Psoriasis Case Study

1. INTRODUCTION
1.1 Psoriasis1-5 :-
The prevalence of the psoriasis in India is found to be 8%.The male to female ratio in Psoriasis was 1.1:1.[1]
Psoriasis is chronic, inflammatory, noncontiguous, genetic disease of immune system that affect to skin or joint. In which there are sharply defined red patches on the skin, covered by a silvery, flaky surface observed.
Mainly the process starts in the basal (deepest) layer of the epidermis, where keratinocytes are made. Keratinocytes are immature skin cells. They produce keratin that is tough protein that helps form hair, nails and skin. In normal cell growth, keratinocytes grow normally and moves up from the bottom layer to the skin's surface and shed unnoticed. This process takes nearly a month.

It is affected by various factor like secretion from glands, content and amount of secretion etc., affect the drug transport through this route. This route consist only 0.1% of total skin surface. ii) Transcellular route :-
Drug transport through this route passes from corneocytes which has highly hydrated keratin making hydrophilic pathway. This corneocytes are surrounded by lipid connecting these cells. So a drug requires a number of partitioning and diffusion step. In this route drug passes through cytoplasm of cells. This route is suitable for hydrophilic drugs and highly hydrated keratin gives aqueous pathway to the hydrophilic drugs. The drug passes through the corneocytes of stratum corneum. iii) Intercellular route :-
Intercellular pathway the drug diffuses through the continuous lipid matrix present between the cells. The barrier of this route is due tortuous structure formed by corneocytes and the drug has to pass through the alternating aqueous domain and lipid by partitioning into the lipid bilayer and diffusing to the inner side of the skin. The water molecules have been travel 50 times more by this route so. It is suitable mainly for uncharged lipophilic