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Background/aim Cigarette smoke (CS) is a major environmental health threat. The oxidative stress induced by CS on keratinocytes and the possible protective effect of nicotine, its receptor inhibitors, and Pinus halepensis bark extract in relation to known antioxidants were investigated. Materials and methods Primary mouse keratinocytes were exposed to cigarette smoke in the presence and absence of Pinus halepensis bark extract (1 μg/ml), rutin (50 μM) and ascorbic acid (250 μM), nicotine (1 μM) with or without mecamylamine (5 μM) and α-bungarotoxin (0.1 μM). Keratinocyte viability and oxidative stress were evaluated by MTT and fluorescence assays. Results Pinus halepensis bark extract decreased the oxidative stress and increased the viability of keratinocytes, and moreover, these effects were more pronounced compared to the mixture of rutin and L-ascorbic acid. Nicotine significantly enhanced the viability potentiation of the beneficial effect induced by Pinus halepensis bark extract. Mecamylamine and α-bungarotoxin showed no specific effect. Conclusion Pinus halepensis bark extract in combination with nicotine may successfully reverse skin damage induced by cigarette smoke.

The aim of this work was to develop a transdermal gel formulation for enhanced delivery of candesartan. The in vitro skin permeation of the drug was examined using modified Franz type diffusion cells and epidermal membrane, taken from full thickness hairless mouse skin. Initially, a full 24 factorial design was employed, in order to estimate the effects and interactions of the following factors: the chemical form of the Active Pharmaceutical Ingredient (API), the concentration of triethanolamine (TEtA), the concentration of 1,8-cineole and the type of the vehicle's co-solvent, on the in vitro skin permeation. The experimental design revealed the optimum formulation consisting of candesartan, 5% TEtA, 10% 1,8-cineole and glycerol formal, which provided an increased flux, approximately two hundred times higher than the control formulation. Furthermore, NMR and mass spectrometry demonstrated the ion pair formation between TEtA and candesartan as an effective strategy for significantly improving its in vitro skin permeation.

The in vitro skin permeation of furosemide, a commonly used loop diuretic, through human epidermis, as a preliminary step towards the development of a transdermal therapeutic system, was examined. A screening study was carried out, in order to estimate the effects of the type, the concentration of enhancer and the concentration of gelling agent on the cumulative amount of furosemide permeated through human epidermis, using a 3(3) factorial design. The type and the concentration of enhancer were further evaluated as they were found to affect significantly furosemide permeation. In order to further increase the amount of the drug permeated, the combination of two enhancers, Azone and oleyl alcohol, at three concentration levels was employed, using an optimization technique. The results indicated that higher amounts of furosemide permeated were observed when Azone was used at 5.0-6.5% (v/v) and oleyl alcohol at 7.5-9% (v/v), in the gels used. These formulations seem to be suitable for possible transdermal delivery of furosemide for pediatric use.

In this study a complex of flurbiprofen and 2-hydroxypropyl-β-cyclodextrin (2-HPβCD), was prepared employing a freeze-drying method. The production parameters and the final specifications of this product were optimised by using response surface methodology. The results show that the freeze-dried complex meets the requirements for solubility to be considered as a possible injectable form.

The in vitro permeation of nimodipine through human cadaver skin, as a preliminary step toward the development of a transdermal therapeutic system, was investigated. In vitro release studies were carried out using modified Franz diffusion cells and human epidermal membrane, taken from full-thickness cadaver skin by heat separation technique. To estimate the effect of the type of enhancer, the concentration of enhancer and the concentration of the gelling agent on the permeation of nimodipine, a 2(3) factorial design was involved. The type of enhancer was further evaluated, because it was found to be important for the permeation of nimodipine; the concentration of enhancer and the concentration of the gelling agent were kept at their optimum levels in all experiments. Six groups of enhancers (alkanols, alkanoic acids, alkanoic acids ethyl esters, caprylic acid alkyl esters, essential oils and some other enhancers) were examined for their ability to increase the permeation of nimodipine. It was found that myristyl alcohol, caprylic acid, L-menthol, and oleic acid gave better permeation rates at 24 hr, with oleic acid being the better enhancer, and higher permeation rates at 48 and 72 hr were achieved only when cineol was used.

The steady-state blood levels of a reformulated Theophylline sustained release tablet formulation (Quibron-T/SR®) were compared with Theo-dur® tablets 300mg SR. Statistical analysis was performed, using the two one-sided tests procedure, on the In-transformed values of maximum Theophylline plasma concentrations, trough plasma concentrations and Area Under the plasma concentration - time Curve. Data regarding Time to reach maximum plasma concentration were analyzed by analysis of variance on rank transformed values. In every case, the reformulated test treatment was found within the limits required to demonstrate bioequivalence.

During the past few years, great interest was developed in the subject of floating. In the present study, the floating and swelling characteristics of several excipients used controlled release technology were examined. The floating behavior was evaluated with resultant weight measurements, while a gravimetric method was employed for studying their swelling. The experiments were carried out in two different media, i.e. deionized water and simulated meal in order to monitor possible differences. The results indicated that higher molecular weight polymers and slower rates of polymer hydration are usually followed by enhanced floating behavior. The floating characteristics of all evaluated excipients were improved when simulated meal medium was used. Finally, the combination of resultant weight measurements and swelling experiments can be used to determine in vitro the buoyancy, weight and volume changes of orally administered dosage forms and to predict floating behavior.

Betamethasone -17- Valereate release characteristics, from several commercial dermatological bases, were evaluated before and after dilution with several excipients.It was found that betamethasone releases faster from creams than from ointments. In addition the release of the corticosteroid is affected by the composition of the diluting excipient.