2.1

Material

Dexamethasone sodium phosphate (DSF) is used as the active ingredient. All of the substances that constituted the excipient of the preparations (cetaceum, white wax, liquid paraffin, borax) had a pharmaceutical quality.

2.2

Preparation of the formulation

The active preparation that consisted of DSF 1% in a water-in-oil (w/o) emulsion type cream excipient, and the placebo that did not contain an active ingredient and was only water in oil emulsion type cream were prepared using a hot preparation method in Ankara University, Faculty of Pharmacy, Department of Pharmaceutical Technology. The organoleptic controls of the preparations such as appearance, applicability and the ease of spread over the skin were done as well as the measurements for the viscosity. The viscosity measurements were performed using the Brookfield viscometer and spindle E, at a rotational speed of 5 rpm. The preparation that contained DSF and the placebo-water in oil emulsion type cream was prepared in 20 g tubes, and the DSF-containing one was labeled with a red and the placebo was labeled with a green label. The appearance, applicability and the ease of diffusion over the skin of the preparations were in the expected limits, and the viscosity was 766 ± 93.9 Pa · s.

2.3

Clinical study protocol

Patients were recruited from the Ministry of Health Ankara Research and Training Hospital, Ankara, Turkey, between January 2013 and August 2013. The study was conducted in accordance with the Declaration of Helsinki and this study protocol was approved by Ministry of Health, Ankara Research and Training Hospital Research Ethics Committee. Written informed consents were obtained from all patients prior to participation (ref. no: 0486/4041/26.12.2012).

This study was conducted as a prospective, double-blind, placebo-controlled study.

The study group consisted of 32 females admitted to the otorhinolaryngology outpatient clinic with the complaint of ear itching, and the control group consisted of 42 females who admitted with other complaints. There were no patients who dropped out of the study.The patients with any systemic disease (diabetes mellitus, hepatic and renal diseases, lymphoma, leukemia or other malignancies), atopic dermatitis, a perforated tympanic membrane and middle ear disorders were excluded. The patients who had any medical treatment for their external ear canal disease in the previous month were also excluded.

On the admission of the patients to outpatient clinic, a detailed otorhinolaryngologic examination was performed. Visual analog scale (VAS) for evaluation of self-reported itching scores between 0 and 10 point is recorded (0 = no itching at all, 10 = sleep disturbance due to itching). The duration of itching, any treatments received, use of cotton tips for ear picking, the habit of ear washing or a long exposure time to water were questioned. Patients with an active external ear canal infection were excluded. Patients were informed about avoiding excessive ear cleaning and aural irrigation during the treatment period.

The patients were asked to use the red-labeled preparation containing 1% dexamethasone sodium in their right and the green labeled placebo-water in oil emulsion cream in their left ears, twice a day. Both the patient and physicians were blinded to the type of preparation used for each side. They applied a thin layer of the preparations into their external ear canals with the help of a cotton bud. This application was performed for 15 days, and then the medication was stopped at the end of the 15th day. All patients successfully completed the treatment.

The patients were subjectively evaluated using VAS. The moisture, pH and sebum levels of their external ear canals were measured by pharmaceutical technology. The pretreatment and post-treatment measurements (moisture, pH, and sebum) of the study group were compared with the ones of the control group. In addition, 15th and 30th day moisture, pH and sebum levels of active treatment ears (right ears) and placebo ears (left ears) were compared with the baseline levels and the levels of the control group. Pretreatment and post-treatment itching VAS scores were also compared.

2.4

Measurements of sebum, pH and moisture levels of the external ear canal skin

The amount of sebum, moisture content, and pH changes in the ear canal skin was measured using Sebumeter, Corneometer and pH-meter combined in one device (Sebumeter SM 810/Corneometer CM 825/skin-pH-meter PH 900, Cutometer dual MPA 580, Courage and Khazaka Electronic GmbH, Cologne, Germany) which is allowing to measuring with noninvasive methods. These measurements were carried out by Ankara University Faculty of Pharmacy, Department of Pharmaceutical Technology.

The sebum level of the ear skin was determined with Sebumeter SM 810. Sebum was collected with a special opaque plastic tape (64 mm ² ) by pressing onto the skin for 30 s with a slight pressure. The resulting increase in transparency of the tape was measured and the displayed values tally to the sebum amount of the skin surface in μg sebum/cm ² .

The skin surface pH of the external ear canal was measured with a Skin-pH-Meter PH 900 with a flat glass electrode and a precision of 0.1 pH-unit. The resulting pH value is displayed after 3 s.

Measurements of the external ear canal skin hydration were performed with a Corneometer CM 825. The measuring principle of the Corneometer CM 825 is based on the capacitance measurement of a dielectric medium. Any change in the dielectric constant due to skin surface hydration variation alters the capacitance of a precision measuring capacitor. The capacitance is expressed digitally in arbitrary units (a.u.)

2.5

Statistical analysis

The analysis of the data was performed using SPSS for Windows 11.5 package program. The normality of the distribution was analyzed with Kolmogorov–Smirnov test for continuous and discrete numeric variables. The descriptive statistics are shown as mean ± standard deviation or median (minimum − maximum) for continuous and discrete numeric variables, and as number and percent for categorical variables.

The difference between the groups for the mean ages was analyzed using Student’s t test, and the differences for the medians were studied with Mann–Whitney U test. Friedman test was used to analyze statistically significant differences at different time points in the study group. Wilcoxon sign test was used in order to detect the time points that caused the difference after a significant result is obtained with the Friedman test. p < 0.05 was regarded as statistically significant. However, a Bonferroni correction was performed in all multiple comparisons in order to control for type I error.

2.1

Material

Dexamethasone sodium phosphate (DSF) is used as the active ingredient. All of the substances that constituted the excipient of the preparations (cetaceum, white wax, liquid paraffin, borax) had a pharmaceutical quality.

2.2

Preparation of the formulation

The active preparation that consisted of DSF 1% in a water-in-oil (w/o) emulsion type cream excipient, and the placebo that did not contain an active ingredient and was only water in oil emulsion type cream were prepared using a hot preparation method in Ankara University, Faculty of Pharmacy, Department of Pharmaceutical Technology. The organoleptic controls of the preparations such as appearance, applicability and the ease of spread over the skin were done as well as the measurements for the viscosity. The viscosity measurements were performed using the Brookfield viscometer and spindle E, at a rotational speed of 5 rpm. The preparation that contained DSF and the placebo-water in oil emulsion type cream was prepared in 20 g tubes, and the DSF-containing one was labeled with a red and the placebo was labeled with a green label. The appearance, applicability and the ease of diffusion over the skin of the preparations were in the expected limits, and the viscosity was 766 ± 93.9 Pa · s.

2.3

Clinical study protocol

Patients were recruited from the Ministry of Health Ankara Research and Training Hospital, Ankara, Turkey, between January 2013 and August 2013. The study was conducted in accordance with the Declaration of Helsinki and this study protocol was approved by Ministry of Health, Ankara Research and Training Hospital Research Ethics Committee. Written informed consents were obtained from all patients prior to participation (ref. no: 0486/4041/26.12.2012).

This study was conducted as a prospective, double-blind, placebo-controlled study.

The study group consisted of 32 females admitted to the otorhinolaryngology outpatient clinic with the complaint of ear itching, and the control group consisted of 42 females who admitted with other complaints. There were no patients who dropped out of the study.The patients with any systemic disease (diabetes mellitus, hepatic and renal diseases, lymphoma, leukemia or other malignancies), atopic dermatitis, a perforated tympanic membrane and middle ear disorders were excluded. The patients who had any medical treatment for their external ear canal disease in the previous month were also excluded.

On the admission of the patients to outpatient clinic, a detailed otorhinolaryngologic examination was performed. Visual analog scale (VAS) for evaluation of self-reported itching scores between 0 and 10 point is recorded (0 = no itching at all, 10 = sleep disturbance due to itching). The duration of itching, any treatments received, use of cotton tips for ear picking, the habit of ear washing or a long exposure time to water were questioned. Patients with an active external ear canal infection were excluded. Patients were informed about avoiding excessive ear cleaning and aural irrigation during the treatment period.

The patients were asked to use the red-labeled preparation containing 1% dexamethasone sodium in their right and the green labeled placebo-water in oil emulsion cream in their left ears, twice a day. Both the patient and physicians were blinded to the type of preparation used for each side. They applied a thin layer of the preparations into their external ear canals with the help of a cotton bud. This application was performed for 15 days, and then the medication was stopped at the end of the 15th day. All patients successfully completed the treatment.

The patients were subjectively evaluated using VAS. The moisture, pH and sebum levels of their external ear canals were measured by pharmaceutical technology. The pretreatment and post-treatment measurements (moisture, pH, and sebum) of the study group were compared with the ones of the control group. In addition, 15th and 30th day moisture, pH and sebum levels of active treatment ears (right ears) and placebo ears (left ears) were compared with the baseline levels and the levels of the control group. Pretreatment and post-treatment itching VAS scores were also compared.

2.4

Measurements of sebum, pH and moisture levels of the external ear canal skin

The amount of sebum, moisture content, and pH changes in the ear canal skin was measured using Sebumeter, Corneometer and pH-meter combined in one device (Sebumeter SM 810/Corneometer CM 825/skin-pH-meter PH 900, Cutometer dual MPA 580, Courage and Khazaka Electronic GmbH, Cologne, Germany) which is allowing to measuring with noninvasive methods. These measurements were carried out by Ankara University Faculty of Pharmacy, Department of Pharmaceutical Technology.

The sebum level of the ear skin was determined with Sebumeter SM 810. Sebum was collected with a special opaque plastic tape (64 mm ² ) by pressing onto the skin for 30 s with a slight pressure. The resulting increase in transparency of the tape was measured and the displayed values tally to the sebum amount of the skin surface in μg sebum/cm ² .

The skin surface pH of the external ear canal was measured with a Skin-pH-Meter PH 900 with a flat glass electrode and a precision of 0.1 pH-unit. The resulting pH value is displayed after 3 s.

Measurements of the external ear canal skin hydration were performed with a Corneometer CM 825. The measuring principle of the Corneometer CM 825 is based on the capacitance measurement of a dielectric medium. Any change in the dielectric constant due to skin surface hydration variation alters the capacitance of a precision measuring capacitor. The capacitance is expressed digitally in arbitrary units (a.u.)

2.5

Statistical analysis

The analysis of the data was performed using SPSS for Windows 11.5 package program. The normality of the distribution was analyzed with Kolmogorov–Smirnov test for continuous and discrete numeric variables. The descriptive statistics are shown as mean ± standard deviation or median (minimum − maximum) for continuous and discrete numeric variables, and as number and percent for categorical variables.

The difference between the groups for the mean ages was analyzed using Student’s t test, and the differences for the medians were studied with Mann–Whitney U test. Friedman test was used to analyze statistically significant differences at different time points in the study group. Wilcoxon sign test was used in order to detect the time points that caused the difference after a significant result is obtained with the Friedman test. p < 0.05 was regarded as statistically significant. However, a Bonferroni correction was performed in all multiple comparisons in order to control for type I error.