Transdermal Delivery of Ketoprofen: The Influence of Drug–Dioleylphosphatidylcholine Interactions

Ethosome-Derived Invasomes as a Potential Transdermal Delivery System for Vardenafil Hydrochloride: Development, Optimization and Application of Physiologically Based Pharmacokinetic Modeling in Adults and Geriatrics

Aim

The aim of the current work was to develop vardenafil hydrochloride (VRD)-loaded ethosome-derived invasomes as a possible transdermal system which could be used for patients suffering from pulmonary arterial hypertension.

Methods

VRD-loaded ethosomes were developed at three concentrations of phosphatidylcholine (5, 10 and 15 mg/mL) and three percentages of ethanol (20%, 30% and 40%, v/v). The best achieved VRD-loaded ethosomes (ETH9) were optimized to invasomes via incorporation of terpenes (limonene, cineole and a 1:1 mixture) at three concentrations (0.5%, 1% and 2%, v/v). All systems were evaluated for vesicle size, zeta potential, drug entrapment efficiency (EE%), cumulative drug permeated percentages after 0.5hrs (Q_0.5h) and 12hrs (Q_12h) and steady-state flux (J_ss). The optimized system (ETH9-INV8) was further characterized for morphology, histopathology and confocal laser scanning microscopy (CLSM). Physiologically based pharmacokinetic (PBPK) modeling was employed to estimate VRD pharmacokinetic parameters from the optimized transdermal system and an oral aqueous drug dispersion, in adults and geriatrics.

Results

The optimized invasomal system (ETH9-INV8) was characterized with spherical vesicles (159.9 nm) possessing negative zeta potential (-20.3 mV), promising EE% (81.3%), low Q_0.5h (25.4%), high Q_12h (85.3%) and the largest steady-state flux (6.4 µg.cm^-2h^-1). Following a leave-on period of 12hrs in rats, it showed minor histopathologic changes. CLSM studies proved its ability to deeply permeate rat skin. Lower C_max values, delayed T_max estimates and greater AUC_0-24h folds in adults and geriatrics (≈ 2.18 and 1.69, respectively) were estimated following the transdermal application of ETH9-INV8 system.

Conclusion

ETH9-INV8 is a promising transdermal system for VRD.

Ketoprofen Microemulsion for Improved Skin Delivery and In Vivo Anti-inflammatory Effect

We have designed a microemulsion (ME) containing Ketoprofen (KET) for anti-inflammatory effect evaluated using the rat paw edema model. The ME was prepared by adding propylene glycol (PG) loaded with 1% KET/water (3:1, w/w), to a mixture of sorbitan monooleate and polysorbate 80 (47.0%) at 3:1 (w/w) and canola oil (38.0%). The physicochemical characterization of KET-loaded ME involved particle size and zeta potential determination, entrapment efficiency, calorimetric analysis, and in vitro drug release. The in vivo anti-inflammatory study employed male Wistar rats. Measurement of the foot volume was performed using a caliper immediately before and 2, 4, and 6 h after injection of Aerosil. KET-loaded ME showed particle size around 20 nm, with zeta potential at -16 mV and entrapment efficiency at 70%. Moreover, KET was converted to the amorphous state when loaded in the formulation and it was shown that the drug was slowly released from the ME. Finally, the in vivo biological activity was similar to that of the commercial gel, but ME better controlled edema at 4 h. These results demonstrated that the ME formulation is an alternative strategy for improving KET skin permeation for anti-inflammatory effect. Furthermore, our findings are promising considering that the developed ME was loaded with only 1% KET, and the formulation was able to keep a similar release profile and in vivo effect compared to the commercial gel with 2.5% KET. Therefore, the KET-loaded developed herein ME is likely to have a decreased side effect compared with that of the commercial gel, but both presented the same efficacy.

Effect of phonophoresis on skin permeation of commercial anti-inflammatory gels: sodium diclofenac and ketoprofen

This study evaluated the use of ultrasound in combination with the commercial anti-inflammatory drugs ketoprofen and sodium diclofenac, according to the parameters used in physiotherapy. Ketoprofen and sodium diclofenac were used in the Franz diffusion cell model adapted to an ultrasound transducer in three conditions: no ultrasound, one application of ultrasound and two applications of ultrasound. High-performance liquid chromatography was used to quantify the total amount of drug permeating skin per unit area, as well as flux and latency. The results showed that for ketoprofen, the amount of drug permeating skin and flux increased with two ultrasound applications. Permeation of sodium diclofenac decreased in the presence of ultrasound. Ultrasound parameters and drug properties must be considered in the use of phonophoresis.

Influence of critical parameters of nanosuspension formulation on the permeability of a poorly soluble drug through the skin--a case study

In transdermal drug delivery systems, it is always a challenge to achieve stable and prolonged high permeation rates across the skin since the concentrations of the drug dissolved in the matrix have to be high in order to maintain zero order release kinetics. Several attempts have been reported to improve the permeability of poorly soluble drug compounds using supersaturated systems. However, due to thermodynamic challenges, there was a high tendency for the drug to nucleate immediately after formulating or even during storage. The present study focuses on the efficiency of nanoparticles and influence of different concentrations of solubilizer such as vitamin E TPGS (D-a-tocopheryl polyethylene glycol 1000 succinate) to improve the permeation rate through the skin. Effects of several formulation factors were studied on the nanosuspension systems using ibuprofen as a model drug. The overall permeation enhancement process through the skin was influenced mostly by the solubilizer and also by the size of nanoparticles. The gel formulation developed with vitamin E TPGS + HPMC nanosuspension, consequently represent a promising approach aiming to improve the permeability performance of a poorly water soluble drug candidate.

Celecoxib determination in different layers of skin by a newly developed and validated HPLC-UV method

A simple, rapid and sensitive analytical procedure for the measurement of celecoxib (CXB) levels in skin samples after in vitro penetration studies was developed and validated. In vitro permeability studies in porcine skin were performed for quantification of CXB at different layers of skin, the stratum corneum (SC) and epidermis plus dermis (EP + D) as well as in the acceptor solution (AS) to assess CXB permeation through skin. CXB was quantified by HPLC using a C18 column and UV detection at 251 nm. The mobile phase was methanol-water 72:28 (v/v) and the flow-rate was 0.8 mL/min. The CXB retention time was 5 min. The assay was linear for CBX in the concentration range of 0.1-3.0 μg/mL in the AS (drug permeated through skin) and 5.0-50.0 μg/mL for drug retained in SC and [EP + D] in vitro. The linear correlation coefficients for the different calibration curves were equal or greater than 0.99. Intra- and inter-assay variabilities were below 8.0%. Extraction of CXB from skin samples showed recoveries higher than 95.0% after 15 min of ultrasonic sound and centrifugation at 2500 rpm for 3 min. The method was considered appropriate for the assay of CXB in skin samples, after in vitro cutaneous penetration studies.