDX) of the produced pellets arguably showed a homogenous distribution of the C and O atoms in the pellet matrices. Moreover, advanced chemical surface analysis conducted via atomic force microscopy (AFM) showed a homogenous phase system having the drug molecule dispersed onto the amorphous matrices while Raman mapping confirmed the homogenous single-phase drug distribution in the manufactured composite pellets. Such composite pellets are expected to deliver multidisciplinary applications in drug delivery and medical sciences by e.g. modifying drug solubility/dissolutions or stabilizing the unstable drug (e.g. hormone, protein) in the composite network.

Development and optimization of ketoconazole oral strips by means of continuous hot-melt extrusion processing

Objectives

The aim of this study was to develop mucoadhesive oral strips using hot-melt extrusion as a continuous manufacturing process.

Methods

Powder blends of ketoconazole, a water-insoluble drug – either hydroxypropyl methylcellulose (HPMC) or soluplus (SOL), sorbitol (SRB) and magnesium aluminometasilicate (MAS) were extruded to manufacture thin strips with 0.5-mm thickness. The presence of the inorganic metasilicate facilitated smooth processing of the extruded strips as it worked as an absorbent directly impacting on the extensive mixing of the drug/excipients inside the extruder barrel.

Key findings

The use of MAS also favoured the rapid hydration, swelling and eventual disintegration of the strips. Differential scanning calorimetry and transmission X-ray diffraction analysis revealed the existence of the amorphous drug within the extruded strips. Scanning electron microscopy and energy dispersive X-ray undertaken on the formulations showed a homogeneous drug distribution within the extruded strips.

Conclusion

The strips produced via continuous hot-melt extrusion processing showed significantly faster release of ketoconazole compared to the bulk drug substance.

Novel Controlled Release Polymer-Lipid Formulations Processed by Hot Melt Extrusion

The aim of the study was to investigate the effect of novel polymer/lipid formulations on the dissolution rates of the water insoluble indomethacin (INM), co-processed by hot melt extrusion (HME). Formulations consisted of the hydrophilic hydroxypropyl methyl cellulose polymer (HPMCAS) and stearoyl macrogol-32 glycerides-Gelucire 50/13 (GLC) were processed with a twin screw extruder to produce solid dispersions. The extrudates characterized by X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC) and hot stage microscopy (HSM) indicated the presence of amorphous INM within the polymer/lipid matrices. In-line monitoring via near-infrared (NIR) spectroscopy revealed significant peak shifts indicating possible interactions and H-bonding formation between the drug and the polymer/lipid carriers. Furthermore, in vitro dissolution studies showed a synergistic effect of the polymer/lipid carrier with 2-h lag time in acidic media followed by enhanced INM dissolution rates at pH > 5.5.