No abstract

Dithranol is infrequently used in psoriasis in spite of excellent efficacy due to its local adverse effects. We have synthesized a novel formulation of dithranol in which the drug is entrapped in phospholipid liposomes. This formulation has shown markedly low irritation and minimal staining of skin and clothes in preliminary studies. Twenty patients with bilaterally symmetrical stable plaque psoriasis applied 0.5% dithranol lipogel to lesions over one side of the body. On the other side, 10 patients were randomized to apply pure liposomal base and 10 applied a conventional cream containing 1.15% dithranol, 1.15% salicylic acid and 5.3% coal tar in a 30-minute, short contact regimen for 6 weeks. Patients were assessed for disease severity, perilesional erythema and skin staining, pruritus and any other adverse effects at baseline, 2, 4 and 6 weeks. Both lipogel and the cream significantly reduced the total severity score compared to the liposomal base at 4 (p = 0.004) and 6 (p = 0.01) weeks. There was no significant difference in the clinical response of dithranol cream and lipogel. Markedly low incidence and severity of perilesional erythema (p<0.001) and skin staining (p<0.05) was seen with the lipogel in comparison with the cream.

We have prepared a novel, aqueous gel-based, liposome-entrapped formulation of dithranol. Herein, we report preliminary observations on its efficacy, tolerability, and cosmetic acceptability in treating stable plaque psoriasis. Nineteen plaques of psoriasis in nine adult patients were treated for six weeks in a prospective, open-label trial. In five patients, there was total clearance of lesions, with more than 50% subsidence in a further two patients. Significantly, there were no reports of lesional or perilesional irritation, and only one patient showed faint brown staining of the skin, which was completely and rapidly reversible. These preliminary results indicate that our liposomal dithranol gel has potential advantages over presently available preparations of dithranol; these may translate into enhanced acceptance of this useful drug by patients and physicians.

High-potency adsorbates of chloroquine phosphate (CQP) were prepared by the batch method using a polyacrylic acid ion-exchange resin. Taste evaluation of the adsorbates shows significant masking of the bitterness of the drug. The complex formation was complete at pH 6.0. Stability studies at 37 degrees C, 45 degrees C, and 60 degrees C indicated that the complex was stable at all conditions for 1 month. In vitro release studies revealed complete drug elution from the complex at pH 1.2 and 2.0.

The aim of the present study was to encage a drug into liposomal structures to make them more effective, safe and targeted to liver cells. The investigation deals with critical parameters controlling the formulation and evaluation of silibinin (silymarin, CAS22888-70-6) liposomes. Small unilamellar liposmal vesicles were prepared using the ethanol injection method. The various formulation and process variables were optimized to improve the drug entrapment efficiency. The study includes the selection of lipid composition, impact of charge imparting agent and the nature of hydration medium. The stability and size parameters were critically monitored. The liposomal systems were also studied for hepatoprotective activity in mice against carbon tetrachloride induced hepatotoxicity and gastroprotective activity using the pyloric ligation method. The results indicate a significant effect of cholesterol on drug-entrapment and drug-leakage characteristics. The size distribution range was from 0.056-1.270 microns with the most frequent size ranging from 0.266-0.466 micron. The amount of drug loaded in these vesicles was approx. 90%. Lipid cholesterol mass ratio of 10:2 has a maximum entrapment of 87.2% (+/- 1.77). The results obtained from the in vivo studies indicate the improved performance of silymarin in liposomes at a level of 55.6% hepatoprotection in comparison to 33.08% of plain drug. Plain liposomes showed hepatoprotection though to a lower degree of 24.2%. Liposomal silymarin and plain liposomes also showed significant antiulcer activity as compared with plain silymarin and control groups.