Dissolution Behaviors of Tablet and Capsule Covered with Oblate or Agar Jelly for Taking Medicine Easily

Abstract

Drugs are sometimes covered with oblate or agar jelly. It is said that the medicinal eŠect of drugs covered with oblate is slow, but no studies have reported results conˆrming this. Therefore, we examined the dissolution behavior when the drug was covered with oblate or agar jelly. Three types of commercially available formulations of benzodiazepine were used: medazepam sugarcoated tablets, prazepam uncoated tablets, and clorazepate dipotassium capsules. Dissolution tests were performed using solutions of pH 1.2 and 5.6 to simulate normal gastric juice and gastric anacidity, respectively. Drugs covered with oblate were tested by the paddle method, and those covered with agar jelly were tested using the rotating basket method. Dissolution of clorazepate capsules not covered with oblate increased by approximately 10％ when the pH was adjusted from 1.2 to 5.6, while those of medazepam and prazepam tablets decreased by approximately 40! 60％. In contrast, the dissolution decreased signiˆcantly at both pH values for each drug covered with oblate. Dissolution further decreased when the amount of oblate was doubled. No detectable dissolution of medazepam tablets or of clorazepate capsules occurred when the drug was covered with agar jelly. Dissolution of prazepam tablets covered with agar jelly was only about 10％ at the end of the test. These results indicate that dissolution is slowed and prolonged when a drug is covered with oblate or agar jelly, permitting sustained release of the drug. But, it is necessary to improve a suitable method for the dissolution.

Random Allocated Study of Wrapping Oblate for Prevention of Everolimus-associated Stomatitis in Patients With Metastatic Renal Cell Carcinoma

“…Immune dysregulation is thought to have a role, and several potential mechanisms have been proposed as the pathogenesis of everolimus-associated stomatitis (7,8), considering the clinical resemblance with aphthous ulcer-like lesions. Regarding oblate, wrapping with oblates lowers and prolongs dissolution of tablets or capsule formulations by forming a mucous layer of gelatinized oblate that acts as a barrier and reduces the rate at which the solution permeates into the structural part of the drug and the rates of disintegration, dispersion, and dissolution of the drug (16). Therefore, in order to reconcile those findings, we reason that taking everolimus without oblate would induce a sharp increase in the everolimus concentration up to Cmax, and the excessively increased peak concentration might trigger the development of stomatitis.…”

“…Oblate is a thin film composed of starch that enables slow or prolonged dissolution of drugs when wrapped around a capsule or tablet. When drugs were wrapped in oblate, dissolution was found to be delayed, and the dissolution rate remarkably decreased relative to that of the drug not wrapped in oblate (16). Although the preventive effect and mechanism of oblate wrapping for prevention of stomatitis have not been studied, some clinicians and patients have used anecdotally reported application of oblate for treatment of everolimus or other tyrosine kinase inhibitor (TKI)-related stomatitis with success.…”