title: Comparison of various pharmaceutical preparations of prednicarbate after repeated topical administration to the skin of rats.
abstract: The following pharmaceutical preparations of prednicarbate (Hoe 777) were tested: fatty ointment 0.1% and 0.25%, ointment 0.1% and 0.25%, cream 0.1% and 0.25%, solution 0.25%. These pharmaceutical preparations were applied 10 times to the shorn back of male Sprague-Dawley rats. After sacrifice the following parameters were recorded: body weight, skin thickness as well as ultimate load, ultimate strain, tensile strength and modulus of elasticity of excised skin strips. Soluble fractions of collagen (soluble in 0.15 and 0.5 molar NaCl solution and in citrate buffer) and insoluble collagen as well as total collagen/g fresh weight were determined. The values of the treated animals were compared with the values of untreated animals and animals treated with the individual base only. As found in earlier studies prednicarbate induced a slight decrease of body weight and skin thickness. Ultimate extension and ultimate load were only barely changed. There was, however, a dose-dependent increase of modulus of elasticity and tensile strength, due to treatment with prednicarbate. Simultaneously, an increase on insoluble collagen and of total collagen per g fresh weight was noted. These results confirm previous findings, indicating a positive correlation between tensile strength and modulus of elasticity of connective tissue with the content of insoluble collagen. The effects of ointment, fatty ointment and cream are very similar, nevertheless, they depend on the type of formulation applied. In the case of prednicarbate solution the dependence of the effects upon the formulation used is very obvious. The increase of tensile strength and modulus of elasticity as well as of insoluble collagen show that very impressively.
mesh_terms: D000287:Administration, Topical; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D004548:Elasticity; D004655:Emulsions; D008297:Male; D009824:Ointments; D011239:Prednisolone / Q000008:administration & dosage / Q000031:analogs & derivatives*; D051381:Rats; D011919:Rats, Inbred Strains; D012867:Skin / Q000187:drug effects*; D012996:Solutions; D013718:Tensile Strength
chemical_list: D004655:Emulsions; D009824:Ointments; D012996:Solutions; D011239:Prednisolone; C035287:prednicarbate