A study of the clinical activity of a gel combining monocaprin and doxycycline: a novel treatment for herpes labialis.

BACKGROUND: Current treatment of herpes labialis is usually with topical antiviral drugs and early drug administration is required for effectiveness. Monocaprin, a 1-monoglyceride of capric acid, has high microbicidal activity in vitro and efficiently inactivates herpes simplex virus. Tetracyclines are inhibitors of matrix metalloproteinases that are part of the inflammatory response and contribute to the breakdown of tissue in ulcers. The study objective was to investigate the antiviral and wound-healing effect of a hydrogel containing either monocaprin or a combination of monocaprin and a low dose of doxycycline in vivo against herpes labialis. METHODS: Subjects were divided into two groups: (i) with prodromal symptoms of herpes labialis; (ii) with a vesicle. Both groups applied the hydrogel five times a day for five days. Test formulations were: (i) hydrogel containing monocaprin and doxycycline (MCD), (ii) hydrogel containing only monocaprin and (iii) placebo hydrogel. Formulations were distributed randomly to subjects within each group. Subjects recorded treatment results in a 6-day diary and a 7-day follow-up diary. RESULTS: For the MCD group the mean time to healing was 5.5 days (prodromal) and 5.3 days (vesicles/ulceration) or significantly shorter than for the placebo groups (7.25 and 7.5 days respectively; P < 0.05). Pain relief was significantly more with MCD (combining both the prodromal and vesicle groups) than with the monocaprin and placebo groups (P = 0.0114). CONCLUSION: Combining monocaprin with low-dose doxycycline offers an effective treatment for herpes labialiss, significantly reducing time to healing and pain compared with the placebo and monocaprin alone.

Stable concentrated emulsions of the 1-monoglyceride of capric acid (monocaprin) with microbicidal activities against the food-borne bacteria Campylobacter jejuni, Salmonella spp., and Escherichia coli.

Of 11 fatty acids and monoglycerides tested against Campylobacter jejuni, the 1-monoglyceride of capric acid (monocaprin) was the most active in killing the bacterium. Various monocaprin-in-water emulsions were prepared which were stable after storage at room temperature for many months and which retained their microbicidal activity. A procedure was developed to manufacture up to 500 ml of 200 mM preconcentrated emulsions of monocaprin in tap water. The concentrates were clear and remained stable for at least 12 months. They were active against C. jejuni upon 160- to 200-fold dilution in tap water and caused a >6- to 7-log(10) reduction in viable bacterial count in 1 min at room temperature. The addition of 0.8% Tween 40 to the concentrates as an emulsifying agent did not change the microbicidal activity. Emulsions of monocaprin killed a variety of Campylobacter isolates from humans and poultry and also killed strains of Campylobacter coli and Campylobacter lari, indicating a broad anticampylobacter activity. Emulsions of 1.25 mM monocaprin in citrate-lactate buffer at pH 4 to 5 caused a >6- to 7-log(10) reduction in viable bacterial counts of Salmonella spp. and Escherichia coli in 10 min. C. jejuni was also more susceptible to monocaprin emulsions at low pH. The addition of 5 and 10 mM monocaprin emulsions to Campylobacter-spiked chicken feed significantly reduced the bacterial contamination. These results are discussed in view of the possible utilization of monocaprin emulsions in controlling the spread of food-borne bacteria from poultry to humans.

Antimicrobial activity of monocaprin: a monoglyceride with potential use as a denture disinfectant.

Monocaprin is a 1-monoglyceride of capric acid that has antimicrobial activity against enveloped viruses, certain bacteria, and the yeast Candida albicans. Solutions containing monocaprin were formulated and tested in vitro against a number of micro-organisms, including species found in the oral cavity and common pathogenic species. The antimicrobial activity of monocaprin was tested with strains growing on a surface as well as in the planktonic phase. Micro-organisms tested were: Streptococcus mutans, Candida albicans, Lactobacillus sp., Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. Two sets of dilutions were prepared for each test strain; one to be inoculated with the micro-organism growing in the planktonic phase and the other with the same strain growing on a filter paper disk. Control solutions were also prepared to find out if any of the excipients were affecting the microbicidal effect of monocaprin. Test strains growing on the filter paper surface were less sensitive to monocaprin than the same strain growing in its planktonic phase. C. albicans was the micro-organism that was most sensitive to monocaprin, but S. mutans also showed appreciable sensitivity. The indication that monocaprin may have potential as a topical agent against Candida was tested in an open study of denture disinfection in 32 patients attending a geriatric daycare centre. A significant, but short-term, reduction in counts of Candida on the fitting surface of full dentures was observed.