The Release of Perillyl Alcohol from the Different Kind of Vehicles.

BACKGROUND: Skin cancers are the most common malignancy in humans, and the number of cases has increased dramatically in the past few decades. Therefore, it is very important to carry out studies concerning new and safer anticancer natural agents (e.g. perillyl alcohol) and modern drug delivery systems, such as nanoformulations, which increase their bioavailability. OBJECTIVES: The aim of this work was to obtain different kinds of topical vehicles formulation and compare their efficiency in the release of perillyl alcohol. The release kinetics was determined by using certain selected mathematical models. METHOD: Formulations of a hydrogel, O/W nanoemulsion, O/W macroemulsion and nanostructured lipid carrier were developed as carriers for perillyl alcohol - one of the promising anticancer natural agents. The release study of the active agents was carried out using the Spectra/Por Standard Regenerated Cellulose membrane, at temperature T=320C. The concentration of active agents in the receptor solution was analyzed by high performance liquid chromatography. The release kinetics was determined by using selected mathematical models. RESULTS: The results of our release studies have shown that the highest and comparable amount of perillyl alcohol was released from hydrogel (35.72 ± 0.21%), NLC (35.54 ± 1.48%) and nanoemulsion (34.87 ± 4.49%). The release was found to follow Fickian diffusion in the case of hydrogel and macroemulsion, while an anomalous mechanism was observed in the case of nanoformulations. Nevertheless, the obtained nanoformulations, as well as a conventional hydrogel, may be considered potential vehicles in topical delivery of perillyl alcohol.

Study of O/W micro- and nano-emulsions based on propylene glycol diester as a vehicle for geranic acid.

Nano- and microemulsions containing as the oil phase caprylic/capric propylene glycol diesters (Crodamol PC) were investigated as potential vehicle for controlled release of geranic acid. The influence of emulsifiers and co-surfactants on stability of the emulsions was investigated. Different kind of polysorbates (ethoxylated esters of sorbitan and fatty acids) were applied as the emulsifiers. The short-chain alcohols (ethanol, 1-propanol, 1-butanol) were used as co-surfactants. The emulsions were prepared at ambient temperature (25°C), by the phase inversion composition method (PIC). The stable O/W high dispersed emulsion systems based on Crodamol PC, of mean droplets size less than 200 nm, were prepared. Microemulsions stabilized by the mixture of Polisorbat 80 and 1-butanol were characterized by the largest degree of dispersion (137 nm) and the lowest PDI value (0.094), at surfactant/co-surfactant: oil weight ratio 90:10. The stable nano-emulsion (mean droplet size of 33 nm) was obtained for surfactant: oil (S:O) weight ratio 90:10, without co-surfactant addition. This nano-emulsion was chosen to release studies. The obtained results showed that the prepared stable nano-emulsion can be used as a carrier for controlled release of geranic acid. The active substance release from the nano-emulsion and the oil solution, after 24 hours was 22%.