Preformulation study of the inclusion complex warfarin-beta-cyclodextrin.

Inclusion complex between warfarin and beta-cyclodextrin was obtained to improve the in vitro bioavailability of the drug in acidic media. Inclusion complexation in solution was studied by phase solubility technique. The apparent stability constant was influenced by the pH of the medium ranging from 633.26 M(-1) (at pH 1.2, where the drug was in unionised form) to 99.81 M(-1) (at pH 7.4, where the drug was in ionised form). Phase solubility study showed an AL-type diagram indicating the formation of an inclusion complex in 1:1 molar ratio. Solid binary mixtures of the drug with beta-cyclodextrin were prepared by several methods (physical mixing, kneading, co-evaporation, freeze-drying). Physicochemical characterizations were performed using differential scanning calorimetry, powder X-ray diffractometry and dissolution studies. Preparation method influenced the physicochemical properties of the binary mixtures. An inclusion complex was obtained by freeze-drying, and it showed a high solubility and drug dissolution rate. The physical stability of the complex was also studied. After one year storage in glass container at room temperature no significant changes were detected in the diffractogram, thermogram and dissolution profile of the freeze-dried product.

Oral 5-fluorouracil in squamous cell carcinoma of the skin in the aged.

Multiple or recurrent squamous cell skin carcinoma is a rare tumor in the aged. These patients are currently treated with 5-fluorouracil (5-FU) cream as a local chemotherapy; in cases in which the disease progresses, few treatments are available. Two reports deal with the treatment of progressive squamous cell skin carcinoma with systemic 5-FU, but in only eight patients age less than 70 years. We prospectively investigated oral 5-FU therapy in 14 consecutive patients (average age 76 1/2 years) with histologically proven squamous cell skin carcinoma. The disease was aggressive, multiple, or recurrent and had not been eradicated by surgery, radiation therapy, topical 5-FU cream, and non-5-FU chemotherapy. Oral 5-FU was administered as mannitol-coated 5-FU tablets at the daily dose of 175 mg/m2 for 3 weeks every 5 weeks. Toxicity, effectiveness, quality of life, and compliance to therapy were evaluated. Total cycles amounted to 55 (range: 2-6, mean: 4 for each patient) at an average dose intensity of 740 mg/m2/week for from 12 to 36 weeks. Only gastrointestinal toxicity World Health grade I occurred. Quality of life and compliance to therapy were 90%. Therapy induced measurable improvement in nine patients (64.3%): two partial remissions (14.3%), three minimal remissions (21.4%), and four arrests of disease (28.6%) with a median duration of 30+ months. The study ended because of a lack of patients. We can conclude that, if elderly patients require chemotherapy because of progressive multiple or advanced squamous cell skin carcinoma, appreciable results may be obtained with oral 5-FU as a single agent.