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Caffeic acid (CA), a hydrophobic polyphenol with various pharmacological activities, exhibits a low aqueous solubility and sensitivity to light. In order to improve its chemical properties and overcome the limits in its application, the compound was loaded in P123 micelles (MCs) prepared using two polymer concentrations (10 and 20% w/w, MC10 and MC20). The micelles were characterised in terms of the size distribution, zeta potential, drug encapsulation efficiency, rheology, and cumulative drug release. Micellar formulations exhibited sizes in the range of 11.70 and 17.70 nm and a good polydispersion, indicating the formation of relatively small-sized micelles, which is favourable for drug delivery applications. Additionally, the stability and antioxidant profiles of the free CA and the CA loaded in micelles were studied. The results obtained on the free CA showed the formation of photodegradation products endowed with higher DPPH scavenging activity with respect to the pure compound. Instead, it was found that the incorporation of CA into the micelles significantly increased its solubility and decreased the photodegradation rate. Overall, the results indicate the successful formation of P123 micelles loaded with CA, with promising characteristics such as a small size, good encapsulation efficiency, sustained release profile, and improved light stability. These findings suggest the potentiality of these micelles as a delivery system for CA, thus enhancing its bioavailability. [ABSTRACT FROM AUTHOR]

Lidocaine is a local anaesthetic drug with an amphiphilic structure able to self-associate, under certain conditions, in molecular aggregates playing the role of both carrier and drug. The aim of this study was to determine the optimal conditions for obtaining vesicular carriers, called lidosomes. The new formulations were obtained using both lidocaine and lidocaine hydrochloride and different hydration medias (distilled water, acid, and basic aqueous solution). Lidosomes formulations were characterized in terms of size, ζ-potential, drug retained, stability formulation, and ex vivo permeation profile. Moreover, lidosomes were incorporated in two different gel structures: one based on carboxymethylcellulose and one based on pluronic F-127 to achieve suitable properties for a topical application. Results obtained showed that lidocaine showed a better performance to aggregate in vesicular carriers in respect to hydrochloride form. Consequently, only formulations comprised of lidocaine were studied in terms of skin permeation performance and as carriers of another model drug, capsaicin, for a potential combined therapy. Lidocaine, when in form of vesicular aggregates, acted as percutaneous permeation enhancer showing better permeation profiles with respect to drug solutions. Moreover, lidosomes created a significant drug depot into the skin from which the drug was available for a prolonged time, a suitable feature for a successful local therapy. [ABSTRACT FROM AUTHOR]

The natural capability shown by cationic vesicles in interacting with negatively charged surfaces or biomolecules has recently attracted increased interest. Important pharmacological advantages include the selective targeting of the tumour vasculature, the promotion of permeation across cell membranes, as well as the influence of cationic vesicles on drug delivery. Accordingly, cationic amphiphiles derived from amino acids may represent an alternative to traditional synthetic cationic surfactants due to their lower cytotoxicity. The importance of a synthesized lysine-based gemini surfactant (labelled C 6 (LL) 2 ) was evaluated in drug delivery by designing cationic niosomes as usable pharmaceutical tools of chemotherapeutics and antibiotics, respectively like methotrexate and tetracycline. The influence of formulation factors on the vesicles’ physical-chemical properties, drug entrapment efficiency, in vitro release and ex-vivo skin permeation were investigated. A niosomal gel containing the gemini surfactant was also tested as a viable multi-component topical formulation. Results indicate that in the presence of cholesterol, C 6 (LL) 2 was able to form stable and nanosized niosomes, loading hydrophilic or hydrophobic molecules. Furthermore, in vitro release studies and ex-vivo permeation profiles showed that C 6 (LL) 2 -based vesicles behave as sustained and controlled delivery systems in the case of parenteral administration, and as drug percutaneous permeation enhancers after topical application. Finally, cationic C 6 (LL) 2 acts as a carrier constituent, conferring peculiar and interesting functionality to the final formulation. [ABSTRACT FROM AUTHOR]

The aim of this study was to improve the transdermal permeation of sulfadiazine sodium, employing synergistic combination of surfactants (in the form of niosomes) and additives with different number of hydroxylic groups, (following referred to as “alcohol”), as component of the bilayer. In particular the effect of different concentration of each alcohol (ethanol, propylene glycol or glycerol, from 5%, to 40% v/v) on niosomes size and distribution, drug entrapment efficiencies and ex vivo drug percutaneous permeation were evaluated, identifying formulations giving the best performances. The findings revealed that the presence of alcohol critically affect the physico-chemical properties of niosomes, with regards to dimensions, drug encapsulation and permeation. Vesicular size increased with the amount of alcohol and at the same alcohol concentration, follow the sequence ethanol > propylene glycol > glycerol. Loaded niosomes were larger than empty ones. Low E % values were found for ethanol, even less in propylene glycol and glycerol based samples, confirming that the chemical structure of the alcohol and its physico-chemical properties, affected the sulfadiazine entrapment efficiency. The comparative evaluation of percutaneous permeation profiles showed that the cumulative amount of permeated drug increases with alcohol concentration up to 20% v/v. Higher concentration (40% v/v) resulted in a strong decrease of the potential skin permeation. Best performances were obtained with glycerol. In all cases ex vivo sulfadiazine percutaneous permeations are controlled and improved respect to the corresponding free drug solutions and traditional niosomes used as controls. [ABSTRACT FROM AUTHOR]

Abstract: A commercial sucrose cocoate surfactant was used to obtain a new vesicular system for transdermal drug delivery. The preparation, the dimensional and morphological characterizations and the skin permeation profile of these new niosomes were evaluated. Moreover we studied the possible employment of mixture of sucrose cocoate and cholesterol at different weigh ratios for the vesicles preparation and we analyzed the influence of cholesterol on niosomes properties. Diclofenac and Sulfadiazine were used as model drugs. Results suggest that sucrose cocoate was able to form vesicles in the presence or not of cholesterol and the addition of cholesterol leads to a variation of size: larger vesicles were obtained in the absence of cholesterol both in empty and drug-loaded niosomes. All vesicles were spherical and regular in shape. In vitro skin permeation profiles were significantly higher than the free drug solution, indicating the favourable relations between skin and niosomes. The faster release of the drug was found for niosomes with no cholesterol or with a reduced amount of this membrane additive, in particular the optimal formulation was that in which the cholesterol content was about 27wt% of total lipid amount: probably this value is a good compromise between the membrane stability and its deformation capacity, allowing a higher drug permeation across the skin. [Copyright &y& Elsevier]

Simvastatin (SIM) is a HMG-CoA reductase inhibitor employed in the management of hyperlipidemia. However, its low bioavailability limits its clinical efficacy. The objective of this study was to overcome the poor bioavailability of SIM via the transdermal application of a SIM-loaded niosomal gel. Niosomes loaded with SIM were fabricated by means of the thin-film hydration method and optimized through a 33-factorial design utilizing Design Expert® software. The prepared niosomes were evaluated for entrapment efficiency (EE%), zeta potential, vesicle size, and cumulative percentage of drug release. The optimum niosomal formulation was loaded on the gel and evaluated for physical properties such as color, clarity, and homogeneity. It was also evaluated for spreadability, and the cumulative % drug release. The best niosomal gel formula was appraised for ex vivo permeation as well as pharmacokinetic study. The SIM-loaded niosomes showed EE% between 66.7–91.4%, vesicle size between 191.1–521.6 nm, and zeta potential ranged between −0.81–+35.6 mv. The cumulative percentage of drug released was ranged from 55% to 94% over 12 h. SIM-loaded niosomal gels were clear, homogenous, spreadable, and the pH values were within the range of physiological skin pH. Furthermore, about 73.5% of SIM was released within 24 h, whereas 409.5 µg/cm2 of SIM passed through the skin over 24 h in the ex vivo permeation study. The pharmacokinetic study revealed higher AUC0–∞ and Cmax with topical application of SIM-loaded niosomal gel compared to topical SIM gel or oral SIM suspension. The topical application of SIM-loaded niosomal gel ascertained the potential percutaneous delivery of SIM. [ABSTRACT FROM AUTHOR]