Stability of prostaglandin E compounds in solution

Preparation, characterization, and stability of new prostaglandin E2 gel for local administration

A new gel delivery system for the local application of prostaglandin E2 consists of drug incorporated in the matrix of a cross-linked starch polymer. The properties of the starch powder provide a stabilizing milieu for the labile prostaglandin E2 and, by addition of saline, a ready-to-use gel for immediate local administration. The gel offers advantages over existing preparations in terms of chemical and microbiological stability, homogeneity, and dosage safety. This report outlines the pharmaceutical aspects involved in the development of the delivery system.

Stage-dependent reduction in T colony formation in Hodgkin's disease. Coincidence with monocyte synthesis of prostaglandins

Prostaglandin synthesis and T lymphocyte colony formation have been examined in previously untreated patients with Hodgkin's disease. Mononuclear cells have been isolated from peripheral blood and spleens of these patients. Significant augmentation in prostaglandin E levels were noted in the mononuclear cell cutures from Hodgkin's disease patients compared with controls (1.64 +/- 0.29 vs. 0.39 +/- 0.09 ng/10(6) cells, P < 0.005). Measured prostaglandin E levels increased with advancing stage of disease. Virtually all of the prostaglandins were synthesized by the adherent monocyte cell population. Prostaglandin E was the major product. Clonal expansion of a T lymphocyte precursor cell, which gives rise to colonies > 50 cells, was determined by a layered soft agar method. T colony formation was significantly reduced in patients with stage II, III, and IV disease. There were progressively reduced colony numbers seen with advancing stage of disease (609 +/- 209, 416 +/- 158, 207 +/- 58 compared with normals 2,274 +/- 360 colonies/10(6) cells plated; P < 0.005). The addition of inhibitors of endogenous prostaglandin synthesis resulted in significant augmentation of T colony number. However, a consistent relative decrease in T colony number was seen even when endogenous prostaglandin E synthesis was blocked. It would appear that both the prostaglandin-dependent and independent T colony precursor cells are lost with progressive stage of disease. A causative role of augmented prostaglandin synthesis in this stage-dependent reduction of T colony formation could not be established.

Synthesis of prostaglandins in platelets of hypercholesterolemic rabbits

As a continuation of previous studies on the synthesis of prostaglandins in platelets of human venous blood, the present communication describes the synthesis of prostaglandins in experimental hypercholesterolemia induced in rabbits by dietary means. In such a condition, high serum level of cholesterol did not change the rate of prostaglandin synthesis.