Determination of Required HLB of Capryol 90

Design and Evaluation of Clove Oil-Based Self-Emulsifying Drug Delivery Systems for Improving the Oral Bioavailability of Neratinib Maleate

Neratinib maleate (NM), a tyrosine kinase inhibitor, is used in the treatment of breast cancer. NM is orally administered at a high dose of 290 mg due to its low solubility and poor dissolution rate at pH > 3, as well as gut-wall metabolism limiting its bioavailability. Self-emulsifying drug delivery systems (SEDDSs) of NM were developed in the current study to improve its oral bioavailability. The oily vehicle (clove oil) was selected based on the solubility of NM, while the surfactant and the cosurfactant were selected based on the turbidimetric analysis. Three different sets were screened for surfactant selection in the preparation of SEDDS formulations, the first set containing Cremophor® EL alone as the surfactant, the second set containing a mixture of Cremophor® EL (surfactant) and Caproyl® PGMC (cosurfactant), and the third set containing a mixture of Cremophor® EL (surfactant) and Capmul® MCM C8 (cosurfactant). Propylene glycol was used as the cosolubilizer in the preparation of SEDDSs. A series of studies, including the construction of ternary phase diagrams to determine the zone of emulsification, thermodynamic stability studies (involving dilution studies, freeze-thaw, and heating-cooling studies), turbidimetric analysis, and physicochemical characterization studies were conducted to identify the two most stable combinations of SEDDSs. The two optimized SEDDS formulations, TP16 and TP25, consisted of clove oil (45% w/w) and propylene glycol (5% w/w) in common but differed with respect to the surfactant or surfactant mixture in the formulations. TP16 was prepared using a mixture of Cremophor® EL (surfactant) and Caproyl® PGMC (cosurfactant) in a 4:1 ratio (50% w/w), while TP25 contained only Cremophor® EL (50% w/w). The mean globule sizes were 239.8 ± 77.8 nm and 204.8 ± 2.4 nm for TP16 and TP25, respectively, with an emulsification time of <12 s for both formulations. In vitro drug dissolution studies performed at different pH conditions (3.0, 4.5, 6.8) have confirmed the increase in solubility and dissolution rate of the drug by TP16 and TP25 at all pH conditions compared to plain NM. An oral pharmacokinetic study in female Wistar rats showed that the relative bioavailability (Frel) values of TP16 and TP25 over the plain NM were 2.18 (p < 0.05) and 2.24 (p < 0.01), respectively.

Enhanced circulation longevity and pharmacodynamics of metformin from surface-modified nanostructured lipid carriers based on solidified reverse micellar solutions

Metformin hydrochloride (MTH) has been associated with poor/incomplete absorption (50–60%), low bioavailability, short half-life (0.4–0.5 h), high dosage and dose-related side effects. To overcome these barriers and improve oral bioavailability and efficacy of MTH, surface-modified nanostructured lipid carriers (NLCs) were developed. Lipid matrices composed of rational blends of beeswax and Phospholipon® 90H (as solid lipids) and Capryol-PGE 860 (as liquid lipid) were prepared by fusion, and the resultant lipid matrices were PEGylated to give 10, 20 and 40% PEGylated lipid matrices. MTH-loaded non-PEGylated and PEGylated NLCs were prepared via high-shear hot homogenization and characterized regarding particle properties and physicochemical performance. The encapsulation efficiencies (EE%) and loading capacities (LC) of the MTH-loaded NLCs were determined while the in vitro drug release was evaluated in phosphate buffered saline (PBS, pH 7.4). Antidiabetic and pharmacokinetics properties of the NLCs were ascertained in an alloxan-induced diabetic rats model after oral administration. The MTH-loaded NLCs were nanomeric (particle size: 184.8–882.50 nm) with low polydispersity index (0.368–0.687) and zeta potential (26.5–34.2 mV), irregular shape, amorphous nature with reduced crystallinity. The EE% and LC were >90 % and 16%, respectively. The formulations showed >65 % release over 12 h in a greater sustained manner than marketed MTH formulation (Glucophage®) as well as enhanced pharmacokinetics properties and sustained blood glucose lowering effect, even at reduced doses with PEGylated NLCs than Glucophage®. Thus, PEGylated NLC is a promising approach for improved delivery and oral bioavailability of MTH thus encouraging further development of the formulation.

Design and Optimization of Pioglitazone Hydrochloride Self-Nanoemulsifying Drug Delivery System (SNEDDS) Incorporated into an Orally Disintegrating Tablet

Pioglitazone Hydrochloride (PGZ) suffers from poor aqueous solubility. The aim of this research was to design orally disintegrating tablets with self-nanoemulsifying properties (T-SNEDDS) to improve the Pioglitazone solubility and dissolution rate. Three liquid self-nanoemulsifying systems (L-SNEDDS) were formulated and evaluated for transmittance percentage, emulsification time, particle size, Poly dispersity index (PDI), percentage of content, solubility and stability. The optimum L-SNEDDS formula was converted to a solidified self-nanoemulsifying drug delivery system (S-SNEDDS) by adsorption on Syloid (SYL). Powder characterization tests, such as flowability tests, differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM), were performed for the selected S-SNEDDS formulation. Orally disintegrating tablets (ODT) were formulated by blending S-SNEDDS with tableting excipients. The ODT tablet batch composed of Prosolv was selected for tablet quality control tests, such as hardness, friability, disintegration time, content uniformity, weight variation, in vitro release, in vivo studies and accelerated stability studies. ODT tablets showed accepted mechanical properties and rapid disintegration time (<30 s). No drug degradation was observed at 3 months into the accelerated stability study. The optimized L-SNEDDS, S-SNEDDS and ODT (T-SNEDDS), showed significant enhancement of PGZ in vitro dissolution profiles compared to the pure drug (p > 0.05). In vivo pharmacokinetic and pharmacodynamic evaluation of ODTs showed better behavior compared to the raw drug suspension and the commercial tablet (p > 0.05). Orally disintegrating tablets revealed a promising potential to improve Pioglitazone poor aqueous solubility, dissolution profile and bioavailability.

Enhanced Oral Bioavailability and Improved Biological Activities of a Quercetin/Resveratrol Combination Using a Liquid Self-Microemulsifying Drug Delivery System

Both quercetin and resveratrol are promising plant-derived compounds with various well-described biological activities; however, they are categorized as having low aqueous solubility and labile natural compounds. The purpose of the present study was to propose a drug delivery system to enhance the oral bioavailability of combined quercetin and resveratrol. The suitable self-microemulsifying formulation containing quercetin together with resveratrol comprised 100 mg Capryol 90, 700 mg Cremophor EL, 200 mg Labrasol, 20 mg quercetin, and 20 mg resveratrol, which gave a particle size of 16.91 ± 0.08 nm and was stable under both intermediate and accelerated storage conditions for 12 months. The percentages of release for quercetin and resveratrol in the self-microemulsifying formulation were 75.88 ± 1.44 and 86.32 ± 2.32%, respectively, at 30 min. In rats, an in vivo pharmacokinetics study revealed that the area under the curve of the self-microemulsifying formulation containing quercetin and resveratrol increased approximately ninefold for quercetin and threefold for resveratrol compared with the unformulated compounds. Moreover, the self-microemulsifying formulation containing quercetin and resveratrol slightly enhanced the in vitro antioxidant and cytotoxic effects on AGS, Caco-2, and HT-29 cells. These findings demonstrate that the self-microemulsifying formulation containing quercetin and resveratrol could successfully enhance the oral bioavailability of the combination of quercetin and resveratrol without interfering with their biological activities. These results provide valuable information for more in-depth research into the utilization of combined quercetin and resveratrol.

Solid self-nanoemulsifying drug delivery system filled in enteric coated hard gelatin capsules for enhancing solubility and stability of omeprazole hydrochloride

Omeprazole has poor water solubility, low stability in acidic solutions, and is subject to first pass metabolism resulting in low bioavailability. The objective was to enhance the dissolution and stability by preparing a solid-self nanoemulsifying drug delivery system (SNEDDS) and filling it in enteric coated HGCs. Drug solubility in many oils, surfactants, and cosurfactants was studied. Different SNEDDS were prepared and ternary phase diagrams were constructed. The optimum SNEDDS was evaluated. It was converted into solid by adsorption onto Neusilin^® US2, and evaluated. Emulsions formed using Capryol 90, Cremophor RH 40, and ethanol formed spontaneously and were clear. Droplet size was 19.11 ± 3.11 nm, PDI was 0.18 ± 0.05, and zeta potential was -3.9 ± 1.56 mV. Non-medicated SNEDDS was thermodynamically stable. Cloud point was 88 ± 2 °C. Encapsulation efficiency and drug loading of solid-SNEDDS were 98.56 ± 0.44 and 1.29 ± 0.01%, respectively. Flow properties were much enhanced. Crystalline drug was adsorbed/precipitated onto Neusilin^® US2 in amorphous form. Dissolution rate was enhanced as compared to commercial products and unprocessed drug. The drug was unstable at the accelerated stability conditions. Accordingly, the traditional stability study at 25 °C should be conducted. In conclusion, the solid-SNEDDS filled in enteric coated HGCs enhanced the dissolution rate and stability in acidic pH.

Nanocarriers enhance the transdermal bioavailability of resveratrol: In-vitro and in-vivo study

The aim of this study was to develop and assess the potential of nanostructured emulsion carriers for resveratrol topical application. Different compositions of resveratrol-loaded nanostructured emulsions were prepared using different types and amounts of surfactants and oily phases (isopropyl myristate and caproyl 90). The produced nanostructured emulsions were within the nanosized range 23.4-422.2nm with low viscosity range 2.15-17.53cps. The transdermal amount and deposition amount in the skin after 24 applications of resveratrol-loaded nanostructured emulsion were significantly increased about 896.2-fold and 10.2-fold respectively, when compared to the drug-saturated solution-treated group. Nanostructured emulsion containing IPM and low amounts of mixed surfactant of Tween80/Span 20 showed highest permeation capacity. In vivo study showed that the plasma concentration of resveratrol could be maintained at high levels for a long time after topical application of drug-loaded nanostructured emulsion. The histological examination demonstrated that the free drug- and drug-loaded nanostructured emulsion demonstrated considerably less irritation than the standard irritation group (0.8% paraformaldehyde-treated). The residual contents of resveratrol in the tested formulations after 3 months of storage at 25°C and 40°C were more than 99.97±3.90%. The results of present work confirm the high potential of nanostructured emulsion as carriers for drug topical application.

Simultaneous analysis of skin penetration of surfactant and active drug from fluorosurfactant-based microemulsions

The purpose of this study was to investigate the penetrated amount of the incorporated model drug diclofenac-sodium and of a fluorosurfactant as specific vehicle constituent of topically applied microemulsions at the same time. To this end, the penetration depth of each compound was elucidated through tape stripping studies by the simultaneous quantification of diclofenac-sodium and the fluorosurfactant from the same sample. A new approach was made by using the very sensitive and specific (19)F NMR (nuclear magnetic resonance) for quantification of the fluorinated vehicle component. The tape stripping experiments with the microemulsions showed an almost similar penetration velocity of diclofenac-sodium and fluorosurfactant, suggesting that the surfactant within the microemulsion-structure intensified the stratum corneum uptake of the incorporated active constituent. Moreover, ATR-FTIR studies on porcine ear skin revealed significant shifts of the CH₂ stretching absorbances, which are associated with an enhanced disorder of the SC lipids resulting in a decreased skin barrier function, after application of the microemulsions. However, the application of pure fluorosurfactant did not cause any shifts in the CH₂ stretching absorbances. It can be thereby concluded that the prepared microemulsions exerted specific effects on skin integrity resulting in a "push" of diclofenac-sodium penetration.