INTRODUCTION
Psoriasis is a common chronic inflammatory skin disease which affects 2-3 % of the European population.1 Psoriasis vulgaris (chronic plaque psoriasis) is the most frequent form of psoriasis which is characterized by high degree of epidermal proliferation and damaged keratinocyte differentiation leading to thickened, scaly, and itchy skin plaques.2 Blood vessels in the affected skin areas get dilated and are infiltrated by inflammatory cells which further triggers the pathophysiological processes of psoriasis.3 Psoriatic infiltrate consists of variety of infiltrating cells that are distributed in the epidermis and upper dermis of the diseased skin and its analysis forms an important step in understanding the pathogenesis and therapeutics in psoriasis.4
Management of psoriasis includes regulation of epidermal proliferation and reduction of inflammatory reactions.5 There are several topical treatments available, including corticoids and vitamin-D derivates.6 Calcipotriol (vitamin D3-analogue) has been known to possess cutaneous safety and efficacy against psoriasis vulgaris in extensive, well-controlled clinical studies.7,8 Calcipotriol was well tolerated in these studies, with only mild adverse events which later diminished on continuation of the treatment. The monotherapy with calcipotriol cream was reported to be as efficient as the topical corticosteroid betamethasone.9 In recent years, treatment of topical agents under occlusive dressings has become a popular method of screening new drugs. A clinical study conducted on psoriasis vulgaris reported that the therapeutic response to calcipotriol increased with hydrocolloid occlusive dressing due to enhanced penetration.10 Relatively shorter study duration (2 weeks or less) used under occlusive treatment is known to provide a better insight into novel compounds and their formulations, offering quick decisions in early phase of clinical development.11,12 Shorter application duration also offers better standardization of protocol and a reduced cost of clinical trial.
Non-adherence to topical treatment has been identified as an important issue in the management of psoriasis and is likely to affect the treatment outcome.13 New formulation and drug delivery systems may help to improve compliance and can increase the choices for the patient to find a product with acceptable properties.14 An innovative dosage form, based on water-free lipid formulation system (AKVANO®, Lipidor AB, Danderyd, Sweden) for topical administration has been developed.15,16 The active ingredients are dissolved in a volatile
Management of psoriasis includes regulation of epidermal proliferation and reduction of inflammatory reactions.5 There are several topical treatments available, including corticoids and vitamin-D derivates.6 Calcipotriol (vitamin D3-analogue) has been known to possess cutaneous safety and efficacy against psoriasis vulgaris in extensive, well-controlled clinical studies.7,8 Calcipotriol was well tolerated in these studies, with only mild adverse events which later diminished on continuation of the treatment. The monotherapy with calcipotriol cream was reported to be as efficient as the topical corticosteroid betamethasone.9 In recent years, treatment of topical agents under occlusive dressings has become a popular method of screening new drugs. A clinical study conducted on psoriasis vulgaris reported that the therapeutic response to calcipotriol increased with hydrocolloid occlusive dressing due to enhanced penetration.10 Relatively shorter study duration (2 weeks or less) used under occlusive treatment is known to provide a better insight into novel compounds and their formulations, offering quick decisions in early phase of clinical development.11,12 Shorter application duration also offers better standardization of protocol and a reduced cost of clinical trial.
Non-adherence to topical treatment has been identified as an important issue in the management of psoriasis and is likely to affect the treatment outcome.13 New formulation and drug delivery systems may help to improve compliance and can increase the choices for the patient to find a product with acceptable properties.14 An innovative dosage form, based on water-free lipid formulation system (AKVANO®, Lipidor AB, Danderyd, Sweden) for topical administration has been developed.15,16 The active ingredients are dissolved in a volatile
