Efficient dermal delivery of retinyl palmitate: Progressive polarimetry and Raman spectroscopy to evaluate the structure and efficacy

Microencapsulation of alcohol solvents and high-content actives for efficient transdermal delivery

The barrier function of the skin in effectively protecting the underlying tissue from the surrounding environment makes it challenging to achieve the efficient transdermal delivery of actives. Herein, we report on alcohol-solvent-encapsulated microcapsules to achieve enhanced skin efficacy. We show that using palm oil as the shell material allows for the microencapsulation of a broad range of alcohol solvents, including ethanol and dipropylene glycol (DPG), as well as on-demand release. Moreover, clinical trials reveal that the high-content actives in microcapsules result in enhanced skin efficacy, and the presence of DPG effectively mediates the transdermal delivery of these actives without causing any skin irritation. We envision that the alcohol-solvent microencapsulation strategy outlined in this work offers new possibilities in cosmetics, food, and drug delivery systems.

Perspective of Future SERS Clinical Application Based on Current Status of Raman Spectroscopy Clinical Trials

Raman spectroscopy has emerged as a promising tool in biomedical analysis and clinical diagnosis. The development of surface-enhanced Raman scattering spectroscopy (SERS) improved the detection limit with ultrahigh sensitivity and simplicity. More and more Raman spectroscopy clinical trials (R-PCT) have been conducted recently. However, there is a lack of an up-to-date review summarizing the current status of Raman clinical trials performed until now. Hence, the clinical trials for Raman were retrieved from the International Clinical Trials Registration Platform. We summarized the clinical characteristics of 55 registered Raman spectroscopy clinical trials (R-RSCTs) and 44 published Raman spectroscopy clinical trials (P-RSCTs). This review could assist researchers and clinicians to understand the current status of Raman spectroscopy clinical research and perhaps could benefit the reasonable and accurate design of future SERS studies.

Revealing the Hidden Details of Nanostructure in a Pharmaceutical Cream

Creams are multi-component semi-solid emulsions that find widespread utility across a wide range of pharmaceutical, cosmetic, and personal care products, and they also feature prominently in veterinary preparations and processed foodstuffs. The internal architectures of these systems, however, have to date been inferred largely through macroscopic and/or indirect experimental observations and so they are not well-characterized at the molecular level. Moreover, while their long-term stability and shelf-life, and their aesthetics and functional utility are critically dependent upon their molecular structure, there is no real understanding yet of the structural mechanisms that underlie the potential destabilizing effects of additives like drugs, anti-oxidants or preservatives, and no structure-based rationale to guide product formulation. In the research reported here we sought to address these deficiencies, making particular use of small-angle neutron scattering and exploiting the device of H/D contrast variation, with complementary studies also performed using bright-field and polarised light microscopy, small-angle and wide-angle X-ray scattering, and steady-state shear rheology measurements. Through the convolved findings from these studies we have secured a finely detailed picture of the molecular structure of creams based on Aqueous Cream BP, and our findings reveal that the structure is quite different from the generic picture of cream structure that is widely accepted and reproduced in textbooks.

Oral and transdermal drug delivery systems: role of lipid-based lyotropic liquid crystals

Liquid crystal (LC) dosage forms, particularly those using lipid-based lyotropic LCs (LLCs), have generated considerable interest as potential drug delivery systems. LCs have the physical properties of liquids but retain some of the structural characteristics of crystalline solids. They are compatible with hydrophobic and hydrophilic compounds of many different classes and can protect even biologicals and nucleic acids from degradation. This review, focused on research conducted over the past 5 years, discusses the structural evaluation of LCs and their effects in drug formulations. The structural classification of LLCs into lamellar, hexagonal and micellar cubic phases is described. The structures of these phases are influenced by the addition of surfactants, which include a variety of nontoxic, biodegradable lipids; these also enhance drug solubility. LLC structure influences drug localization, particle size and viscosity, which, in turn, determine drug delivery properties. Through several specific examples, we describe the applications of LLCs in oral and topical drug formulations, the latter including transdermal and ocular delivery. In oral LLC formulations, micelle compositions and the resulting LLC structures can determine drug solubilization and stability as well as intestinal transport and absorption. Similarly, in topical LLC formulations, composition can influence whether the drug is retained in the skin or delivered transdermally. Owing to their enhancement of drug stability and promotion of controlled drug delivery, LLCs are becoming increasingly popular in pharmaceutical formulations.