L. A. Ahlstrom

Barazone decreases skin lesions and pruritus and increases quality of life in dogs with atopic dermatitis: a randomized, blinded, placebo-controlled trial

A randomized, blinded, placebo-controlled study was conducted to assess the efficacy of a new 0.025% budesonide leave-on-conditioner (Barazone) in controlling the clinical signs of canine atopic dermatitis (AD). Twenty-nine dogs with AD were randomly allocated to receive 3 weeks of once-weekly treatment with either Barazone or Placebo and then were crossed-over to receive the alternative treatment for a further 3 weeks. At the start and end of each treatment phase, referring veterinarians performed a dermatological and general physical examination on each dog, assigned a Lesional Score, collected blood for haematological and biochemical analyses and rated the dogs overall tolerance to the preceding treatment. Owners assessed their dogs level of pruritus and quality of life (QoL) daily, using visual analogue scales labelled with behavioural descriptors. Barazone improved skin lesions (P = 0.02) and QoL (P < 0.001) and reduced pruritus (P ≤ 0.002) compared with treatment with Placebo. There were no significant differences in the tolerance scores and only minor differences in the general physical examination findings and haematological and biochemical parameters between dogs receiving Barazone or Placebo. This study demonstrated that Barazone, applied once weekly at 1 g/kg for 3 weeks, was an efficacious treatment for the control of the clinical signs of AD in dogs.

The effects of formulation on the penetration and retention of budesonide in canine skin in vitro.

This study investigated the effects of formulation on the penetration and retention kinetics of budesonide through canine skin in vitro. Full thickness, thoracic, dog skin was mounted in Franz-type diffusion cells and randomly assigned to receive one of three 0.025% (0.25mg/mL) budesonide-containing formulations: Barazone (BZ, a novel formulation), isopropyl myristate (IPM) or propylene glycol (PG). At regular intervals over 84h, the amount of budesonide penetrating or retained within the skin was quantified using high performance liquid chromatography. The restricted (or residual) maximum likelihood mixed model predicted that the flux of budesonide from BZ was 9.2-fold (P<0.001) and 105-fold (P<0.001) greater than from IPM and PG, respectively. Similarly, the skin retention of budesonide from BZ was more than 3-fold (P<0.0001) and nearly 6-fold (P<0.0001) greater than from IPM and PG, respectively. This study has demonstrated that the formulation can greatly affect the skin penetration and retention of budesonide in dogs, and consequently could be selected to maximise drug concentration and retention at the site of action. This has the potential to improve the efficacy and safety of, and owner compliance with, topical glucocorticoid therapy in dogs.

The effects of surface preparation on the penetration of hydrocortisone through canine skin.

This study investigated the effects of common skin surface preparations on the penetration kinetics of hydrocortisone through canine skin. Thoracic skin from five dogs was clipped of hair, divided between five treatment groups and prepared as follows: shaved (S); tape-stripped with adhesive bandage (TS); cleaned with aqueous chlorhexidine (Aq-C); cleaned with alcoholic chlorhexidine (Al-C); or allocated to the control group and had no further preparation performed (C). The skin samples were mounted in Franz-type diffusion cells and transdermal hydrocortisone penetration was measured over 30h. The pseudo-steady-state flux (J(SS)) of hydrocortisone through S, Al-C, Aq-C and TS skin was, respectively, 2.3 (P=0.021), 2.2 (P=0.037), 2.0 (P=0.070) and 1.5 (P=0.351) times greater than through the control skin, but there were no significant differences in the lag times (t(lag)) for hydrocortisone penetration between the groups. The study has shown that some skin surface preparations can significantly increase the subsequent penetration of hydrocortisone through canine skin in vitro.

The effects of skin disease on the penetration kinetics of hydrocortisone through canine skin in vitro

This study investigated the effects of allergic skin disease on the penetration kinetics of hydrocortisone through canine skin in vitro. Full-thickness lesional and nonlesional (normal) skin was removed from the dorsal lumbosacral and dorsocaudal thoracic regions, respectively, of five canine cadavers. The dogs were suspected of having flea allergy dermatitis based on their distribution and types of skin lesions. Nonlesional skin was confirmed to be histologically normal, and the histopathology of the lesional skin was consistent with allergic dermatitis. Excised skin was clipped, mounted in Franz-type diffusion cells, and the transdermal penetration of a saturated, radiolabelled hydrocortisone solution was measured over 30 h. When the penetration data for all five dogs were pooled, a restricted (or residual) maximal likelihood mixed model predicted that the permeability coefficient and pseudosteady-state flux of hydrocortisone was more than twice as great (95% confidence interval 1.55-2.71 times as great; P < 0.0001) through lesional compared with nonlesional skin. There was no significant difference in the lag time for hydrocortisone penetration through lesional compared with nonlesional skin of the dogs. This study has confirmed that the transdermal penetration of hydrocortisone may be altered, typically increased twofold, but could be as high as 10-fold, through lesional compared with nonlesional skin of dogs with suspected flea allergy dermatitis. This is likely to be affected by variables such as disease severity, concurrent infections and interindividual differences in skin characteristics.