Chi-Te Huang

In vitro permeation and in vivo whitening effect of topical hesperetin microemulsion delivery system.

Hesperetin is one of the flavonoids and possess anti-inflammatory, UV-protecting and antioxidant effects. Permeation issues for topical delivery systems of such effects are occasionally problematic, and in view of the fact that microemulsions are potential carriers for transdermal delivery system, the objective of this study was to design an optimal microemulsion formulation by in vitro permeation study for hesperetin topical dosage form and determine its topical photoprotective effect and skin irritation by in vivo study. The hesperetin-loaded microemulsion showed an enhanced in vitro permeation compared to the aqueous and isopropyl myristate (IPM) suspension dosage form of hesperetin. In comparison, the effect of co-surfactant on the drug permeation capacity, propylene glycol showed highest permeation rate, followed by ethanol, glycerol and polyethylene glycol (PEG 400). Sunscreen agent padimate O, as a transdermal enhancer could increase the permeation rate of hesperetin. In case of in vivo study, the hesperetin-loaded microemulsion showed significant topical whitening effect and diminished skin irritation when compared with the non-treatment group, indicating that the hesperetin microemulsion could be used as an effective whitening agent.

The Effect of Component of Microemulsions on Transdermal Delivery of Buspirone Hydrochloride

The aim of this study was to evaluate the influence of components such as type, level, and hydrophilic-lipophilic balance (HLB) value of surfactant, type and amount of cosurfactant, and drug concentration on the permeability of buspirone hydrochloride microemulsions through rat skin. The cumulative amount at 24 h ranged from 502.2 ± 57.8 to 1754.3 ± 616.6 μg/cm(2), flux ranged from 23.03 ± 1.84 to 83.36 ± 25.08 μg/(cm(2)/h), and lag time ranged from 3.0 to 4.7 h, indicating that the permeation parameters of buspirone from microemulsions were markedly influenced by the composition of microemulsions. In comparison with the effect of composition of microemulsions on the buspirone permeation capacity, it was found that microemulsions containing surfactant with HLB value of 11.16 possessed higher flux. The viscosity of microemulsions increased, flux decreased, and lag time was prolonged when amount of surfactant in microemulsions increased. The various cosurfactants can also influence the microemulsion formation and drug permeability. The microemulsion with ethanol as cosurfactant had higher permeation rate. However, the buspirone microemulsion with higher flux can provide the therapeutic minimum effective concentration, at workable administrated area about 3.3-5.8 cm(2), demonstrating microemulsions could be a promising drug carrier for transdermal delivery systems.

Anti-oxidant activity and attenuation of bladder hyperactivity by the flavonoid compound kaempferol

To evaluate the anti‐oxidant activity of the flavonoid compound, kaempferol, and to examine its role in the suppression of oxidative stress and attenuation of bladder hyperactivity in a rat model of bladder injury.

Effect of microemulsions on transdermal delivery of citalopram: optimization studies using mixture design and response surface methodology

The aim of this study was to evaluate the potential of microemulsions as a drug vehicle for transdermal delivery of citalopram. A computerized statistical technique of response surface methodology with mixture design was used to investigate and optimize the influence of the formulation compositions including a mixture of Brij 30/Brij 35 surfactants (at a ratio of 4:1, 20%–30%), isopropyl alcohol (20%–30%), and distilled water (40%–50%) on the properties of the drug-loaded microemulsions, including permeation rate (flux) and lag time. When microemulsions were used as a vehicle, the drug permeation rate increased significantly and the lag time shortened significantly when compared with the aqueous control of 40% isopropyl alcohol solution containing 3% citalopram, demonstrating that microemulsions are a promising vehicle for transdermal application. With regard to the pharmacokinetic parameters of citalopram, the flux required for the transdermal delivery system was about 1280 μg per hour. The microemulsions loaded with citalopram 3% and 10% showed respective flux rates of 179.6 μg/cm2 and 513.8 μg/cm2 per hour, indicating that the study formulation could provide effective therapeutic concentrations over a practical application area. The animal study showed that the optimized formulation (F15) containing 3% citalopram with an application area of 3.46 cm2 is able to reach a minimum effective therapeutic concentration with no erythematous reaction.

Formulation optimization of estradiol microemulsion using response surface methodology.

The aim of the current study was to find an optimal estradiol-loaded microemulsion with higher permeation rate and shortened lag time (LT) for transdermal application by using a response surface methodology (RSM) and constrained mixture design. Isopropyl myristate (X1 ), distilled water (X2 ), and ethanol (X3 ) were selected as independent variables, whereas the viscosity of microemulsion and permeation parameters including the cumulative amount at 24 h (Q24h ) and LT of estradiol-loaded microemulsion through skin were set as dependent variables. The result showed that the three independent variables had a remarkable effect (p < 0.05) on the dependent variables. Moreover, the predicted and observed values of these three dependent variables of the optimal microemulsion formulations, which were produced by the RSM optimization technique, were close, demonstrating that RSM was a useful technique for optimizing pharmaceutical formulations. However, the experimental estradiol-loaded microemulsion with higher permeation rate was expected to provide effective therapeutic concentration in a workable administration area.

Isotretinoin oil-based capsule formulation optimization.

The purpose of this study was to develop and optimize an isotretinoin oil-based capsule with specific dissolution pattern. A three-factor-constrained mixture design was used to prepare the systemic model formulations. The independent factors were the components of oil-based capsule including beeswax (X 1), hydrogenated coconut oil (X 2), and soybean oil (X 3). The drug release percentages at 10, 30, 60, and 90 min were selected as responses. The effect of formulation factors including that on responses was inspected by using response surface methodology (RSM). Multiple-response optimization was performed to search for the appropriate formulation with specific release pattern. It was found that the interaction effect of these formulation factors (X 1 X 2, X 1 X 3, and X 2 X 3) showed more potential influence than that of the main factors (X 1, X 2, and X 3). An optimal predicted formulation with Y 10 min, Y 30 min, Y 60 min, and Y 90 min release values of 12.3%, 36.7%, 73.6%, and 92.7% at X 1, X 2, and X 3 of 5.75, 15.37, and 78.88, respectively, was developed. The new formulation was prepared and performed by the dissolution test. The similarity factor f 2 was 54.8, indicating that the dissolution pattern of the new optimized formulation showed equivalence to the predicted profile.

The transport effect of submicron emulsions on 5-flurouracil topical application

Water-in-oil submicron emulsions were used as carrier for the topical delivery of 5-fluorouracil (5FU). The effect of components such as level and hydrophilic–lipophilic balance (HLB) value of surfactant, type of cosurfactant, and drug concentration on the delivery capability of drug in the receptor fluid and in the various skin layers (stratum corneum, epidermis and dermis) were evaluated. The result showed the submicron emulsion could increase the transdermal and deposition of 5FU compared with the aqueous control. Submicron emulsion with surfactant at HLB of 6.0 had higher deposition amount of drug in epidermis layer. The deposition amount of drug in the skin layers increased with increased amounts of surfactant and drug loading of submicron emulsion. However, the 0.2% 5FU-load submicron emulsion showed a comparable deposition effect in various skin layers with the commercial product (5%, Efudix®), which indicated that the submicron emulsions could be a promising drug vehicle for topical application.

Formulation optimization of transdermal meloxicam potassium-loaded mesomorphic phases containing ethanol, oleic acid and mixture surfactant using the statistical experimental design methodology

Response surface methodology (RSM) was used to develop and optimize the mesomorphic phase formulation for a meloxicam transdermal dosage form. A mixture design was applied to prepare formulations which consisted of three independent variables including oleic acid (X1), distilled water (X2) and ethanol (X3). The flux and lag time (LT) were selected as dependent variables. The result showed that using mesomorphic phases as vehicles can significantly increase flux and shorten LT of drug. The analysis of variance showed that the permeation parameters of meloxicam from formulations were significantly influenced by the independent variables and their interactions. The X3 (ethanol) had the greatest potential influence on the flux and LT, followed by X1 and X2. A new formulation was prepared according to the independent levels provided by RSM. The observed responses were in close agreement with the predicted values, demonstrating that RSM could be successfully used to optimize mesomorphic phase formulations.