Efficacy and Safety of TC Cream In Treating Patients With Psoriasis Vulgaris

Inclusion Criteria:

- Age of 18-70 years old. Both men and women and members of all races and ethnic groups

- Consistent with diagnostic criteria of stable phase psoriasis vulgaris and have at
least two target lesions suitable for evaluation

- Women of childbearing age must be using birth control strategies defined by one of the
following: 1) a barrier method (condom) and/or 2) oral contraceptives, during the
8-week study period.

- ISGA score ≥ 2 (at least mild severity)

- BSA (stable stage group): 1%≤ to ≤20%

- Signed a written informed consent document

- No additional exposure to the sun

Exclusion Criteria:

- Subjects in pregnancy, preparing for pregnancy or breast feeding

- History of hyperergic or photosensitivity

- History of complicated cardiovascular diseases, cerebrovascular diseases, severe
primary diseases of hepatic, kidney and hematopoietic system, or patients with
psychiatric disorders

- History of photosensitive diseases such as porphyria, chronic actinic dermatitis,
Xeroderma pigmentosa

- Within 4 weeks prior to randomizations, patients have taken treatment with following
approved or investigational psoriasis therapies on the target lesions:

- Topical treatments

- PUVA, UVB or Grenz ray therapy.

- Any systemic treatments other than biologicals with a possible effect on
psoriasis (e.g., corticosteroids, vitamin D analogues, hydroxycarbamide,
azathioprine, methotrexate, cyclosporine, other immunosuppressant).

- Any types of other investigational therapies for psoriasis

- Within 3 months prior to randomizations, patients have taken systemic treatments with
retinoids or biological therapies (marketed or otherwise) with a possible effect on
psoriasis (e.g., alefacept, efalizumab, etanercept, infliximab).

- Planned initiation of, or changes to, concomitant medications that could affect
psoriasis (e.g., beta blockers, anti-malaria drugs, lithium) during the double-blind
phase of the study.

- History of allergic reactions attributed to compounds of similar chemical or biologic
compositions to Coumarins.