Abstract. L-ascorbic acid has been widely used in cosmetic and dermatological products because of its ability to scavenge free radicals and destroy oxidizing agents. However, it is chemically unstable and can easily be oxidized. The current cosmetic facial masks available in the market are pre-moistened, which means that the aqueous fluid content of the mask may oxidize some of the unstable active ingredients such as ascorbic acid. This work presents an anti-wrinkle nanofiber face mask containing ascorbic acid, retinoic acid, gold nanoparticles, and collagen. This novel face mask will only be wetted when applied to the skin, thus enhancing product stability. Once moistened, the content of the mask will gradually dissolve and release the active ingredients and ensure maximum skin penetration. The high surface areato-volume ratio of the nanofiber mask will ensure maximum contact with the skin surface and help to enhance the skin permeation to restore its healthy appearance. Electrospun fiber mats may provide an attractive alternative to the commercial facial cotton masks.

-Surface chemistry has a large influence in many industries. In the life sciences, surface area is gaining importance in the characterization of materials during their development, formulation and manufacturing. The chemical activity, adsorption, dissolution, and bioavailability of a drug may depend on the surface of the molecule. In order to meet manufacturing challenges and develop new and better performing products with improved qualities, knowledge of surface tension is of utmost importance. An attempt has been made in this paper to review the application of interfacial tension in the key domains of pharmaceutical applications.

Introduction: Pathological features of disease appear to be quite different. Despite this diversity, the common feature of various disorders underlies physicochemical and biochemical factors such as surface tension. Human biological fluids comprise various proteins and phospholipids which are capable of adsorption at fluid interfaces and play a vital role in the physiological function of human organs. Surface tension of body fluids correlates directly to the development of pathological states. Methods: In this review, the variety of human diseases mediated by the surface tension changes of biological phenomena and the failure of biological fluids to remain in their native state are discussed. Results: Dynamic surface tension measurements of human biological fluids depend on various parameters such as sex, age and changes during pregnancy or certain disease. It is expected that studies of surface tension behavior of human biological fluids will provide additional information and might become useful in medical practice. Theoretical background on surface tension measurement and surface tension values of reference fluids obtained from healthy and sick patients are depicted. Conclusion: It is well accepted that no single biomarker will be effective in clinical diagnosis. The surface tension measurement combined with routine lab tests may be a novel non-invasive method which can not only facilitate the discovery of diagnostic models for various diseases and its severity, but also be a useful tool for monitoring treatment efficacy. We therefore expect that studies of surface tension behavior of human biological fluids will provide additional useful information in medical practice.

Topical administration of levothyroxine (T4) helps to reduces deposits of adipose tissue on skin. The question is whether topical application of T4 could lead to systemic effects. In the present study a series of nanofibrous membranes were electrospun into blends of poly vinyl alcohol (PVA) and poly-N-isopropylacrylamide (PNIPAM) to develop a sustained topical delivery of T4. The polymeric nanofiber mats were characterized by field emission scanning electron microscopy (FESEM) and fourier transform infrared (FTIR) spectroscopy. In vitro permeation of the drug from the polymeric nanofibers was studied using excised human skin and the permeation mechanism investigated using confocal microscopy. It was observed that polymeric nanofibers were able to sustain the penetration of T4 to the skin and help maintain the effective drug concentration in the skin layers for longer period of time. These formulations may have potential uses in topical skin products and can help to increase the accumulation of the active compound on the skin surface thus minimize the adverse side effects which may be caused by systemic absorption. This may result in great improvement in consumer compliance, avoid frequent dosing and enhance the therapeutic effectiveness.

Surface and/or interfacial tension is a measurable quantity, which represents the surface and/or interfacial activity and differs from the assumed ideal value when the system becomes non-ideal. Surface tension plays an important role in the functioning of respiratory system. Surface tension of the fluid lining the alveoli is decreased by a mixture of surface active agents mainly, dipalmitoyl lecithin. Respiratory distress syndrome and atelectasis are two major clinical syndromes of increasing the surface tension of the fluid lining the alveoli. 1) Prokop et al. 2) reported the relationships between recoil pressure and surface area of the lung and the surface tension of the lung fluid. Several important phenomena in the pharmaceutical and analytical areas are related to the surface activity. This includes suspension and emulsion formulations, solubilization techniques and explaining the retention mechanisms in HPLC. The primary droplet size of the nebulized solutions was correlated to the surface tension of the solution.3) Binary and ternary solvents have been used in many pharmaceutical formulations and also validated analytical methods at ambient and higher and/or lower temperatures. The surface tension data of mixed solvents are required in practice and the aim of this work is to present a simple mathematical model for calculating such data. Computational MethodsThe basic solution model, i.e. the combined nearly ideal binary solvent/Redlich-Kister equation (CNIBS/R-K), presented by Acree 4) was used to correlate different physico-chemical properties in mixed solvent systems; including the solubility of drugs in water-cosolvent mixtures, 5) electrophoretic mobility of analytes in mixed solvent electrolyte systems, 6-8) the instability rate constants in binary solvent systems, 9) the acid dissociation constants in water-organic solvent mixtures, 10) the dielectric constant 11) and surface tension 12) of solvent mixtures. Theoretical basis of the CNIBS/R-K equation for describing the chemical potential of solutes dissolved in mixed solvents 4) and acid dissociation constants in aqueous-organic mixtures 10) have been provided in earlier papers.The Jouyban-Acree model (JAM) representing the surface tension of binary solvent mixtures at a constant temperature has been proposed in our earlier work 12) as:( 1) Where g m , g 1 and g 2 are the surface tensions of the mixture and solvents 1 and 2, respectively, f 1 and f 2 are the volume (weight or mole) fractions of solvents 1 and 2 in the mixture and K i represent the model constants calculated using a least square method. 13) The model could be extended for calculating the surface tension of ternary solvents as: 12)To correlate the surface tensions of binary solvents at various temperatures (T), an extended form of JAM could be used for calculating the surface tension with respect to solvent composition and temperature, and is proposed in this work as: (3) Where g m,T , g 1,T and g 2,T are the surface tensions of the mixture and solvents 1 and 2 at temperature T, re...