Sustained Release of Diclofenac from Polymer-Containing Suppository and the Mechanism Involved

Abstract

Sustained release of diclofenac sodium (DcNa) from suppositories composed of triglycerides and polymer was investigated by dissolution testing through an artificial membrane. DcNa was slowly released from a suppository containing carboxyvinyl polymer (CVP), and the extent of the release decreased with the amount of CVP added. Little effect was noted with the addition of other water-soluble polymers, such as hydroxyethylcellulose (HEC), xanthan gum, and polyvinylalcohol (PVA). When sodium benzoate was used instead of DcNa, a similar result was obtained with the addition of CVP. The result of release rate analysis together with the viscosity and pH in these cases showed that the reduction of solubility and diffusion due to sodium exchange between DcNa and CVP played an important role in the sustained release from the suppository. Also, in comparison with the results when CVP was not used, the plasma concentration profile of diclofenac after the administration of CVP suppository displayed a twofold longer half-life time.

Proposed Design of a Dissolution Apparatus for Vaginal Formulations Containing Probiotics

“…In order to control the mass-medium ratio, several means have been employed that include a wire-mesh basket (12) or a membrane to separate the sample chamber from the reservoir (13). In these models, also, the volume of dissolution fluid is large and does not match the vaginal discharge volume.…”

Sildenafil vaginal suppositories: preparation, characterization,in vitroandin vivoevaluation

“…The thermogram of sildenafil showed no endothermic peak due to its amorphous nature. The sildenafil vaginal suppository showed endothermic peak that is corresponding to the melting points of Witepsol H-15 with no extra peaks, suggesting no crystalline change of the ingredients during the preparation process of the suppository formulation [51][52][53] .…”

Symptom control in cancer patients: the clinical pharmacology and therapeutic role of suppositories and rectal suspensions

“…The former has a higher maximum concentration (C-max) and a shorter time to maximum concentration (T-max) [174]. Sustained-released diclofenac suppositories are produced by adding soya lecithin to a glyceride base or by adding carboxyvinyl polymer to a triglyceride base [11,69,174]. When Witepsol (a mixture of trigylcerides, diglycerides, and monoglycerides) is used as a base, the absorption of diclofenac is dependent upon the content of Witepsol W-35 in the suppository.…”