Untitled

Abstract

The stability of misoprostol oil is significantly improved in a hydroxypropyl methylcellulose (HPMC) dispersion (1:100). In order to assess the effect of water on misoprostol stability, the rate of misoprostol degradation was investigated in the misoprostol/HPMC dispersion at 55 degrees C, along with the water sorption isotherm, under seven different relative humidity (RH) conditions ranging from 0 to 81%. The results indicated that the first-order rate constants of misoprostol degradation increased in a concave-up fashion as the water content of the dispersion increased. Below 30% relative humidity (approximately 2% water), the first-order rate constants of misoprostol degradation were found to be minimum. The results of the stability study were interpreted in terms of the changing structure of HPMC as it related to the mobility of water and misoprostol within the HPMC dispersion.

Instability of Misoprostol Tablets Stored Outside the Blister: A Potential Serious Concern for Clinical Outcome in Medical Abortion

“…Misoprostol, an E1-type prostaglandin, is known to be very unstable and must be stabilized in the form of a solid dispersion with Hydroxypropyl Methylcellulose (HPMC). The HPMC is designed to protect the misoprostol and to slow down the water penetration [26] .…”

“…misoprostol, from ambient humidity. [26] The observed increase in tablets’ diameter and thickness shows that the atmospheric water penetrating into tablets makes the HPMC that they contain inflate. HPMC used in production of misoprostol may contain as much as 5% water.…”

“…In our study, with water content reaching 5.53% at 24 hours, the protection of misoprostol by HPMC is widely exceeded. Kararli & Calatano [26] postulated that the stability of misoprostol was found to be at a maximum for an increase in water level below 2%, outside the intrinsic water content of the HPMC.…”

“…Therefore the role of water in the degradation of misoprostol is twofold, that of a plasticizer and a catalyst. [19] , [26] As a consequence, it initiates the degradation of misoprostol in inactive substances.…”

Method to determine stability and recovery of carboprost and misoprostol in infusion preparations

“…A tablet weight (0.2 g) of placebo powder was prepared from the mixture of 2 mg hydrogenated castor oil, 10 mg sodium starch glycolate, 168 mg microcrystalline cellulose and 20 mg hydroxypropyl methylcellulose [9,12,13]. Blank water extract was prepared by mixing, homogenizing and vortexing 2 ml of water with placebo powder for 5 min.…”