Otto H. Mills

Gram-negative folliculitis–a complication of antibiotic therapy in acne vulgaris

Fifty cases of Gram‐negative folliculitis have been identified amongst 1200 new cases of acne vulgaris in a period of 4 years. Two clinical varieties are recognized. Type I, the more common, presents as superficial pustules, usually grouped around the nose and is associated with a lactose fermenting Gram‐negative rod. Type II lesions are characterized by deep nodular and cystic lesions; Proteus appears to be the causative agent. The treatment of this condition is discussed.

Bacterial resistance and therapeutic outcome following three months of topical acne therapy with 2% erythromycin gel versus its vehicle.

Two-hundred-and-eight acne vulgaris patients were enrolled in a 24-week study to determine the bacterial resistance issues associated with the use of a topical 2% erythromycin gel. It consisted of a 12-week randomized, double-blind, parallel-group treatment phase comparing the active gel versus its vehicle followed by a 12-week single-blind regression phase with gel vehicle only. Bacteriological samples were taken from the face, back and nares for quantification by species and antibiotic resistance characteristics. Acne efficacy was assessed through week 12. The prevalence of erythromycin-resistant coagulase-negative Staphylococci on the face was extremely high (87%) at baseline, increased to 98% by week 12 in the erythromycin-treated group and did not change during regression. The density of these resistant organisms also significantly increased with erythromycin treatment with no change during regression. Similar prevalence and density patterns were also observed on the untreated back and in the nares. Nearly all of the resistant isolates were highly resistant (minimal inhibitory concentrations > 128 microg/ml). Resistance development was confined to the macrolide class of antibiotics. No anti-acne efficacy was observed.

Enhancement of comedogenic substances by ultraviolet radiation

Ultraviolet radiation enhanced the capacity of human sebum, sulphur, cocoa butter, squalene, and coal tar to produce comedones in the external ear canals of rabbits. An enhancement of the comedogenicity of coal tar and squalene was similarly demonstrated in man.

IS SULPHUR HELPFUL OH HARMFUL IN ACNE VULGARIS

Summary.— Suspensions and creams containing elemental sulphur were shown to be capable of inducing comedones in the rabbit ear and on human backs.Sulphur phur compounds, sulphides, sulphites, thiosulphates and thiols were inactive in this respect. Even though sulphur was not strongly comedogenic, the thesis is presented that its daily application in the treatment of acne vulgaris might perpetuate rather than ameliorate the disease. It is argued that sulphur has a dual paradoxical role in acne; it hastens the resolution of visible papulo‐pustules while insidiously promoting the formation of new comedones from which inflammatory lesions spring, thus establishing a vicious cycle.

A human model for assaying comedolytic substances

The comedolytic activity of topical medicaments may be quantitatively assessed by inducing microcomedones on the backs of black males by a 2‐week occlusive exposure to 10% crude coal tar. The test agents are then applied for 2 weeks and the reduction in density of microcomedones is determined by the non‐invasive ‘follicular biopsy’ technique using cyanoacrylate adhesive.

NAEVES COMEDONICUS TREATMENT WITH RETINOIC ACID

Summary.— Two patients are described with naevus comedonicus. Both patients were successfully treated with topical retinoic acid with a minimum of irritation. Continued periodic application of retinoic acid is necessary to prevent reaccumulation of horny material in the involved follicles.

Enhancement of delivery and bioavailability for drugs and cosmecueticals using amphoteric surfactants1

Biologically active ingredients designed for topical use on skin require optimum delivery to the epidermis and dermis in order to promote healthy skin. The desired efficacy is related to the formulation which is dependant upon mode of action and drug chemistry together with the dynamics involved in penetration and subsequent delivery and bioavailability within the epidermal and dermal layers. Amphoteric surfactants in particular are a class of agents which offer the formulator a vehicle to elicit rapid drug availability at the required site of action. Amphoterics are unique in that they can bealtered via formulation to behave as negativelt charged cationics which can carry anionic drugs such as retinoic acid into the skin , or they can be formulated as negatively charged anionic moieties and thus enhance the delivery of cationic active drugs. The foregoing examples suggest a delivery mechanism similar to high density lipoprotein transfer inherant in skin physiology. Thus simple amino acids and polypeptides together with amine functional sterols, all of which carry positive charges and/or can accept a proton are likely to form similar complex delivery systems.In addition, certain amphoterics which exhibit a pronounced isoelectric point where both positive and negative moieties in the molecule are balanced can be used as nonionic delivery enhancers for drugs which are charge sensitive. The versatility of these compounds as described above should receive considerable attentionfrom formulators and pharmacologists alike in providing more efficacious bioavailable drug delivery systems. They are in addition also well tolerated by both the eye and skin mucosa.