Development of ibuprofen dry suspensions by hot melt extrusion: Characterization, physical stability and pharmacokinetic studies

Microencapsulation for Pharmaceutical Applications: A Review

In order to improve bioavailability, stability, control release, and target delivery of active pharmaceutical ingredients (APIs), as well as to mask their bitter taste, to increase their efficacy, and to minimize their side effects, a variety of microencapsulation (including nanoencapsulation, particle size <100 nm) technologies have been widely used in the pharmaceutical industry. Commonly used microencapsulation technologies are emulsion, coacervation, extrusion, spray drying, freeze-drying, molecular inclusion, microbubbles and microsponge, fluidized bed coating, supercritical fluid encapsulation, electro spinning/spray, and polymerization. In this review, APIs are categorized by their molecular complexity: small APIs (compounds with low molecular weight, like Aspirin, Ibuprofen, and Cannabidiol), medium APIs (compounds with medium molecular weight like insulin, peptides, and nucleic acids), and living microorganisms (such as probiotics, bacteria, and bacteriophages). This article provides an overview of these microencapsulation technologies including their processes, matrix, and their recent applications in microencapsulation of APIs. Furthermore, the advantages and disadvantages of these common microencapsulation technologies in terms of improving the efficacy of APIs for pharmaceutical treatments are comprehensively analyzed. The objective is to summarize the most recent progresses on microencapsulation of APIs for enhancing their bioavailability, control release, target delivery, masking their bitter taste and stability, and thus increasing their efficacy and minimizing their side effects. At the end, future perspectives on microencapsulation for pharmaceutical applications are highlighted.

Novel Glyceryl Monostearate- and Polyethylene Glycol 6000-Based Ibuprofen Pellets Prepared by Hot-Melt Extrusion: Evaluation and Stability Assessment

Purpose

To prepare stable sustained-release (SR) pellets, containing high ibuprofen (IBU) loading, by hot-melt extrusion (HME) technique using polyethylene glycol 6000 (PEG 6000) and glyceryl monostearate (GMS).

Methods

HME pellets (60% w/w IBU) were prepared using PEG 6000, GMS, and mixture of both polymers (1:1). Stability studies were performed under stress conditions (40 °C and relative humidity “RH” of 75%) for 6 months and at room temperature for 12 months. Fresh and stored IBU pellets were evaluated by drug content (HPLC), release rate study (USP apparatus IV), DSC, and XRD.

Results

HME succeeded to produce SR-IBU pellets with high drug loading. PEG 6000 gave higher IBU release rate and relatively unstable formula after storage. PEG 6000/GMS mixture gave prolonged IBU release up to 4 h with stable formula for 12 months at room temperature. While, IBU/GMS pellets gave SR profile up to 6 h and a stable formula under both testing conditions. These advantages of IBU/GMS pellets could be an excellent candidate for SR-IBU product. DSC and XRD analysis data (enthalpy and counts) for IBU and polymers gave a mirror image for IBU release profiles of the studied HME pellets, for both fresh and stored samples.

Conclusion

Stable SR-IBU/GMS HME pellets with high IBU loading (60% w/w) were successfully produced, for the first time, without any other excipients.

Improved Bioavailability of Poorly Water-Soluble Drug by Targeting Increased Absorption through Solubility Enhancement and Precipitation Inhibition

Itraconazole (ITZ) is a class II drug according to the biopharmaceutical classification system. Its solubility is pH 3-dependent, and it is poorly water-soluble. Its pKa is 3.7, which makes it a weak base drug. The aim of this study was to prepare solid dispersion (SD) pellets to enhance the release of ITZ into the gastrointestinal environment using hot-melt extrusion (HME) technology and a pelletizer. The pellets were then filled into capsules and evaluated in vitro and in vivo. The ITZ changed from a crystalline state to an amorphous state during the HME process, as determined using DSC and PXRD. In addition, its release into the gastrointestinal tract was enhanced, as was the level of ITZ recrystallization, which was lower than the marketed drug (Sporanox^®), as assessed using an in vitro method. In the in vivo study that was carried out in rats, the AUC_0-48h of the commercial formulation, Sporanox^®, was 1073.9 ± 314.7 ng·h·mL^-1, and the bioavailability of the SD pellet (2969.7 ± 720.6 ng·h·mL^-1) was three-fold higher than that of Sporanox^® (*** p < 0.001). The results of the in vivo test in beagle dogs revealed that the AUC_0-24h of the SD-1 pellet (which was designed to enhance drug release into gastric fluids) was 3.37 ± 3.28 μg·h·mL^-1 and that of the SD-2 pellet (which was designed to enhance drug release in intestinal fluids) was 7.50 ± 4.50 μg·h·mL^-1. The AUC of the SD-2 pellet was 2.2 times higher than that of the SD-1 pellet. Based on pharmacokinetic data, ITZ would exist in a supersaturated state in the area of drug absorption. These results indicated that the absorption area is critical for improving the bioavailability of ITZ. Consequently, the bioavailability of ITZ could be improved by inhibiting precipitation in the absorption area.

Eudragit®: A Versatile Family of Polymers for Hot Melt Extrusion and 3D Printing Processes in Pharmaceutics

Eudragit® polymers are polymethacrylates highly used in pharmaceutics for the development of modified drug delivery systems. They are widely known due to their versatility with regards to chemical composition, solubility, and swelling properties. Moreover, Eudragit polymers are thermoplastic, and their use has been boosted in some production processes, such as hot melt extrusion (HME) and fused deposition modelling 3D printing, among other 3D printing techniques. Therefore, this review covers the studies using Eudragit polymers in the development of drug delivery systems produced by HME and 3D printing techniques over the last 10 years. Eudragit E has been the most used among them, mostly to formulate immediate release systems or as a taste-masker agent. On the other hand, Eudragit RS and Eudragit L100-55 have mainly been used to produce controlled and delayed release systems, respectively. The use of Eudragit polymers in these processes has frequently been devoted to producing solid dispersions and/or to prepare filaments to be 3D printed in different dosage forms. In this review, we highlight the countless possibilities offered by Eudragit polymers in HME and 3D printing, whether alone or in blends, discussing their prominence in the development of innovative modified drug release systems.

Impact of the manufacturing technique on the dissolution-enhancement functionality of PEG4000 in Cilostazol tablets

Cilostazol was selected as poorly-soluble model drug to investigate the impact of the manufacturing method on the excipient functionality of PEG4000 at various levels. Powder blends were prepared by direct compression (DC), wet granulation (WG) and hot-melt extrusion (HME). Characteristics of these blends and their compressed tablets were investigated by standard techniques. Solid-state characterization was carried out using differential scanning calorimetry (DSC). While DC trials were found with no significant differences, WG and HME showed contrasting enhancement and retardation effects regarding the dissolution profile of Cilostazol tablets depending on the level of PEG4000 incorporated. The optimal enhancement of dissolution was obtained at 10% w/w PEG4000 for tablets prepared by HME. DSC analysis indicated that no solid solutions were formed at such low levels of PEG4000during processing by either manufacturing techniques. Consequently, the wetting functionality and dissolution enhancement of PEG4000 was revealed to be level- and manufacturing method dependent.