An Overview on Topical Administration of Carotenoids and Coenzyme Q10 Loaded in Lipid Nanoparticles.

Carotenoids and coenzyme Q10 are naturally occurring antioxidant compounds that are also found in human skin. These bioactive compounds have been the focus of considerable research due to their antioxidant, anti-inflammatory, and photoprotective properties. In this review, the current state of the art in the encapsulation of carotenoids and coenzyme Q10 in lipid nanoparticles to improve their bioavailability, chemical stability, and skin absorption is discussed. Additionally, the main findings are highlighted on the cytotoxic and photoprotective effects of these systems in the skin.

Acoustic levitation and high-resolution synchrotron X-ray powder diffraction: A fast screening approach of niclosamide amorphous solid dispersions.

The levitation of samples in an acoustic field has been of interest in the preparation and study of amorphous solid dispersions (ASD). Here, niclosamide-polymer solutions were levitated in a multi-emitter single-axis acoustic levitator and analyzed for 10 min at a High-resolution synchrotron X-ray powder diffraction beamline. This assembly enabled high-quality and fast time-resolved measurements with microliter sample size and measurement of solvent evaporation and recrystallization of niclosamide (NCL). Polymers HPMCP-55S, HPMCP-50, HPMCP-55, Klucel®, and poloxamers were not able to form amorphous dispersions with NCL. Plasdone® and Soluplus® demonstrated excellent properties to form NCL amorphous dispersions, with the last showing superior solubility enhancement. Furthermore, this fast levitation polymer screening showed good agreement with results obtained by conventional solvent evaporation screening evaluated for five days in a stability study, carried out at 40 °C/75% RH. The study showed that acoustic levitation and high-resolution synchrotron combination opens up a new horizon with great potential for accelerating ASD formulation screening and analysis.

Exploratory Study on Lercanidipine Hydrochloride Polymorphism: pH-Dependent Solubility Behavior and Simulation of its Impact on Pharmacokinetics.

This work describes an exploratory experimental and in silico study of the influence of polymorphism, particle size, and physiology on the pharmacokinetics of lercanidipine hydrochloride (LHC). Equilibrium and kinetic solubility studies were performed on LHC forms I and II, as a function of pH and buffer composition. GastroPlus® was used to evaluate the potential effect of solubility differences due to polymorphism, particle size, and physiological conditions, on the drug pharmacokinetics. The results indicated that solubilities of LHC polymorphs are strongly dependent on the composition and pH of the buffer media. The concentration ratio (CI/CII) is particularly large for chloride buffer (CI/CII = 3.3-3.9) and exhibits a slightly decreasing tendency with the pH increase for all other buffers. Based on solubility alone, a higher bioavailability of form I might be expected. However, exploratory PBPK simulations suggested that (i) under usual fasted (pH 1.3) and fed (pH 4.9) gastric conditions, the two polymorphs have similar bioavailability, regardless of the particle size; (ii) at high gastric pH in the fasted state (e.g., pH 3.0), the bioavailability of form II can be considerably lower than that of form I, unless the particle size is < 20 µm. This study demonstrates the importance of investigating the effect of the buffer nature when evaluating the solubility of ionizable polymorphic substances. It also showcases the benefits of using PBPK simulations, to assess the risk and pharmacokinetic relevance of different solubility and particle size between crystal forms, for diverse physiological conditions.

Anti-inflammatory drug nanocrystals: state of art and regulatory perspective.

Anti-inflammatory drugs have been prescribed extensively for a wide range of diseases. Combined with over-the-counter use, approximately 30 billion doses of non-steroidal inflammatory drugs (NSAIDs) are consumed annually in the USA. The global market of glucocorticoids (GCs) is forecast to reach US$ 8.6 billion by 2025. Severe adverse effects have been reported for NSAIDs, GCs, and COX-2 selective NSAIDs (COXIBs). Furthermore, the overwhelming majority of these drug substances are BCS class II, which limits their bioavailability due to poor water solubility. Drug nanocrystals, a carrier-free nanosystem, can increase saturation solubility, dissolution rate, and the mucoadhesiveness of these drugs. The enhancement of these properties was highlighted in our findings. These features improve the efficacy and safety of anti-inflammatory drugs. In this review, we show that drug nanocrystals are an attractive strategy that contributes to an important shift in the development of innovative products for different routes of administration. The possibility of targeting can minimize the adverse effects and improve the efficacy in the management of inflammatory conditions. We comprehensively review the critical quality attributes (CQAs) in the anti-inflammatory drug nanocrystals preparation, which are fundamental to developing a successful marketable product. Despite the advantages, maintaining properties such as average particle size, surface properties, and physicochemical stability of these preparations during shelf life poses challenges to be overcome.

Influence of Shea (Butyrospermum parkii) butter, TiO2 and ethylhexyl methoxycinnamate on physical parameters and in vitro photoprotective efficacy.

BACKGROUND: The development of photoprotective lipsticks containing natural bioactive compounds is a relevant current strategy to increase sun protection factor (SPF) value and lower the concentration of chemical UV filters, known for promoting sensitivity reactions. AIMS: Twelve photoprotective lipsticks were developed by Design of Experiment (DOE) and characterized to verify the influence of Shea butter (Butyrospermum parkii), titanium dioxide (TiO2 ), and ethylhexyl methoxycinnamate (EHM) on physical parameters and in vitro photoprotective efficacy. METHODS: The influence of Shea butter, TiO2, and EHM was evaluated by several parameters, such as melting point, colorimetry, thermal analysis by DSC, texture analysis, and sunscreen activity estimated in vitro. RESULTS: The construction of prediction models was possible for the following responses: maximum force by the cantilever test at 25 and 45°C; maximum distance by hardness test at 25°C; slope value at 25 and 45°C by the cantilever test; and UVA/UVB ratio and in vitro SPF. TiO2 and EHM contributed to changes on the in vitro SPF value; however, unexpectedly, Shea butter had no influence on this efficacy parameter. CONCLUSION: The assay allowed us to observe the influence of the variables in the analysis and to develop a response prediction model for some of the parameters assessed.

Development of cationic nanocrystals for ocular delivery.

A cationic nanocrystal formulation containing dexamethasone acetate nanocrystals (0.05%) and polymyxin B (0.10%) for ophthalmic application was produced using a self-developed small scale method for wet bead milling. The formulation developed offers the advantage of increased saturation solubility of the drug (due to the nano-size of the crystals) and increased residence time in the eye (due to small size and increased mucoadhesion by the cationic charge) resulting ultimately in potential increased bioavailability. Characterization of the nanosuspensions by photon correlation spectroscopy (PCS) and transmission electron microscopy showed that the production method was successful in achieving dexamethasone crystals in the range of about 200-250nm. The physical stabilization of the nanocrystals and generation of the positive charge were realized by using cetylpyridinium chloride (CPC) and benzalkonium chloride (BAC) at the concentration of 0.01%. In contrast to other cationic excipients, they are regulatorily accepted due to their use as preservatives. The drug polymyxin B also contributed to the positive charge. Positive zeta potentials in the range +20 to +30mV were achieved. Isotonicity was adjusted using NaCl and non-ionic excipients (glycerol, sorbitol, dextrose). Physical and chemical stabilities were monitored for a period of 6months at room temperature, 5°C and 40°C. Particle size of the bulk population assessed by PCS remained practically unchanged over 6months of storage for the various formulations without isotonicity agents, and for the CPC-containing formulations with non-ionic isotonicity excipients. The chemical content also proved stable after 6months for all 3 temperatures evaluated. In vitro investigation of mucoadhesion was tested using mucin solutions at different concentrations, and the generated negative zeta potential was used as a measure of the interaction. The zeta potential reversed to about -15mV, indicating distinct interaction. The results show the potential of increased mucoadhesion of such cationic nanocrystals compared to standard eye drop formulations. The positively charged nanocrystal formulation also showed no in vitro cytotoxicity as assessed on fibroblast cell culture. In summary, 3 formulation candidates were identified being a promising alternative for ocular delivery with increased performance compared to what is presently available.

Preparation and characterization of a microencapsulated polyethylene glycol cross-linked polyhemoglobin.

Many complications are associated to the therapeutic use of blood, among which are not only transfusion adverse events but also other issues such as lack of donors and high costs for collecting, testing, preserving, and distributing blood packages. Therefore, a clinically viable "blood substitute" is considered the holy grail of traumatology and may greatly benefit medicine. One of the most successful approaches to date is conjugating hemoglobin with polyethylene glycol (PEG). This conjugation aims mainly at overcoming free cell hemoglobin toxicity, which makes its use as oxygen carrier in pure form unfeasible. To improve PEG-hemoglobin conjugates feasibility, we propose applying dual functional PEG cross-linking hemoglobin molecules encapsulated by a protein carrier. The new oxygen carrier showed mean values of the hydrodynamic diameter, dispersity, and zeta potential of 1370 nm, 0.029 and -36 mV, respectively, evidencing the successful synthesis of PEG bis(N-succinimidyl succinate) and polyhemoglobin as well as the structuring of protein carrier.

Evaluation of preservative systems in a sunscreen formula by linear regression method.

A sunscreen formula with eight different preservative systems was evaluated by linear regression, pharmacopeial, and the CTFA (Cosmetic, Toiletry and Fragrance Association) methods. The preparations were tested against Staphylococcus aureus, Burkholderia cepacia, Shewanella putrefaciens, Escherichia coli, and Bacillus sp. The linear regression method proved to be useful in the selection of the most effective preservative system used in cosmetic formulation.