This is a multicenter, open-label study to assess systemic plasma levels of calcitriol, calcium homeostasis and safety in adults with plaque-type psoriasis under conditions of maximized use of CD 2027 3µg/g oily spray twice daily (6 g daily), applied to 20% of BSA for 3 weeks.

There are a total of six visits: Pre-treatment period (Day -15, Day -8 and Day -1) and Treatment period (Day 1/ Baseline, Day 15 and Day 22).

Inclusion Criteria:

• Diagnosis of plaque-type psoriasis involving 10% - 20% of body surface area (BSA), with a Global Severity Score of at least 3 (moderate)

Exclusion Criteria:

• Other type of psoriasis (other than plaque)
• Significant abnormal lab findings
• Secondary hyperparathyroidism
• Vit D deficiency
• Hypercalcemia