Environmental impacts due to the use of sunscreen products: a mini-review

Sunscreen use has increased in recent years, as sunscreen products minimize the damaging effects of solar radiation. Active ingredients called ultraviolet (UV) filters or UV agents, either organic or inorganic, responsible for defending skin tissue against harmful UV rays, are incorporated in sunscreen formulations. UV agents have a serious impact on many members of bio communities, and they are transferred to the environment either directly or indirectly. Many organic UV filters are found to be accumulated in marine environments because of high values of the octanol/water partition coefficient. However, due to the fact that UV agents are not stable in water, unwanted by-products may be formed. Experimental studies or field observations have shown that organic UV filters tend to bioaccumulate in various aquatic animals, such as corals, algae, arthropods, mollusks, echinoderms, marine vertebrates. This review was conducted in order to understand the effects of UV agents on both the environment and marine biota. In vivo and in vitro studies of UV filters show a wide range of adverse effects on the environment and exposed organisms. Coral bleaching receives considerable attention, but the scientific data identify potential toxicities of endocrine, neurologic, neoplastic and developmental pathways. However, more controlled environmental studies and long-term human use data are limited. Several jurisdictions have prohibited specific UV filters, but this does not adequately address the dichotomy of the benefits of photoprotection vs lack of eco-friendly, safe, and approved alternatives.

Modified release of acetaminophen from matrix tablet formulations: Influence of tablet geometry

Background:

Acetaminophen (APAP) or otherwise called paracetamol is a widely used over-the-counter, analgesic (common conditions treated include headaches, backache, toothache, muscle aches, arthritis, sore throat etc.) and antipyretic drug. It can be administered orally, in the form of a tablet (plain, effervescent, orodispersable, etc.) or liquid, rectally in the form of suppository or by injection (intravenously or intramuscularly). It is well absorbed orally with a plasma elimination half-life ranging from 1 to 4 h. The modified release oral formulation can prolong its therapeutic effects by maintaining APAP average plasma concentrations.

Objective:

In the context of this work, two APAP formulation tablets with different geometries were produced from standard pharmaceutical excipients, to investigate the role of altered tablet geometry in modified oral drug delivery.

Methods:

APAP tablets were prepared by direct compression, using hydroxypropyl methylcellulose (HPMC K15M), polyvinylpyrrolidone (PVP, MW: 55,000) and magnesium stearate, as ingredients. The release profiles were probed in aqueous dissolution media (pH 1.2 and 6.8), to simulate the conditions in the gastrointestinal tract, in a United States Pharmacopeia (USP) dissolution paddle apparatus II and analyzed using a ultraviolet (UV) spectrophotometer (λmax = 244 nm).

Results:

The results indicated that the tablets were within the acceptable range of all evaluation parameters (tablet dimensions, drug content, weight variation, and breaking force) as defined by the international standards stated in the US Pharmacopoeia. The dissolution results showed that the APAP’s release profile was controlled by the tablets’ different geometries and specifically the surface area (SA) and the surface area/volume (SA/V) ratio of the different tablets. The tablets with smaller SA/V ratios and SA showed slower drug release, indicative of a modified release motif.

Conclusion:

Altered tablet geometry plays an important role in APAP modified oral drug delivery.

Excipients Used for Modified Nasal Drug Delivery: A Mini-Review of the Recent Advances

The ongoing challenging task in the field of nasal drug delivery is the maintenance of an efficient concentration of the active substance in the target area for an adequate period of time. Thus, there is an urgent need to develop effective new strategies for drug delivery to the nose, using cutting edge technology and materials for this particular type of drug delivery. This review gives an account of the critical components of nasal drug delivery and the parameters influencing drug absorption in the nose, including the excipients required for modified drug administration.

Recent Advances in the Excipients Used in Modified Release Vaginal Formulations

The formulation of an ideal vaginal drug delivery system (DDS), with the requisite properties, with respect to safety, efficacy, patient compliance, aesthetics, harmonization with the regulatory requirements, and cost, requires a meticulous selection of the active ingredients and the excipients used. Novel excipients defined by diversity and multifunctionality are used in order to ameliorate drug delivery attributes. Synthetic and natural polymers are broadly used in pharmaceutical vaginal formulations (solid, semi-solid dosage forms, implantable devices, and nanomedicines) with a promising perspective in improving stability and compatibility issues when administered topically or systemically. Moreover, the use of biopolymers is aiming towards formulating novel bioactive, biocompatible, and biodegradable DDSs with a controllable drug release rate. Overviewing vaginal microenvironment, which is described by variable and perplexed features, a perceptive choice of excipients is essential. This review summarizes the recent advances on the excipients used in modified vaginal drug delivery formulations, in an attempt to aid the formulation scientist in selecting the optimal excipients for the preparation of vaginal products.

Recent Advances in the Excipients Used for Modified Ocular Drug Delivery

In ocular drug delivery, maintaining an efficient concentration of the drug in the target area for a sufficient period of time is a challenging task. There is a pressing need for the development of effective strategies for drug delivery to the eye using recent advances in material sciences and novel approaches to drug delivery. This review summarizes the important aspects of ocular drug delivery and the factors affecting drug absorption in the eye including encapsulating excipients (chitosan, hyaluronic acid, poloxamer, PLGA, PVCL-PVA-PEG, cetalkonium chloride, and gelatin) for modified drug delivery.

UV Filters and Their Distribution on the Skin through Safe, Non-Penetrating Vehicles

The effects of ultraviolet (UV) radiation trigger human skin reaction, which can result in erythema, photoaging, and/or skin cancer. Sunscreens play an important role against the negative effects of UV radiation on the human skin. However, they should satisfy certain criteria, with the main one being photostability, to avoid the formation of health-threatening reactive intermediates. It has to be kept in mind, however, that photo-stable UV filters have the undesirable propensity to transfer energy to molecular oxygen and generate the very reactive singlet oxygen. They should also be well tolerated, while at the same time, they should not permeate into the skin and cause toxic effects. Thus, there is an ongoing need to develop effective and safe non-penetrating sunscreen formulations. The search for innovative active substances, efficacious combinations, and the design of vehicles or carriers has led to the implementation of advanced delivery systems. This study intended to review the commonly used UV radiation thwarting agents (organic and inorganic UV filters), compile the relevant toxicity studies, evaluate their margin of safety, and assess the current situation on innovative sunscreen formulations.

Worldwide actions against plastic pollution from microbeads and microplastics in cosmetics focusing on European policies. Has the issue been handled effectively?

Microbeads are solid primary microplastics < 5 mm in diameter that are added to cosmetic products for cleansing and/or exfoliation of the skin. After use, they are discharged into the drain and end up in Wastewater Treatment Plants (WWTPs), from which they can escape into waters. Once disposed, there is no efficient method of recovery and the environmental conditions do not allow full biodegradation. Focusing mainly on the possible effect of microbeads on the environment and the human health, and taking into account that there have always been alternatives with similar cost, scientists suggested banning microbeads from cosmetic products. Despite the increasing knowledge on the microplastics' effects, the pressure from non-governmental organizations (NGO's) and the increasing public concern, few European and other countries worldwide have taken legislative steps against microbeads, and even fewer against other microplastics used in cosmetic products, mainly because it is a common belief that cosmetic industries responded massively to the call for a phase-out. Although EU acted soon after scientists focused on microbeads' effects by restricting cosmetics with microbeads to bare the EU Ecolabel in 2014, there is still no European-wide ban, which will probably take place as of 2022. Present study offers a thorough literature review on the presence of microbeads in cosmetics up to date, focusing primarily on the actions against their use, and questioning whether future pollution from microbeads or/and microplastics in cosmetics has been successfully handled.

Protective Effects of Pinus halepensis Bark Extract and Nicotine on Cigarette Smoke-induced Oxidative Stress in Keratinocytes

BACKGROUND/AIM

Cigarette smoke (CS) is a major environmental health threat. The oxidative stress induced by CS on keratinocytes and the possible protective effect of nicotine, its receptor inhibitors, and Pinus halepensis bark extract in relation to known antioxidants were investigated.

MATERIALS AND METHODS

Primary mouse keratinocytes were exposed to cigarette smoke in the presence and absence of Pinus halepensis bark extract (1 μg/ml), rutin (50 μM) and ascorbic acid (250 μM), nicotine (1 μM) with or without mecamylamine (5 μM) and α-bungarotoxin (0.1 μM). Keratinocyte viability and oxidative stress were evaluated by MTT and fluorescence assays.

RESULTS

Pinus halepensis bark extract decreased the oxidative stress and increased the viability of keratinocytes, and moreover, these effects were more pronounced compared to the mixture of rutin and L-ascorbic acid. Nicotine significantly enhanced the viability potentiation of the beneficial effect induced by Pinus halepensis bark extract. Mecamylamine and α-bungarotoxin showed no specific effect.

CONCLUSION

Pinus halepensis bark extract in combination with nicotine may successfully reverse skin damage induced by cigarette smoke.

Topical Treatment of Skin Injury Inflicted in Mice by X-Ray Irradiation

BACKGROUND/AIMS

There is no treatment, without side effects, efficiently preventing or curing skin burns, caused by radiotherapy. A new experimental topical treatment protocol was assessed in mice receiving orthovoltage X-rays at an equivalent dose to that applied to human breast cancer patients in conventional radiotherapy.

METHODS

SKH-HR2 female hairless mice were irradiated on their dorsum with a total dose of 4,300 cGy during a 1-month period (20 fractions). The treatment group received a combination of 3 topical products, an oil-in-water cream, a gel containing Pinus halepensis bark aqueous extract, and an ointment containing olive oil extract of the marine isopod Ceratothoa oestroides. The positive control group was treated with a conventionally used commercial gel, whereas the negative control group did not receive any topical treatment. Skin alterations were evaluated by macroscopic examinations, measurements of transepidermal water loss (TEWL), melanin content, erythema intensity, hydration, and histopathology assessment.

RESULTS

Sixty days after radiation, TEWL and hydration values were abnormal and elements of acute, chronic, and granulomatous inflammation were present in all cases. The severest damage was detected in the deeper dermis. Treatment showed a comparatively beneficial effect on chronic and granulomatous inflammation while positive control was beneficial on acute inflammation.

CONCLUSION

Skin anti-inflammatory treatment was the most effective but must be applied for several months. Further preclinical studies should be conducted, assimilating a human cancer radiation therapeutic schema with the aim of optimizing skin inflammation treatment.

Alitretinoin: a useful agent in the treatment of hidradenitis suppurativa, especially in women of child-bearing age

AIM

Despite a better insight into its pathogenesis, hidradenitis suppurativa (HS) remains very frustrating to treat. Acitretin has been described as one of the agents with the highest effective profile. Acitretin however, due to its teratogenicity and prolonged half-life (up to three years) is not an option in young women of fertile age who, unfortunately, are the target of this disease. Alitretinoin has a similar pharmacology action to acitretin, but much shorter half-life (only four weeks), making it a far much more attractive option compared to acitretin for women of child-bearing age. The aim of this paper was to evaluate the use of alitretinoin in treating recalcitrant cases of HS, which have not been responsive to standard treatments.

METHODS

Fourteen patients (all female, of child-bearing age), who persistently failed traditional treatments, were treated with alitretinoin 10 mg/day for 24 weeks. The disease trend was evaluated by using both Sartorius and Dermatology Life Quality Index scores at time 0, at week 12 and at week 24.

RESULTS

A significant improvement was recorded in 78.5% of the cases.

CONCLUSION

Although more studies are necessary, this preliminary study shows that alitretinoin may have a role in the treatment of HS specifically in women of fertile age.

In-vivo data on the influence of tobacco smoke and UV light on murine skin

Inhaled tobacco smoke comes in direct contact with few organs such as mouth, lungs, and stomach. Cigarette smoke (CS) in lungs has been extensively studied. However, limited data exist on its effect on skin, and there are no long-term experimental studies suggesting toxic effects on skin. Even though it is generally accepted that CS is among the main factors of skin aging, the number of experimental studies showing this aging effect is limited. We hereby studied the effect of long-term exposure to CS on the skin of hairless mice in combination with or without ultraviolet (UV) light. In addition, we investigated potential skin protection by a potent antioxidant namely procyanidine-rich French maritime pine bark extract (PBE) pycnogenol. Male and female hairless SKH-2 mice were exposed for 10 months to tobacco smoke and/or UV light in vivo, and their effects on skin were investigated. Some biophysical parameters such as development of erythema, transepidermal water loss (TEWL), and skin elasticity were measured. The results show that UV and CS may be acting synergistically, as shown by the enhanced TEWL, erythema values, epitheliomas, and squamous cell carcinomas (SCCs) observed, whereas PBE seems to protect skin against SCC.