Semifluorinated Alkanes as New Drug Carriers-An Overview of Potential Medical and Clinical Applications

Comparative Efficacy of Current Topical Treatments for Dry Eye Disease: A Review of Pivotal Clinical Trials Evaluating Corneal Staining Outcomes

Dry eye disease (DED) is a multifactorial disorder characterized by disruption of tear film homeostasis, resulting in ocular surface inflammation and damage. Although several Food and Drug Administration-approved topical treatments are available, direct comparisons of their efficacy and safety are complicated by variability in study designs and corneal staining grading scales. This review systematically evaluates and compares the efficacy and safety of topical therapies approved in the United States, focusing on anti-inflammatory and semi-fluorinated alkane (SFA)-based therapies. A systematic literature review identified 12 randomized controlled trials involving a total of 6,984 patients with varying severity of DED eligible for inclusion, with 8 providing data suitable for quantitative meta-analysis and 5 for exploratory regression analysis. Meta-analysis indicated that cyclosporine 0.1%/SFA showed the most significant early improvement (within ≤4 weeks) in total corneal fluorescein staining, outperforming other treatments. Exploratory regression analysis further supported these findings, demonstrating that cyclosporine 0.1%/SFA had the fastest and most consistent reduction in corneal staining, with the steepest improvement slope and strong predictability (R2 = 0.871). Safety analyses highlighted improved local tolerability for SFA-based therapies compared with traditional anti-inflammatory treatments, notably lower instillation site discomfort for both cyclosporine 0.1%/SFA (2.5%-9.9%) and perfluorohexyloctane (≤1%) vs. other cyclosporine formulations. SFA-based therapies, especially cyclosporine 0.1%/SFA, demostrated robust efficacy in improving signs of DED with superior tolerability profiles compared to traditional anti-inflammatory treatments. These findings support the role in effectively managing ocular surface inflammation and optimizing treatment strategies in DED.

Propofol: Current Updates, Challenges, and Strategies for Improved Self-Nanoemulsifying Formulation

Propofol, commonly used as an intravenous (IV) anesthetic and sedative, requires strict aseptic handling to prevent microbial contamination. There have been alarming reports of bloodborne pathogen transmission due to unsafe injection practices and the reuse of single-use propofol vials. Additionally, managing pain during anesthesia induction and determining the correct dose for sedation pose significant challenges with IV propofol. Despite its effectiveness, propofol's limited water solubility and poor oral bioavailability restrict its use outside of anesthesia. Understanding how propofol works remains complex. Advances in nanotechnology have significantly improved the bioavailability of hydrophobic drugs through self-nanoemulsifying drug delivery systems (SNEDDS). These lipid-based formulations create nanoscale emulsions upon contact with gastrointestinal fluids, enhancing drug solubilization and absorption. For instance, studies have shown that SNEDDS can improve bioavailability by 2- to 3-fold compared to traditional formulations, as demonstrated with drugs such as propofol, whose poor water solubility limits its therapeutic efficiency. This review delves into propofol's chemical properties, pharmacokinetics, and pharmacodynamics, evaluating the potential of SNEDDS to address its formulation challenges and discussing promising candidates in clinical trials. Furthermore, it examines the potential of using SNEDDS to improve propofol's bioavailability through nonintravenous routes. This review highlights the potential of SNEDDS to enhance propofol's therapeutic effectiveness beyond its traditional use in anesthesia, opening new avenues for its application.

Differentiating Between Perfluorohexyloctane Ophthalmic Solution and Water-Free Cyclosporine Ophthalmic Solution 0.1% for Dry Eye Disease: A Review of Preclinical and Clinical Characteristics

Perfluorohexyloctane ophthalmic solution (Miebo) and water-free cyclosporine ophthalmic solution 0.1% (Vevye) are recently approved treatments for dry eye disease (DED). Perfluorohexyloctane (PFHO) uses a novel approach to treat evaporative DED, whereas water-free cyclosporine (CsA 0.1%) is formulated to increase ocular delivery of its active ingredient to improve tear production. The two medications utilize the distinctive properties of two different semifluorinated alkanes (SFAs) to elicit their therapeutic effects. PFHO consists of 100% active ingredient and forms a monolayer on the surface of the tear film to inhibit evaporation. CsA 0.1% utilizes a vehicle consisting of perfluorobutylpentane (PFBP) and ethanol to facilitate delivery of cyclosporine to ocular tissues. The structure of these SFAs determines their differing behaviors and functions. The longer chain length of PFHO results in a slower evaporation rate and facilitates formation of a stable monolayer on the ocular surface. In vitro, PFHO demonstrated a substantially lower evaporation rate versus PFBP or human meibum, as well as a significantly longer ocular surface residence time. Ex vivo, PFHO demonstrated a longer ocular surface residence time than PFBP. The shorter chain length of PFBP enables it to better solubilize cyclosporine and improve drug delivery to ocular tissues. Although both of these ophthalmic drops utilize SFAs, their differences-in physicochemical properties and the mechanisms by which they are understood to intervene in the DED cycle-are important considerations in treatment selection for patients with DED.

Investigating the degradation potential of microbial consortia for perfluorooctane sulfonate through a functional "top-down" screening approach

Perfluorooctane sulfonate (PFOS) is a prominent perfluorinated compound commonly found in the environment, known to pose various risks to human health. However, the removal of PFOS presents significant challenges, primarily due to the limited discovery of bacteria capable of effectively degrading PFOS. Moreover, single degradation bacteria often encounter obstacles in individual cultivation and the breakdown of complex pollutants. In contrast, microbial consortia have shown promise in pollutant degradation. This study employed a continuous enrichment method, combined with multiple co-metabolic substrates, to investigate a microbial consortium with the potential for PFOS degradation. By employing this methodology, we effectively identified a microbial consortium that demonstrated the capacity to reduce PFOS when exposed to an optimal concentration of methanol. The consortium predominantly comprised of Hyphomicrobium species (46.7%) along with unclassified microorganisms (53.0%). Over a duration of 20 days, the PFOS concentration exhibited a notable decrease of 56.7% in comparison to the initial level, while considering the exclusion of adsorption effects. Furthermore, by comparing the predicted metabolic pathways of the microbial consortium with the genome of a known chloromethane-degrading bacterium, Hyphomicrobium sp. MC1, using the KEGG database, we observed distinct variations in the metabolic pathways, suggesting the potential role of the unclassified microorganisms. These findings underscore the potential effectiveness of a "top-down" functional microbial screening approach in the degradation of stubborn pollutants.

10-Phenylphenothiazine-Organophotocatalyzed Bromo-Perfluoroalkylation of Unactivated Olefins

In this study, we have developed a smooth metal-free visible-light-induced bromo-perfluoroalkylation of unactivated olefins with the aid of 10-phenylphenothiazine (PTH) as an organic photoredox catalyst. The reaction is 100% atom-economic redox-neutral and proceeds with stoichiometric amounts of olefin and perfluoroalkyl bromide. To show the potential of these unexplored motifs, we carried out various postfunctionalizations taking advantage of the bromine atom, including gram-scale experiments.

Perfluorohexyloctane Ophthalmic Solution: A Review in Dry Eye Disease

Perfluorohexyloctane ophthalmic solution (Miebo®) is a single-entity, water-, steroid- and preservative-free, first-in-class semifluorinated alkane that is approved in the USA for the treatment of the signs and symptoms of dry eye disease (DED). DED is often linked with meibomian gland dysfunction (MGD), which causes an excessive evaporation of tears. Perfluorohexyloctane ophthalmic solution stabilizes the lipid layer of the tear film and inhibits tear evaporation by forming a monolayer at the air-liquid interface. In the phase III GOBI and MOJAVE trials in adults with DED associated with MGD, one drop of perfluorohexyloctane ophthalmic solution instilled in each eye four times daily over 8 weeks resulted in statistically significant and clinically meaningful improvements in the signs and symptoms of DED compared with hypotonic saline (0.6%). The agent was generally well tolerated, with most ocular adverse events being mild or moderate in severity. The efficacy and tolerability of perfluorohexyloctane ophthalmic solution was sustained for up to 52 weeks in an extension study (KALAHARI). As the first and currently the only prescription treatment approved in the USA directly addressing the pathophysiology of excessive tear evaporation, perfluorohexyloctane ophthalmic solution is a valuable emerging option for the management of DED.

Topical ocular protein delivery based on protein powder suspensions in semifluorinated alkanes

The field of ocular diseases, specifically retinal diseases is a successful target area for protein drugs with various marketed products. Besides the intraocular treatment of the retina, the topical treatment of corneal or conjunctival diseases is a promising approach. Topical ocular protein formulations face the challenges of poor penetration and potentially low stability. In this study we tested suspensions based on the semifluorinated alkane F6H8 to improve the topical ocular protein delivery. Such suspensions are well known for the increased protein stability compared to aqueous solutions. Furthermore, F6H8 is well known as vehicle for ocular delivery due to its easy spreading on the cornea. Penetration of a model mAb and its Fab fragment was tested in an ex vivo corneal penetration test. The amount of penetrated protein was increased when the protein powder suspensions were used compared to the respective aqueous solutions. Sodium caprate as penetration enhancer at 5mg/ml substantially increased the Fab fragment (7-fold) and the mAB (3-fold) concentration in the corneal tissue when applied as an aqueous solution. The effect was surprisingly more pronounced, when Fab fragment (31-fold) or mAb (13-fold) and the penetration enhancer were formulated as F6H8 suspensions. The same penetration enhancement from suspensions could be achieved with 2.5mg/ml, but the penetration was reduced compared to 2.5 mg/ml in the aqueous solution. A test based on stratified human keratinocytes did not indicate eye irritation by the tested formulations. Furthermore, stability studies for bevacizumab suspensions in semifluorinated alkanes were investigated and showed superior long-term stability compared to the marketed aqueous solution. Overall results demonstrate the high potential of topical ocular protein delivery using powder suspensions in non-aqueous vehicles based on semifluorinated alkanes.