The Role of Platelet Homeostasis in a Novel Topical PRP Formulation.

BACKGROUND: Topical platelet-rich plasma (PRP) must demonstrate stability to insure biologic activity in aesthetic medicine. OBJECTIVE: The objective of this research was to evaluate the role of platelet homeostasis in a novel PRP topical cosmetic formulation to provide facial appearance improvement. METHODS: The stability of the topical PRP formulation was evaluated in vitro followed by clinical in vivo testing. The in vitro evaluation examined platelet stability and morphology over a 90-day period within the preservative cosmetic base utilizing ELISA and light microscopy (LM)/scanning electron microscopy (SEM). The in vivo clinical study enrolled 20 subjects in a 120-day double blind split face study to evaluate the effect of 5–7x concentrated PRP compared to 2–3x concentrated PRP on facial photoaging. Cosmetic effect was evaluated by the subject and the dermatologist investigator on a 5-point ordinal scale at baseline, week 8, and week 16. RESULTS: 90-day stability for the topical PRP formulation was verified via ELISA and LM/SEM. ELISA showed the PRP was more inactive than control conditions via analyte concentration curves (PDGF-AB, EGF, and P-Selectin). LM/SEM demonstrated the PRP had less aggregation/activation over time within the cosmetic base and that refrigeration is superior to room-temperature storage thus delaying full platelet degranulation. The in vivo clinical study demonstrated parity between 20ml and 60ml PRP in terms of clinical efficacy. CONCLUSION: Platelets remain viable for up to 90 days in a refrigerated cosmetic vehicle with demonstrated topical clinical PRP facial benefits. PRP kits of 20ml and 60ml volumes for topical PRP are equally efficacious. J Drugs Dermatol. 2020;19(12): doi:10.36849/JDD.2020.5495.

Ayurvedic formulations containing benzoic and ascorbic acids as additives: benzene formation during storage and impact of additives on quality parameters.

OBJECTIVES: Ayurvedic formulations are becoming the prior choice of people as health care supplements. The increasing demand for these formulations has led to extensive development of Ayurvedic pharmaceutical industries worldwide. The reaction between the preservatives (sodium benzoates and ascorbic acid) used in these formulations could generate benzene. Benzene is classified as class-1 human carcinogen and responsible for various short and long term health effects. METHODS: In this study, 25 formulations (containing ascorbic acid and sodium benzoate) of various manufacturers available as over the counter products were obtained and their benzene content were determined using gas chromatograph with flame ionization detector. RESULTS: The result showed that 64% of the formulations were free from benzene contamination whereas 36% of formulations were found to be contaminated with benzene. A simple, less time-consuming, economic, and validated gas chromatographic method for estimation of benzene in Ayurvedic formulations was also developed successfully in present study. CONCLUSIONS: The data revealed that the level of benzene was within permissible limits, yet the presence of a carcinogen in the marketed formulations intended for internal use is an alarming situation.

Phycocosmetics and Other Marine Cosmetics, Specific Cosmetics Formulated Using Marine Resources.

Marine resources exist in vast numbers and show enormous diversity. As a result, there are likely many possible applications for marine molecules of interest in the cosmetic industry, whether as excipients or additives, but especially as active substances. It is possible to obtain extracts from active substances; for example, quite a few algae species can be used in moisturizing or anti-ageing products. In the field of topical photoprotection, mycosporine-like amino acids and gadusol are important lines of enquiry that should not be overlooked. In the field of additives, the demonstration that certain seaweed (algae) extracts have antimicrobial properties suggests that they could provide alternatives to currently authorized preservatives. These promising leads must be explored, but it should be kept in mind that it is a long process to bring ingredients to market that are both effective and safe to use.

Distribution of benzalkonium chloride into the aqueous phases of submicron dispersed systems: emulsions, aqueous lecithin dispersion and nanospheres.

Partitioning of benzalkonium chloride (BAC) into the aqueous phases of submicron dispersed systems such as submicron emulsions, aqueous lecithin dispersion (WLD), and suspension of nanospheres (NLC) was studied. The aqueous phases of the investigated systems were obtained by ultracentrifugation and subsequently were subjected to ultrafiltration, which procedure allowed distinguishing between the fractions of free benzalkonium chloride (w) and those incorporated in the liposomal and micellar region (wlm). The fractions present in the oily phase and in the interphase of submicron emulsions were calculated. Despite the various composition of the investigated formulations and the initial concentration of BAC, w values were very small at 0.2-8.0%. The wlm value in submicron emulsions was increased by increasing the total concentration of preservative from 29.0 to 42.0%. Using polysorbate 80 instead of lecithin resulted in a distribution of BAC to aqueous-liposomal-micellar phase that was twice as high. The very low concentration of antimicrobial active form of benzalkonium chloride was analyzed in the aqueous phase of emulsions stabilized with lecithin as well as in aqueous lecithin dispersion and nanospheres (below 3%). Replacement of lecithin with polysorbate 80 in emulsions with polysorbate significantly increase (up to 8%) the fraction of benzalkonium chloride in the aqueous phase where microbial growth occurs.

Preservative effect of Chinese cabbage (Brassica rapa subsp. pekinensis) extract on their molecular docking, antioxidant and antimicrobial properties.

This study aimed at investigating the antimicrobial activity of different solvent extracts of Chinese cabbage Brassica rapa subsp. pekinensis (BRARP) and their antioxidant and cytotoxicity properties. Of the different solvents extracts, the chloroform extracts (CE) were significantly inhibited the bacterial pathogens at minimum inhibitory concentration (MIC) of 16.5 mg.mL-1. Biochemical analysis revealed that total phenol (62.6 ± 0.05 mg GAE.g-1) and flavonoids (27.6 ± 0.04 mg QE.g-1) were higher in the extracts of BRARP, which resulted in enhanced antioxidant activity in CE. A total of eight dominant compounds were detected in the potent antimicrobial extract from BRARP based on GC-MS analysis. The molecular interactions study revealed that, among the screened compounds the 1,2-benzenedicarboxylic acid and 2,3-dicyanopropionamide interacted with the active site of pathogenicity and survival related protein with lipopolysaccharide (LpxC) with higer binding energy. This work concluded that the 1, 2-Benzenedicarboxylic acid and 2, 3-Dicyanopropionamide from BRARP was reported to be good non-cytotoxic and antioxidant antimicrobials against bacterial pathogens.

Lippia origanoides essential oil: an efficient and safe alternative to preserve food, cosmetic and pharmaceutical products.

AIMS: The aim of this work was to evaluate the efficacy and safety of Lippia origanoides essential oil as a preservative in industrial products. METHODS AND RESULTS: The composition, antimicrobial activity, mutagenic and toxic potential of L. origanoides were determined. Then, the effect of essential oil as a preservative in food, cosmetics and pharmaceutical products was evaluated. The essential oil of L. origanoides consisted mainly of oxygenated monoterpenes (38·13%); 26·28% corresponded to the compound carvacrol. At concentrations ranging from 0·312 to 1·25 µl ml-1 and in association with polysorbate 80, the essential oil of L. origanoides inhibited the growth of all the tested micro-organisms. The medium lethal dose in mice was 3·5 g kg-1 , which categorizes it as nontoxic according to the European Union criteria, and negative results in the Ames test indicated that this oil was not mutagenic. In combination with polysorbate 80, the essential oil exerted preservative action on orange juice, cosmetic and pharmaceutical compositions, especially in the case of aqueous-based products. CONCLUSIONS: Lippia origanoides essential oil is an effective and safe preservative for orange juice, pharmaceutical and cosmetic products. SIGNIFICANCE AND IMPACT OF THE STUDY: This study allowed for the complete understanding of the antimicrobial action and toxicological potential of L. origanoides essential oil. These results facilitate the development of a preservative system based on L. origanoides essential oil.

Thinned stone fruits are a source of polyphenols and antioxidant compounds.

BACKGROUND: Thinned fruits are agricultural by-products that contain large quantities of interesting compounds due to their early maturity stage. In this work, the phenolic profile and the antioxidant activity of six thinned stone fruits (apricot, cherry, flat peach, peach, plum and nectarine) have been investigated, focussing on proanthocyanidins. RESULTS: Thinned nectarine had the highest content of total phenols [67.43 mg gallic acid equivalents (GAE) g-1 dry weight (DW)] and total flavonoids (56.97 mg CE g-1 DW) as well as the highest antioxidant activity measured by DPPH scavenging (133.30 mg [Trolox equivalents (TE) g-1 DW] and FRAP assay (30.42 mg TE g-1 DW). Proanthocyanidins were very abundant in these by-products, and the main phenolic group quantified in cherry (10.54 mg g-1 DW), flat peach (33.47 mg g-1 DW) and nectarine (59.89 mg g-1 DW), while hydroxycinnamic acids predominate in apricot, peach and plum (6.67, 22.04 and 23.75 mg g-1 DW, respectively). The low, mean degree of polymerisation of proanthocyanidins suggests that their bioavailability could be very high. CONCLUSIONS: This study shows that thinned stone fruit extracts might be used as antioxidants in foods or as a source of compounds with health-related benefits that can be used in the pharmaceutical, cosmetic and food industries. © 2016 Society of Chemical Industry.

Stability of (-)-epigallocatechin gallate and its activity in liquid formulations and delivery systems.

(-)-Epigallocatechin gallate (EGCG) has become a popular disease-preventive supplement worldwide because it may aid in slowing down the onset of age-related diseases such as cancer, diabetes and tissue degeneration. As largely demonstrated in cell culture studies, EGCG possesses antioxidant properties and exhibits favorable effects on gene expression, signal transduction and other cell functions. However, only limited effects have been observed in experimental animals and human epidemiological studies. The inconsistency between the biological activity of EGCG in cell cultures and in vivo can be attributed to its low stability, which not only decreases its bioavailability but also leads to the formation of degradation products and prooxidant molecules with possible side-effects. Understanding EGCG degradation kinetics in solution and in vivo is crucial for its successful clinical application. Ambient conditions (pH, temperature, oxygen) can either enhance or decrease the stability of EGCG, thus influencing its biological activity. Usage of stabilizers and/or encapsulation of EGCG into particulate systems such as nanoparticles or microparticles can significantly increase its stability. In this review, the effects of ambient conditions, stabilizers and encapsulation systems on EGCG stability, activity and degradation rate are illustrated.

Preparation and in vitro/in vivo evaluation of antimicrobial ocular in situ gels containing a disappearing preservative for topical treatment of bacterial conjunctivitis.

The study aimed to formulate and evaluate levofloxacin hemihydrate ocular in situ gels along with freshly prepared disappearing preservative reported to be safer to human eyes. Formulae were prepared using thermosensitive (PF127 and PF68) or ion-activated (Gelrite) polymers. They were evaluated for gelation temperature (GT), capacity, content uniformity, pH, rheological behavior, in vitro drug release with kinetic analysis. Best formulae were exposed to storage effect to select the optimum formula that was subjected to different sterilization methods and in vivo evaluation. The prepared disappearing preservative (sodium perborate monohydrate) proved to be active oxidative preservative and compatible with our formulae. F9 (24% PF127, 15% PF 68, 0.5% levofloxacin hemihydrate, and 0.0025% sodium perborate monohydrate) showed prolonged drug release (12 h), acceptable GT, viscosity, and pH. It remained stable over 3 months at two temperatures and was best sterilized by filtration. It showed longer residence time (12 h) in rabbits' eye fluids compared with the Levoxin® eye drops (4 h). This successful attempt of using thermo-gelling system along with a disappearing type of preservatives would allow the use of these systems to achieve sustained release of antimicrobial drugs with minimum risk of eye damage improving patient compliance and treatment efficacy.

Toxicological evaluation of isopropylparaben and isobutylparaben mixture in Sprague-Dawley rats following 28 days of dermal exposure.

The alkyl esters of p-hydroxybenzoic acid (Parabens) have been of concern due to their probable endocrine disrupting property especially in baby consumer products. The safety of parabens for use as a preservative in cosmetics has come into controversy, and thus consumer demand for paraben-free products is ever increasing. Thus, more comprehensive studies are needed to conclusively determine the safety of the multiple prolonged exposure to parabens with cosmetic ingredients. This study was conducted to investigate the potential repeated 28 days dermal toxicity (50, 100, 300, or 600 mg/kg bw/day) of isopropylparaben (IPP), isobutylparaben (IBP), or the mixture of IPP and IBP in rats. There were no significant changes in body and organ weights in any group. However, histopathological examinations showed that weak or moderate skin damages were observed in female rats by macroscopic and microscopic evaluations. In female rats, no observed adverse effect levels (NOAELs) of IPP with no skin lesion and IBP for skin hyperkeratosis, were estimated to be 600 mg/kg bw/day, and 50 mg/kg bw/day, respectively. With regard skin hyperkeratosis, the lowest observed adverse effect level (LOAEL) of the mixture of IPP and IBP was estimated to be 50 mg/kg bw/day. Analysis of six serum hormones (estrogen, testosterone, insulin, T3, TSH, or FSH) in animals showed that only FSH was dose-dependently decreased in the mixture groups of 100 mg/kg bw/day or higher. These data suggest that the mixture of IPP and IBP showed a synergistic dermal toxicity in rats and should be considered for future use in consumer products.

An in vitro study to determine the effect of Terminalia chebula extract and its formulation on Streptococcus mutans.

AIM: Many weapons are available in the arsenal of a dental professional to combat dental caries, which is almost ubiquitously present. From a public health perspective, most of these weapons are far from being an ideal drug. Hence, there is a demand for better and effective antibacterial agents. This factor stimulated the process of the present study. The aim of the study was to determine the effect of ethanol extract of Terminalia chebula on Streptococcus mutans. MATERIALS AND METHODS: Dried ripe fruits of Terminalia chebula were procured and powdered. Physical tests were done to estimate purity of the fruit powder. Hydroethanolic and aqueous extracts were prepared according to standard procedures. Minimum inhibitory concentration of the extracts was determined by tube dilution method and confirmed by agar dilution method. The effect of the hydroethanolic extract on sucrose induced adhesion, glucan-induced aggregation and on glycolysis of Streptococcus mutans was also assessed. Preservative, gelling agent and sweetener were added in suitable quantities to the ethanol extract, and mouthrinse was formulated. Minimum inhibitory concentration of the formulation was also determined. RESULTS: Yield was better in case of aqueous extract. The Minimum inhibitory concentration of hydroethanolic extract was determined to be 2.5%. Minimum inhibitory concentration of the aqueous extract was determined to be 10%. Hydroethanolic extract of Terminalia chebula (2.5%) inhibited sucrose induced adherence and aggregation of Streptococcus mutans in vitro. CONCLUSION: The mouthrinse formulated from ethanol extract of Terminalia chebula demonstrated substantial antibacterial activity and could be used as an effective anticaries agent. CLINICAL SIGNIFICANCE: Terminalia chebula mouthrinse can be effectively used in clinical practice as an anticaries mouthrinse with additional benefit being that it is safe and economical.

Retention of polyphenolic species in spray-dried blackberry extract using mannitol as a thermoprotectant.

The purpose of these studies was to determine if a Büchi Mini Spray Dryer B-290 (Büchi Corporation, New Castle, DE, USA) could be used to prepare blackberry extract powders containing mannitol as a thermoprotectant without extensively degrading anthocyanins and polyphenols in the resulting powders. Three blackberry puree extract samples were each prepared by sonication of puree in 30/70% ethanol/water containing 0.003% HCl. Blackberry puree extract sample 1 (S1) contained no mannitol, while blackberry puree extract sample 2 (S2) contained 3.0:1 (w/w) mannitol:berry extract, and blackberry puree extract sample 3 (S3) contained 6.3:1 (w/w) mannitol:berry extract. The levels of anthocyanins and polyphenols in reconstituted spray-dried powders produced from S1-S3 were compared to solutions of S1-S3 that were held at 4°C as controls. All extract samples could be spray-dried using the Büchi Mini Spray Dryer B-290. S1, with no mannitol, showed a 30.8% decrease in anthocyanins and a 24.1% decrease in polyphenols following spray-drying. However, S2 had a reduction in anthocyanins of only 13.8%, while polyphenols were reduced by only 6.1%. S3, with a ratio of mannitol to berry extract of 6.3:1, exhibited a 12.5% decrease in anthocyanins while the decrease in polyphenols after spray-drying was not statistically significant (P=.16). Collectively, these data indicate that a Büchi Mini Spray Dryer B-290 is a suitable platform for producing stable berry extract powders, and that mannitol is a suitable thermoprotectant that facilitates retention of thermosensitive polyphenolic species in berry extracts during spray-drying.

[Optimization the formulation of Eisemia foetida protein burn spray by response surface methodology].

OBJECTIVE: To optimize the formulation of Eisemia foetida protein (EFP) burn spray. METHODS: A five-factor, three-level response surface method was employed; The response variable was the proliferation effect of EFP on NIH3T3 cells. RESULTS: The optimization formulation was as follows: the proportion of EFP, glycerol and mannitol was 0.91%, 1.42% and 5%, respectively; 0.02 mol/L Na2 HPO4 and 0.01 mol/L citric acid buffer system corresponding pH value was 7.0. CONCLUSION: The response surface method is reliable, efficient and suitable for optimizing the formulation of EFP burn spray.

Solid lipid nanoparticles as effective reservoir systems for long-term preservation of multidose formulations.

Cosmetic multidose preparations, as well as pharmaceutical ones, are at risk of contamination by microorganisms, due to their high water content. Besides the risk of contamination during manufacturing, multidose cosmetic preparations may be contaminated by consumers during their use. In this paper, the results of the utilization of nanoparticles as reservoir systems of parabens, the most used class of preservatives, were reported. Two different systems, solid lipid nanoparticles (SLN) made of pure precirol and nanostructured lipid carriers (NLC) made of precirol and almond oil, containing three parabens as single molecules or as a mixture, were prepared and tested. All the systems were characterized for size, polydispersion index, zeta potential and encapsulation efficiency. Release experiments, carried out in steady state and sink conditions, allowed to evidence that both SLN and NLC were able to act as reservoir systems. The antimicrobial activity of the systems was tested against Candida albicans ATCC 10231 with repeat insult tests. The results of the release experiments and the antimicrobial tests showed very low water concentration of parabens still maintaining their antimicrobial activity.

Influence of trace elements on stabilization of aqueous solutions of ascorbic acid.

Together with vitamin C, zinc, selenium, manganese, and magnesium play a vital role in the preservation of organs scheduled for transplantation. In the present study, it is shown that addition of 1 mg/l of these elements influences the stability of 0.3 mM ascorbic acid solutions. The solution's stability was estimated using an accelerated stability test. The concentration of vitamin C was measured using a validated spectrophotometric method, which uses the reduction of 2,6-dichlorophenoloindophenol by ascorbic acid. Elevated temperatures, the factor accelerating substances' decomposition reaction rate, were used in the tests. The research was conducted at two temperatures at intervals of 10 °C: 80 ± 0.1 and 90 ± 0.1 °C. It was stated that the studied substances' decomposition occurred in accordance with the equation for first-order reactions. The function of the logarithmic concentration (log%C) over time was revealed to be rectilinear. This dependence was used to determine the kinetics of decomposition reaction rate parameters. The stabilization of vitamin C solutions was measured as the time in which 10 % of the substance decomposed at 20 and 0 °C. Addition of Se(IV) or Mg(II) ions significantly increase the stability of ascorbic acid solution (∼34 and ∼16 %, respectively), but Zn(II) causes a significant decrease in stability by ∼23 %. Addition of Mn(II) has no significant influence on vitamin C stability.

The constituents of essential oil: antimicrobial and antioxidant activity of Micromeria congesta Boiss. & Hausskn. ex Boiss. from East Anatolia.

The chemical composition, antimicrobial activity, total phenol content, total antioxidant activity, and total oxidant status of the essential oil from Micromeria congesta Boiss. & Hausskn. ex Boiss. were investigated. Steam distillation was used to obtain the essential oil, and the chemical analyses were performed by gas chromatography-mass spectrometry. The antimicrobial activity was tested by an agar disc diffusion method against the tested microorganisms: Bacillus subtilis NRRL B-744, Bacillus cereus NRRL B-3711, Staphylococcus aureus ATCC 12598, S. aureus ATCC 25923, S. aureus ATCC 25933, Escherichia coli 0157H7, E. coli ATCC25922, Micrococcus luteus NRLL B-4375, Enterococcus faecalis ATCC 19433, Proteus vulgaris RSKK 96026, and Yersinia enterecolitica RSKK 1501. The major compounds found in volatiles of M. congesta were piperitone oxide, linalool oxide, veratrole, pulegone, dihydro carvone, naphthalene, iso-menthone, para-menthone, and cyclohexanone. Compared to that of reference antibiotics, the antibacterial activity of the essential oil is considered as significant. Results showed that M. congesta has the potential for being used in food and medicine depending on its antioxidant and antibacterial activity.

Formulation and evaluation of in situ gelling systems for intranasal administration of gastrodin.

Gastrodin is the major bioactive constituent of the traditional Chinese drug "Tianma." It is used in the treatment of some nervous system diseases and can be transported to the brain via intranasal administration. In the current paper, the development of a novel ion-activated in situ gelling system for the nasal delivery of gastrodin is discussed. An in situ perfusion model was used to determine the absorption-rate constant of gastrodin through rat nasal mucosa. The optimal formulation was determined by measuring the critical cation concentration, anti-dilution capacity, gel expansion coefficient, water-holding capacity, and adhesive capacity. The best formulation consisted of 10% gastrodin, 0.5% deacetylated gellan gum as the gelatinizer, and 0.03% ethylparaben as the preservative. The rheological properties of gastrodin nasal in situ gels were also investigated. The viscosity and elasticity sharply increased at temperatures below 25°C. When physiological concentrations of cations were added into the preparation, the mixture gelled into a semi-solid. The results of an accelerated stability test show that gastrodin nasal in situ gels can be stable for more than 2 years. Mucociliary toxicity was evaluated using the in situ toad palate model and the rat nasal mucociliary method; both models demonstrated no measurable ciliotoxicity. Pharmacodynamic studies suggest that similar acesodyne and sedative effects were induced following intranasal administration of 50 mg/kg gastrodin nasal in situ gels or oral administration of 100 mg/kg gastrodin solution. The in situ gel preparation is a safe and effective nasal delivery system for gastrodin.

Rubus rosaefolius extract as a natural preservative candidate in topical formulations.

Even though the synthetic preservatives may offer a high antimicrobial efficacy, they are commonly related to adverse reactions and regarded as having potentially harmful effects caused by chronic consumption. The development of natural preservatives provides a way of reducing the amount of synthetic preservatives normally used in pharmaceutical and cosmetic preparations. In addition, these agents have less toxic effects and represent a possible natural and safer alternative of the preservatives. The purpose of this research was to evaluate the Rubus rosaefolius Smith extract efficiency as a natural preservative in base formulations. Of the extract, 0.2% (w/w) was assayed for its effectiveness of antimicrobial protection in two different base formulations (emulsion and gel). The microbial challenge test was performed following the standard procedures proposed by The United States Pharmacopoeia 33nd, European Pharmacopoeia 6th, Japanese Pharmacopoeia 15th, and the Cosmetics, Toiletries, and Fragrance Association using standardized microorganisms. The results demonstrated that R. rosaefolius extract at the studied concentration reduced the bacterial inocula, satisfying the criterion in all formulations, even though it was not able to present an effective preservative behavior against fungi. Thus, the investigation of new natural substances with preservative properties that could be applied in pharmaceutical and cosmetic products is relevant due to the possibility of substituting or decreasing the concentration of synthetic preservatives, providing a way for the development of safer formulas for the use of consumers.

A successful virtual screening application: prediction of anticonvulsant activity in MES test of widely used pharmaceutical and food preservatives methylparaben and propylparaben.

A discriminant function based on topological descriptors was derived from a training set composed by anticonvulsants of clinical use or in clinical phase of development and compounds with other therapeutic uses. This model was internally and externally validated and applied in the virtual screening of chemical compounds from the Merck Index 13th. Methylparaben (Nipagin), a preservative widely used in food, cosmetics and pharmaceutics, was signaled as active by the discriminant function and tested in mice in the Maximal Electroshock (MES) test (i.p. administration), according to the NIH Program for Anticonvulsant Drug Development. Based on the results of Methylparaben, Propylparaben (Nipasol), another preservative usually used in association with the former, was also tested. Both methyl and propylparaben were found active in mice at doses of 30, 100, and 300 mg/kg. The discovery of the anticonvulsant activities in the MES test of methylparaben and propylparaben might be useful for the development of new anticonvulsant medications, specially considering the well-known toxicological profile of these drugs.

The mucosal toxicity of different benzalkonium chloride analogues evaluated with an alternative test using slugs.

PURPOSE: The objective of this study was to evaluate the mucosal toxicity of different benzalkonium chloride (BAC) analogues using slugs as the alternative test organism. METHODS: The effect of different BAC analogues on the mucosal tissue of slugs was determined from the protein, lactate dehydrogenase, and alkaline phosphatase released from the foot mucosa after treatment. Additionally, mucus production and reduction in body weight of the slugs were measured. The eye irritation potency of the molecules was evaluated with the Bovine Corneal Opacity and Permeability (BCOP) assay. The antimicrobial activity of the different BAC analogues was also assessed. RESULTS: All BAC analogues induced severe damage to the mucosal epithelium of the slugs, and the irritation increased with decreasing alkyl chain length: BAC-C16 < BAC-C14 < BAC-C12 approximately BAC-mix. A similar ranking was obtained with the BCOP assay for eye irritation. The relative order of activities among the three BAC analogues was the same, i.e., BAC-C14 > or = BAC-C16 > BAC-C12. The BAC-C14 exhibited higher activity than the BAC-mix. CONCLUSIONS: The toxicity and activity of BAC analogues depend on the alkyl chain length. The use of BAC-C14 as a conservative agent in pharmaceutical preparations instead of the BAC-mix should be considered.