[The stability of all-trans retinoic acid in "retinoid solutions" of "Di Bella's Cure"]. / Stabilità dell'acido all-trans retinoico nella "soluzione ai retinoidi" della "cura Di Bella".

Recently all-trans retinoic acid, an oxidation product of retinol, has become famous, since it is a component of "retinoids solution" of "Di Bella's therapy". Since all-trans retinoic acid is rapidly destroyed in the presence of light and oxidants, we verified its stability in samples of "retinoids solution" stored in conditions believed optimal (under stream of nitrogen) and we compare the obtained results with those observed in other "retinoids solution" samples daily open and close again, simulating the intake from the patient. All samples showed a decrease of all-trans retinoic acid recovery at the end of the study, with a more rapid decline in samples daily open. From our observations, we decided to indicate an expiration date of one months from the date of "solution" preparation. The patient's manipulation brings out a change in the final composition of "retinoids solution".

Bioavailability of two different oral formulations of amoxicillin in healthy subjects.

A study was carried out in 12 healthy volunteers to assess the bioavailability of two different oral formulations of amoxicillin (CAS 26787-78-0). A single 1000 mg oral dose of drug was given according to a randomized two-way crossover design as tablet (treatment A) and capsule (treatment B, Gramidil) and blood samples were drawn at selected times during 24 h. A 7-day wash-out period separated each dose. Amoxicillin plasma concentrations were determined by HPLC, and the stability of drug was studied to verify the possibility of an automated batch processing overnight. Amoxicillin was rapidly absorbed after administration of either formulation and individual plasma concentration-time profiles were constructed. Cmax and AUC values were compare by analysis of variance (ANOVA) followed by Westlake's confidence interval test. 95% confidence limits ranged from 80 to 125% for Cmax and AUC. With respect to tmax, Friedman test was used to compare formulations. It is concluded that the two assayed amoxicillin formulations may be considered to have the same bioavailability.