Impact of Porous Excipients on the Manufacturability and Product Performance of Solid Self-Emulsifying Drug Delivery Systems

Comparison of two self-nanoemulsifying drug delivery systems using different solidification techniques for enhanced solubility and oral bioavailability of poorly water-soluble celecoxib

In this study, we aimed to develop a solid self-nanoemulsifying drug delivery system (S-SNEDDS) and a solid self-nanoemulsifying granule system (S-SNEGS) to enhance the solubility and oral bioavailability of celecoxib. This process involved the preparation of a liquid SNEDDS (L-SNEDDS) and its subsequent solidification into a S-SNEDDS and a S-SNEGS. The L-SNEDDS consisted of celecoxib (drug), Captex® 355 (Captex; oil), Tween® 80 (Tween 80; surfactant) and D-α-Tocopherol polyethylene glycol 1000 succinate (TPGS; cosurfactant) in a weight ratio of 3.5:25:60:15 to produce the smallest nanoemulsion droplet size. The S-SNEDDS and S-SNEGS were prepared with L-SNEDDS/Ca-silicate/Avicel PH 101 in a weight ratio of 103.5:50:0 using a spray dryer and 103.5:50:100 using a fluid bed granulator, respectively. We compared the two novel developed systems and celecoxib powder based on their solubility, dissolution rate, physicochemical properties, flow properties and oral bioavailability in rats. S-SNEGS showed a significant improvement in solubility and dissolution rate compared to S-SNEDDS and celecoxib powder. Both systems had been converted from crystalline drug to amorphous form. Furthermore, S-SNEGS exhibited a significantly reduced angle of repose, compressibility index and Hausner ratio than S-SNEDDS, suggesting that S-SNEGS was significantly superior in flow properties. Compared to S-SNEDDS and celecoxib powder, S-SNEGS increased the oral bioavailability (AUC value) in rats by 1.3 and 4.5-fold, respectively. Therefore, S-SNEGS wolud be recommended as a solid self-nanoemulsifying system suitable for poorly water-soluble celecoxib.

Quality by Design-Based Development of Solid Self-Emulsifying Drug Delivery System (SEDDS) as a Potential Carrier for Oral Delivery of Lysozyme

For many years, researchers have been making efforts to find a manufacturing technique, as well as a drug delivery system, that will allow for oral delivery of biopharmaceuticals to their target site of action without impairing their biological activity. Due to the positive in vivo outcomes of this formulation strategy, self-emulsifying drug delivery systems (SEDDSs) have been intensively studied in the last few years as a way of overcoming the different challenges associated with the oral delivery of macromolecules. The purpose of the present study was to examine the possibility of developing solid SEDDSs as potential carriers for the oral delivery of lysozyme (LYS) using the Quality by Design (QbD) concept. LYS was successfully ion paired with anionic surfactant, sodium dodecyl sulphate (SDS), and this complex was incorporated into a previously developed and optimized liquid SEDDS formulation comprising medium-chain triglycerides, polysorbate 80, and PEG 400. The final formulation of a liquid SEDDS carrying the LYS:SDS complex showed satisfactory in vitro characteristics as well as self-emulsifying properties (droplet size: 13.02 nm, PDI: 0.245, and zeta potential: -4.85 mV). The obtained nanoemulsions were robust to dilution in the different media and highly stable after 7 days, with a minor increase in droplet size (13.84 nm) and constant negative zeta potential (-0.49 mV). An optimized liquid SEDDS loaded with the LYS:SDS complex was further solidified into powders by adsorption onto a chosen solid carrier, followed by direct compression into self-emulsifying tablets. Solid SEDDS formulations also exhibited acceptable in vitro characteristics, while LYS preserved its therapeutic activity in all phases of the development process. On the basis of the results gathered, loading the hydrophobic ion pairs of therapeutic proteins and peptides to solid SEDDS may serve as a potential method for delivering biopharmaceuticals orally.

Formulation and In Vivo Evaluation of a Solid Self-Emulsifying Drug Delivery System Using Oily Liquid Tocotrienols as Model Active Substance

Self-emulsifying drug delivery systems (SEDDS) can improve the oral bioavailability of poorly water-soluble drugs. Solid self-emulsifying drug delivery systems (s-SEDDS) offer several advantages including improved drug stability, ease of administration, and production. Most compounds employed in developing s-SEDDS are solid in nature, with a high amount of surfactants added. The aim of this study was to develop an s-SEDDS using a tocotrienol-rich fraction (TRF) as the model liquid active substance via a simple adsorption method. The solid formulation was developed using magnesium aluminosilicate as the carrier with 70% TRF and 30% surfactants (poloxamer and Labrasol^®). The formulation showed good self-emulsification efficiency with stable emulsion formed, excellent powder flowability, and small emulsion droplet size of 210–277 nm. The s-SEDDS with combined surfactants (poloxamer and Labrasol^®) showed a faster absorption rate compared to preparations with only a single surfactant and enhanced oral bioavailability (3.4–3.8 times higher) compared to the non-self-emulsifying oily preparation when administered at a fasted state in rats. In conclusion, an s-SEDDS containing a high amount of TRF was successfully developed. It may serve as a useful alternative to a liquid product with enhanced oral bioavailability and the added advantage of being a solid dosage form.

Effects of Formulation and Manufacturing Process on Drug Release from Solid Self-emulsifying Drug Delivery Systems Prepared by High Shear Mixing

This study sought to investigate the influence of formulation and process factors of the high shear mixing (HSM) on the properties of solid self-emulsifying drug delivery systems (S-SEDDS) containing the model drug carvedilol (CAR). Firstly, liquid SEDDS (L-SEDDS) were prepared by mixing castor oil with different proportions of surfactant (Solutol or Kolliphor RH40) and cosolvent (Transcutol or PEG400). A miscible L-SEDDS with high drug solubility (124.3 mg/g) was selected and gave rise to 10% (m/m) CAR loaded-emulsion with reduced particle size. Then, a factorial experimental design involving five component's concentration and two process factors was used to study the solidification of the selected L-SEDDS by HSM. CAR content, diffractometric profile, and in vitro dissolution were determined. Morphological and flow analyses were also performed. Porous and spherical particles with mean sizes ranging from 160 to 210 µm were obtained. Particle size was not affected by any formulation factor studied. Powder flowability, in turn, was influenced by L-SEDDS and crospovidone concentration. CAR in vitro dissolution from S-SEDDS was significantly increased compared to the drug as supplied and was equal (pH 1.2) or lower (pH 6.8) than that determined for L-SEDDS. Colloidal silicon dioxide decreased drug dissolution, whereas an increase in water-soluble diluent lactose and L-SEDDS concentration increased CAR dissolution. The proper selection of liquid and solid constituents proved to be crucial to developing an S-SEDDS by HSM. Indeed, the results obtained here using experimental design contribute to the production of S-SEDDS using an industrially viable process.

Comparison of Three Different Aqueous Microenvironments for Enhancing Oral Bioavailability of Sildenafil: Solid Self-Nanoemulsifying Drug Delivery System, Amorphous Microspheres and Crystalline Microspheres

Background

The purpose of this study was to screen various drug delivery systems for improving the aqueous solubility and oral bioavailability of sildenafil. Three representative techniques, solid self-nanoemulsifying drug delivery systems (SNEDDS), amorphous microspheres and crystalline microspheres, were compared.

Methods

Both microspheres systems contained sildenafil:Labrasol:PVP at a weight ratio of 1:1:6. The amorphous microspheres were manufactured using ethanol, while crystalline microspheres were generated using distilled water. Liquid SNEDDS was composed of sildenafil:Labrasol:Transcutol HP:Captex 300 in the ratio of 1:70:15:15 (w:w:w:w). The solidification process in SNEDDS was performed using HDK N20 Pharma as a solid carrier.

Results

The amorphous microspheres appeared spherical with significantly decreased particle size compared to the drug powder. The crystalline microspheres exhibited a rough surface with no major particle-size difference compared with sildenafil powder, indicating that the hydrophilic excipients adhered to the sildenafil crystal. Solid SNEDDS presented a smooth surface, assuming that the oily liquid was adsorbed to the porous solid carrier. According to the physicochemical evaluation, the crystalline state maintained in crystalline microspheres, whereas the crystal state changed to amorphous state in other formulations. Amorphous microspheres, crystalline microspheres and solid SNEDDS produced about 79, 55, 82-fold increased solubility, compared to drug powder. Moreover, the prepared formulations provided a higher dissolution rate (%) and plasma concentration than did the drug powder (performance order; solid SNEDDS ≥ amorphous microspheres ≥ crystalline microspheres > drug powder). Among the formulations, solid SNEDDS demonstrated the highest improvement in oral bioavailability (AUC; 1508.78 ± 343.95 h·ng/mL).

Conclusion

Therefore, solid SNEDDS could be recommended as an oral dosage form for enhancing the oral bioavailability of sildenafil.

The importance of the coating material type and amount in the preparation of liquisolid systems based on magnesium aluminometasilicate carrier

Albeit the preparation of liquisolid systems represents an innovative approach to enhance the dissolution of poorly soluble drugs, their broader utilization is still limited mainly due to the problematic conversion of the liquid into freely flowing and readily compressible powder. Accordingly, the presented study aims to determine the optimal carrier/coating material ratio (R value) for formulations based on magnesium aluminometasilicate (NUS2) loaded with polyethylene glycol 400. Four commercially available colloidal silica were used as coating materials in nine different R values (range of 5 - 100). The obtained results suggested that the higher R value leads to the superior properties of powder mixtures, such as better flowability, as well as compacts with higher tensile strength and lower friability. Moreover, it was observed that the type of coating material impacts the properties of liquisolid systems due to the different arrangement of particles in the liquisolid mixture. To confirm the noted dependency of R value and coating material type, the one- and two-way ANOVA, linear regression and principal component analysis (PCA) techniques were performed. In addition, a comparison of results with the properties of loaded NUS2 itself revealed that LSS with sufficient properties may be prepared even without the coating material.

Sublingual indocyanine green films for non-invasive swallowing assessment and inflammation detection through NIR/SWIR optical imaging

Indocyanine green (ICG) is the most commonly used FDA-approved agent for clinical optical imaging, administered through injections only, due to its poor membrane permeability. Although ICG has vast potential for non-invasive non-radioactive imaging in patients, the clinical applications are limited by the invasive administration and short half-life in blood circulation. To expand the clinical value of ICG, non-toxic chitosan-based ICG-loaded films were designed for sublingual administration for near-infrared (NIR) and short-wave infrared (SWIR) optical imaging. Two film formulations were developed with different ICG release rates. Mold-casted self-emulsifying films rapidly released ICG (80% in 4 h) in the form of nanosized droplets, which were mostly swallowed and produced significant contrast of upper digestive tract to enable in vivo swallowing evaluations using NIR/SWIR imaging. Regular films released ICG slowly (80% in 25 h), allowing for steady absorption of ICG to systemic circulation. Inflammation in mouse feet was detected within 30 min after sublingual administration with a 1.43-fold fluorescence increase within 1 h at the inflammation sites, comparable to a 1.76-fold increase through intravenous injection. Administering ICG using sublingual films displayed notable potential for non-invasive diagnosis and monitoring of inflammatory conditions and swallowing disorders, addressing a current need for alternatives to ICG parenteral administration.

17-α Hydroxyprogesterone Nanoemulsifying Preconcentrate-Loaded Vaginal Tablet: A Novel Non-Invasive Approach for the Prevention of Preterm Birth

Preterm birth (PTB) is a major cause of infant mortality in the United States and around the globe. Makena^®—once-a-week intramuscular injection of 17-α Hydroxyprogesterone caproate (17P)—is the only FDA approved treatment for the prevention of PTB. Invasive delivery of 17P requires hospitalization and expert personnel for injection. Vaginal delivery of 17P would be preferable, because of high patient compliance, reduced systemic exposure, fewer side effects, and no need for hospitalization. The objective of the present study was to prepare and evaluate a self-nanoemulsifying vaginal tablet of 17P. A solid self-nanoemulsifying preconcentrate (S-SNEDDS) of 17P and dimethylacetamide (DMA) was developed using medium chain triglycerides, a non- immunogenic surfactant, and co-processed excipient (PVA-F100). The tablet prepared was characterized for emulsification time, particle size, solid state properties, and drug release. The formulation showed >50% inhibition of TNF-α release from LPS-stimulated RAW 264.7 cells. Importantly, there were significant differences in rates of PTB and average time to delivery between control and vaginal 17P-treated groups in LPS-stimulated timed pregnant E15.5 mice. Considering the lacuna of therapeutic approaches in this area, vaginal delivery of 17P for the prevention of preterm birth has significant clinical relevance.