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Biomedical subjects

O H Mills

Publications and source records attributed to O H Mills.

At least 19 recordsLinked to original sources
PubMed1998

Irritation potential of a new topical tretinoin formulation and a commercially-available tretinoin formulation as measured by patch testing in human subjects.

BACKGROUND: A novel tretinoin preparation uses polyolprepolymer-2, a compound designed to reduce skin irritation by helping retain drugs on and in the surface layers of the skin. OBJECTIVE: We used patch testing to measure the effect of polyolprepolymer-2 on tretinoin-associated irritation. METHODS: Two patch test studies were conducted. The first assessed the effect of polyolprepolymer-2 by comparing commercially-available tretinoin formulations with respective polyolprepolymer-containing formulations of 0.025% tretinoin gel and 0.025%, 0.05%, and 0.1% tretinoin creams. The second assessed the effect of the polyolprepolymer-2 concentration on the potential decrease in irritation by comparing: (1) a commercially-available tretinoin cream with prototype tretinoin creams containing 20% polyolprepolymer-2 at three different concentrations of tretinoin (0.025%, 0.05%, and 0.1%); and (2) the effect of three different polyolprepolymer-2 concentrations (10%, 15%, and 20%) in prototype tretinoin creams on cumulative irritation. Patch agents were assigned to subjects according to a randomization schedule, and during a period of 5 days each subject received three 24-hour exposures to the test materials. Twenty-four hours elapsed between old patch removal and new patch application. RESULTS: In the first study, the tretinoin gel and cream containing polyolprepolymer-2 caused significantly less irritation than all equivalent formulations of the commercially-available tretinoin gel and creams except the 0.025% cream formulation. Irritation scores were not significantly different in terms of irritation in the 0.025% creams although scores did indicate a trend towards lower irritation with 0.025% tretinoin cream containing polyolprepolymer-2. In the second study, the tretinoin gel containing polyolprepolymer-2 and the three tretinoin prototype creams also containing polyolprepolymer-2 caused significantly less irritation than comparable concentrations of the commercially-available tretinoin. In addition, the 0.025% tretinoin gel formulation containing polyolprepolymer-2 was no more irritating than the commercially-available 0.025% tretinoin cream. CONCLUSION: Tretinoin formulations containing polyolprepolymer-2 are, in general, less irritating than the currently marketed tretinoin formulations.

Administration, Topical↗
PubMed1998

Adapalene 0.1% gel for the treatment of acne vulgaris: its superiority compared to tretinoin 0.025% cream in skin tolerance and patient preference.

One hundred patients with acne vulgaris applied adapalene (Differin) 0.1% gel to one side of their face and tretinoin 0.025% cream to the other once a day for 4 weeks; the side of application was determined by randomization code. Patient tolerance (assessed as the side of the face least irritated by drug application) was recorded weekly and patient preference (assessed as the preparation more easily spread, absorbed more quickly, smelled better, felt best on the skin and least greasy to the feel) at completion of the study. The investigator measured skin irritation weekly, scoring erythema, skin dryness, desquamation and burning/stinging on a 10-point scale. After each week of treatment, 64-68% of patients found adapalene 0.1% gel more tolerable than tretinoin 0.025% cream (P < 0.05). At study completion, 65% of patients preferred adapalene 0.1% gel over tretinoin 0.025% cream (P = 0.003). An overall assessment showed adapalene 0.1% gel was significantly less irritating to the skin in terms of producing erythema, dryness, desquamation and burning/stinging, at Visits 2, 3 and 4 (P < 0.02). Thirty-two patients experienced mild to moderately severe adverse events; three had adverse events considered to be drug related (two with skin discomfort; one with skin dryness). One patient stopped using the study drugs because of dry skin. This study showed that a majority of patients preferred adapalene 0.1% gel over tretinoin 0.025% cream and that it caused significantly less skin irritation.

Acne Vulgaris↗
PubMed1998

Comparison of adapalene 0.1% solution and tretinoin 0.025% gel in the topical treatment of acne vulgaris.

A multicentre study was conducted to compare clinical safety and efficacy of adapalene 0.1% solution and tretinoin 0.025% gel, both topical treatments for acne, in a once-daily dosage regimen for 12 weeks. A total of 297 patients were enrolled by eight investigators in this randomized, investigator-masked study in a parallel group design. An open label period using adapalene followed this study to assess the long-term safety of adapalene solution. Adapalene and tretinoin proved to be clinically and statistically effective in treating acne by reducing inflammatory (47% and 50%, respectively) and non-inflammatory lesions (57% and 54%) as compared to baseline. When comparing patients who had 75% or greater improvement in open comedones, adapalene was shown to be significantly more effective than tretinoin. No serious adverse event was reported during this study, including during the long-term period. The reactions that occurred were similar between treatments, i.e. burning, pruritus, scaling, dryness and erythema.

Acne Vulgaris↗
PubMed1993

Noninvasive assessment of anesthetic activity of topical lidocaine formulations.

The effectiveness of a series of lidocaine formulations in producing anesthesia after topical application was evaluated in human volunteers. The formulations, five suspensions in 20% propylene glycol and one cream, were applied to the forearms for 3 h with occlusion with Hilltop chambers. Testing for anesthesia was performed electrometrically. All lidocaine-containing formulations produced significantly greater anesthesia than the blanks. The formulation containing tetradecyltrimethylammonium bromide produced greater anesthesia than that containing octadecyltrimethylammonium chloride. Changing the pH of the formulation from 7.9 to 10.0 had no significant effect. Other formulations (sodium lauryl sulfate and the cream) were no more effective than the plain formulation without surfactants. The rank order for the suspension formulations was the same as for steady-state permeation in in vitro experiments. However, application of the cream formulation produced greater effect in vivo than was anticipated from in vitro flux values.

Administration, Topical↗
PubMed1991

Defining the susceptibility of acne-prone and sensitive skin populations to extrinsic factors.

Acne-Prone Skin. Acne-prone skin appears to be more susceptible to certain extrinsic factors that can either exacerbate existing disease or generate new lesions. Awareness of the factors that could worsen or interfere with therapy is important. In addition, identification of patients with minimal acne who are prone to outbreaks from extrinsic factors and provision of relevant advice could prove beneficial to significant numbers of patients. Sensitive Skin. From the perspective of our research, the definition of sensitive skin is still evolving. Certain individuals may view sensitive skin as fashionable; however, clinicians and the people who work in the personal-care industry know that when certain materials are applied to the skin, some individuals report symptoms (burning, stinging, itching, a tight feeling) and sometimes show traditional signs of irritation. The reasons for sensitive skin in these individuals may be obvious, but many times the complaints and signs of irritation occur in individuals who appear to be normal. Using our ongoing work we would like to suggest that the label "sensitive skin" apply to the following four categories: 1. Those individuals with obvious skin disease. 2. Those individuals with subclinical (mild) or atypical clinical signs of disease. 3. Those individuals who have experienced past insults to the skin. 4. Those individuals who do not fit into one of the above three categories and appear to be "normal". To define sensitive skin fully we may need to perform full profiles of the skin of these patients. In addition to history and examination, a battery of noninvasive tests may be helpful.(ABSTRACT TRUNCATED AT 250 WORDS)

Acne Vulgaris↗
PubMed1988

A comparative study of benzoyl peroxide and clindamycin phosphate for treating acne vulgaris.

A water based 5% benzoyl peroxide gel (Benzac W5) was compared with topical 1% clindamycin phosphate solution (Cleocin T) in the treatment of acne vulgaris using a randomized, investigator blind study design. Lesion counts were significantly reduced in both treatment groups over the 12-week study period; however, the reduction of total lesions produced by benzoyl peroxide gel was significantly greater than that produced by clindamycin phosphate (P less than 0.05). Clindamycin phosphate had a milder effect on the skin surface in terms of peeling and drying than the benzoyl peroxide gel.

Acne Vulgaris↗
PubMed1987

Effects of sulfur and salicylic acid in a shampoo base in the treatment of dandruff: a double-blind study using corneocyte counts and clinical grading.

The effectiveness of sulfur 2 percent and salicylic acid 2 percent either alone or in combination in a shampoo base was determined in a double-blind controlled study using two methods of evaluation: clinical assessment of scaling and corneocyte counts (the number of desquamating cells/cm2). Forty-eight subjects (twenty-nine men and nineteen women) with moderate to severe scaling shampooed their hair under supervision twice a week for five weeks, using one of four formulas: sulfur 2 percent plus salicylic acid 2 percent in a shampoo vehicle; sulfur 2 percent in a shampoo vehicle; salicylic acid 2 percent in a shampoo vehicle; or the shampoo vehicle alone. On days 0, 7, 14, 21, 28, and 35 the degree of scaling was assessed, and specimens were taken for corneocyte counts. Significantly greater and earlier reductions in both degree of scaling and corneocyte counts were seen in subjects treated with the formula containing both sulfur 2 percent and salicylic acid 2 percent in the shampoo base than in those who received either active ingredient alone or the shampoo vehicle.

Adult↗
PubMed1986

Comparing 2.5%, 5%, and 10% benzoyl peroxide on inflammatory acne vulgaris.

A 2.5% formulation of benzoyl peroxide was compared with its vehicle, and with a 5% and a 10% proprietary benzoyl peroxide gel preparation in three double-blind studies involving 153 patients with mild to moderately severe acne vulgaris. The 2.5% benzoyl peroxide formulation was more effective than its vehicle and equivalent to the 5% and 10% concentrations in reducing the number of inflammatory lesions (papules and pustules). Desquamation, erythema, and symptoms of burning with the 2.5% gel were less frequent than with the 10% preparation but equivalent to the 5% gel. The 2.5% formulation also significantly reduced Propionibacterium acnes and the percentage of free fatty acids in the surface lipids after 2 weeks of topical application.

Acne Vulgaris↗
PubMed1983

Propionibacterium acnes resistance to antibiotics in acne patients.

The minimal inhibitory concentration (MIC) of Propionibacterium acnes in seventy-five acne patients receiving long-term antibiotic therapy demonstrated the emergence of resistant strains. The mean MIC in thirty-three patients receiving long-term tetracycline was four to five times higher than that found in control groups of acne patients not receiving antibiotic therapy and controls free of acne. The average MIC for erythromycin was more than 100 times higher in those receiving long-term antibiotic therapy. In a second group of sixty-two patients, the clinical course and number of P. acnes were correlated with the presence of "resistant strains" defined as P. acnes with a tenfold increase in MIC to tetracycline or erythromycin. Patients with resistant strains had higher counts of P. acnes and clinically were not doing as well as those with sensitive strains.

Acne Vulgaris↗
PubMed1983

The follicular biopsy.

The 'follicular biopsy' is an extension of the noninvasive 'surface biopsy' technique originated by Dawber and Marks. A quick-setting cyanoacrylate polymer is used to extract the contents of sebaceous follicles. The retrieved material can be examined histologically at the light or electron microscopic level. Many types of analyses may be performed; microbial density, lipid components (acne), mite population (Demodex), hair retention (trichostasis), penetration of topical drugs and chemicals, localization of enzymes, etc. The follicular biopsy is useful for studying the contents of sebaceous follicles in health and disease.

Acne Vulgaris↗
PubMed1983

Assay of comedolytic activity in acne patients.

Comedolytic activity was assessed in acne patients by determining the reduction in facial microcomedones using the cyanoacrylate follicular biopsy technique. Microcomedones were counted in five-em squares after 8 to 12 weeks of treatment. Only salicylic acid and tretinoin among seven conventional anti-acne medications were found to possess comedolytic activity. The latter was the more effective.

Acne Vulgaris↗
PubMed1982

Comedogenicity of sunscreens. Experimental observations in rabbits.

Fourteen of 29 proprietary sunscreen formulations, including suntan promoters, were found to be comedogenic when applied to the external ear canal of albino rabbits. Ultraviolet exposures enhanced the comedogenic effect. The vehicles, rather than the UV-absorbing compounds, seemed to be responsible. accordingly, sunscreen acne may be a subtype of acne cosmetica. A sampling of UV absorbers showed these agents to be noncomedogenic.

Acne Vulgaris↗
PubMed1982

A human model for assessing comedogenic substances.

Substances that are moderately to strongly comedogenic in the rabbit ear model test have been found to be capable of inducing comedones in the human model described in this report. The test substances are applied under occlusion for one month to the upper part of the backs of young adult, black men who have large follicles. The degree of follicular hyperkeratosis is assessed by a noninvasive "follicular biopsy" techniques, employing a fast-setting cyanoacrylate glue to remove the follicular contents. The rabbit model is more sensitive than the human. Substances that are weakly comedogenic in the rabbit are probably safe for human use with the possible exception of acne-prone persons.

Animals↗
PubMed1981

Oral vitamin A in acne vulgaris. Preliminary report.

Oral vitamin A (retinol) is generally not considered useful in the treatment of acne vulgaris. We conducted a study which showed that retinol was indeed ineffective at the usual doses of 50,000 to 100,000 IU daily. Retinol was highly efficacious in doses of 300,000 units for women and 400,000 to 500,000 units for men, toxicity was slight and limited mainly to skin (xerosis) and mucous membranes (cheilitis). The danger of hypervitaminosis A in this dosage range has been exaggerated. Retinol is a valuable drug for treating stubborn, severely inflammatory acne vulgaris. It is administered until the disease is brought under control, usually within three to four months. Then the dosage is progressively reduced relying on conventional drugs to keep the disease in abeyance.

Acne Vulgaris↗