• Journal of Pharmaceutical Investigation
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• v.29 no.2
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• pp.99-103
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• 1999

Self-Emulsifying System(SES), an isotropic mixture of oil and surfactant which forms oil-in-water emulsion, is expected to improve in vitro drug dissolution and enhance in vivo drug absorption. A poorly water soluble drug, ibu-profen(IBP) was incorporated into the SES to improve absorption, and enhance bioavailability of drug. Medium chain triglyceride, glyceryl tricaprylate(GTC) as an oil, and Tween 85 as a surfactant were used to formulate SES. To characterize SESs with various concentrations of Tween 85, the phase separation and solubility of IBP-SEDDS containing IBP as a function of Tween 85 concentration were conducted, and the particle size was measured using photon correlation spectroscopic method. The SES with optimal concentration of Tween 85(35%(w/w)) was selected based on its high drug loading, small particle size and low surfactant concentration. After an oral administration of IBP-SEDDS and IBP suspension in methyl cellulose equivalent to 40.0 mg/kg to rats, the pharmacokinetic parameters were compared. The $C_{max}(163.17\;vs\;88.82\;{\mu}g/ml)$, $AUC(12897.01\;vs\;8751.13\;{\mu}g\;min/ml)$ and Bioavailability(86.44 vs 58.65%) significantly increased but $T_max(10\;vs\;20\;min)$ was significantly advanced. The current SEDDS containing IBP provide an alternative to improve an oral bio-availability of IBP.

• Journal of Pharmaceutical Investigation
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• v.37 no.5
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• pp.291-295
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• 2007

Prostaglandin $E_1\;(PGE_1)$ was formulated as two self-microemulsifying drug delivery systems (SMEDDS) composed of Cremophor $EL^{(R)}$ or Cremophor $ELP^{(R)}$ as a surfactant, ethanol as a cosurfactant and Labrafac $CC^{(R)}$ as an oil to develop liquid preparation for the treatment of erectile dysfunction. In pseudo-ternary phase diagram, viscous gel area and microemulsion area were defined. In the measurement of viscosity, the viscosity of two formulations increased gradually upon the addition of water and it decreased from the water contents over 40%. With excessive water, the present systems formed a microemulsion spontaneously. From these results, rte could expect that the present liquid $PGE_1$ SMEDDS formulations might stay within the urethra in the viscous state when contacting the moisture of the urethra and can be easily eliminated by urination. In long-term stability study, we could select one formulation more stable at the shelf storage condition of $4^{\circ}C$.

• Journal of Pharmaceutical Investigation
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• v.40 no.6
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• pp.339-345
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• 2010

Fenofibrate has been used for many years to lower cholesterol levels and its pharmacokinetic profile is well understood. However, due to its low solubility in water, it has low bioavailability after oral administration. In order to improve the dissolution rate, fenofibrate was formulated into a self-microemulsifying drug delivery systems (SMEDDS). We used pseudo-ternary phase diagrams to evaluate the area of microemulsification, and an in vitro dissolution test was used to investigate the dissolution rate of fenofibrate. The optimized formulation for in vitro dissolution assessment consisted of Lauroglycol FCC (60%), Solutol HS 15 (27%), and Transcutol-P (13%). The mean droplet size of the oil phase in the microemulsion formed from the SMEDDS was about 130 nm. The dissolution rate of fenofibrate from SMEDDS was significantly higher than that of the reference tablet. Our studies suggested that the fenofibrate containing SMEDDS composition can effectively increase the solubility and oral bioavailability of poorly water-soluble drugs.

• Journal of Pharmaceutical Investigation
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• v.41 no.4
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• pp.249-253
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• 2011

To develop a sildenafil lactate-loaded solid self-emulsifying drug delivery system (SEDDS) with a fast onset of action and immediate action of erection, sildenafil lactate (0.3 g), which was prepared using a spray dryer, was dissolved in 4.7 g of the mixture of glyceryl monooleate/Transcutol/ Tween 20 (3/0.5/1, g). Its emulsion droplet size and pharmacokinetics in rabbits were evaluated compared with sildenafil citrate-loaded commercial tablet. The sildenafil lactateloaded SEDDS showed an emulsion droplet size of about 300 nm. In pharmacokinetics study, it gave significantly faster Tmax than did the commercial tablet. Thus, the sildenafil lactate-loaded SEDDS at the one-third drug dose compared to sildenafil citrate-loaded conventional tablet might induce a fast onset of action and immediate erection without enhanced bioavailability compared with the sildenafil citrate-loaded commercial tablet.

• Journal of Pharmaceutical Investigation
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• v.32 no.4
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• pp.267-275
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• 2002

A self-microemulsifying drug delivery system (SMEDDS) was developed to increase the dissolution rate, solubility, and ultimately bioavailability of a poorly water soluble drug, lovastatin. SMEDDS was thε mixtures of oils, surfactants, and cosurfactants, which emulsify under conditions of gentle agitation, similar to those which would be encountered in the gastro-intestinal (GI) tract. Various types of self-emulsifying formulations were prepared using four types of oil (Capryol 90, Lauroglycol 90, Labrafil M 1944 CS and Labrafil M 2125), two surfactants (Cremophor EL and Tween 80), and three cosurfactants (Carbitol, PEG 400 and propylene glycol). Thε efficiency of emulsification was studied using a laser diffraction size analyzer to determine particle size distributions of the resultant emulsions. Optimized formulations selected for bioavailability assessment were Carpryol 90 (40%), Cremophor EL (30%) and Carbitol (30%). SMEDDS containing lovastatin (20 mg and 5 mg) were compared to a conventional lovastatin tablet $(Mevacor^{\circledR},\;20\;mg/tab)$ by the oral administration as prefilled hard gelatin capsules to fasted beagle dogs for in vivo study. The arεa under the serum concentration-time curve from time zero to the last measured time in serum, $AUC_{0{\rightarrow}24h}$, was significantly greater in SMEDDS, suggesting that bioavailability increase 130% and 192% by the SMEDDS, respectively. The self-emulsifying formulations of lovastatin afforded the improvement in absolute oral bioavailability relative to previous data of lovastatin tablet formulation. These data indicate the utility of dispersed self-emulsifying formulations for the oral delivery of lovastatin and potentially other poorly absorbed drugs.

• Journal of Powder Materials
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• v.30 no.4
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• pp.305-309
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• 2023

This study aims to prepare a colloidal silica-containing powder to enhance the solubility and dissolution rate of rivaroxaban using a self-nanoemulsifying drug delivery system (SNEDDS). We investigate the impact of colloidal silica on a nanoemulsion system for preparing powdered SNEDDS. The liquid SNEDDS comprises 30/20/50 (w/w/w) Peceol/Cremophor RH40/Tween 80, which results in the formation of the smallest droplets. Three powdered SNEDDS formulations are prepared by suspending the liquid SNEDDS formulation using colloidal silica and spray drying. The powdered SNEDDS prepared with liquid SNEDDS and colloidal silica at a ratio of 1/0.5 (w/w) exhibits the highest water solubility (0.94 ± 0.62 vs. 26.70 ± 1.81 ㎍/mL) and dissolution rate (38.4 ± 3.6 vs. 85.5 ± 3.4%, 45 min) when compared to the drug alone. Morphologically, the liquid SNEDDS is adsorbed onto colloidal silica and forms smaller particles. In conclusion, an SNEDDS containing rivaroxaban, prepared using colloidal silica, facilitates the creation of a nanoemulsion and enhances the water solubility of rivaroxaban. Accordingly, this technology holds significant potential for commercialization.

• Journal of Pharmaceutical Investigation
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• v.39 no.2
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• pp.111-115
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• 2009

The pharmacokinetics of cyclosporin A (CsA) after single and multiple oral dosing of new CsA self-micro-emulsifying drug delivery system (SMEDDS) in dogs were estimated. A single dose study was performed following a two-way crossover design against six dogs with reference SMEDDS. For a multiple dose study, three dogs were allocated for each drug, and 100 mg of drug was administered daily for 6 days. Whole blood concentration of CsA was analyzed by radio-immunoassay. Both drug showed identical blood concentration profiles in both studies, and no statistical difference was detected in pharmacokinetic parameters. The relative bioavailabilities of test SMEDDS were 91.4% and 89.1%, respectively, in the single dose study and the last day of multiple dose study. Especially, multiple dose study proved the good relationship between C-0/C-2 and AUC for reference SMEDDS, which is an indispensable part of therapeutic drug monitoring. These results suggest newly formulated CsA SMEDDS possibly shows identical pharmacokinetics and pharmacodynamic behaviors in clinical trials.

• Biomolecules & Therapeutics
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• v.8 no.3
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• pp.269-275
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• 2000

Silibinin(silybin) is the active component of silymarin from Silybum marianum and has hepato-protective effect. It is water-insoluble and has low bioavailability. To improve its bioavailability, self-micro-emulsifying drug delivery system (SMEDDS) has been developed by Hanmi Pharmaceutical Company (Silyma $n^{R}$ 140 soft capsule). In this study, the pharmacokinetic profiles of Silyma $n^{R}$ were examined and compared it with a reference preparation, L Caps140 of B Pharmaceutical Company. This study was approved by Yonsei University Severance Hospital IRB(approval No. CR0004) and followed the bioequivalence test guideline of Korean FDA. Eighteen healthy adult volunteers were allocated based on 2$\times$2 Latin square cross-over design. They were given 2 capsules (each contains silymarin 140 mg (60 mg as silibinin)) of either drug at each period and crossed over after a week of drug-free washout period. Blood concentration of silibinin was measured by HPLC. The $C_{max}$ and AUC of the Silyma $n^{R}$ were 1542.0 $\pm$ 402.7 ng/ml and 3323.3 $\pm$ 824.7 ng.h/ml, respectively, and were significantly higher than those of reference preparation. The Tmax was 0.8 $\pm$ 0.3 h and significantly shorter than reference preparation. The $K_{e}$ and $T_{1}$2/ of both drugs were comparable. Percent differences in means against reference preparation were +88.3% for AUC, +222.6% for $C_{max}$, and -61.1% for $T_{max}$./.>././.>./.