Evaluation of Cactus (Opuntia stricta) Mucilage as Sustained Release Excipient in Diclofenac Sodium Matrix Tablet Formulation
No Thumbnail Available
Date
2018-12
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa Universty
Abstract
Nowadays, plant derived polymers have received increasing attention due to their diverse pharmaceutical applications in controlled drug delivery. Among these natural polymers, mucilages and gums are versatile excipients for pharmaceutical formulations. The main objective of the present study was to evaluate cactus (Opuntia stricta) mucilage as a matrix forming polymer for sustained release tablet formulations of diclofenac sodium. In this study, mucilage from cactus cladode was extracted by using distilled water as extracting solvent and ethanol as mucilage precipitant. The mucilage powder was characterized for physical properties. A 1% w/v solution of the mucilage in water gave a pH of 6.40, which shows low irritability potential in uncoated tablets. The powder was fairly flowing on the funnel, showing the need of other compressible excipient and granulation to make it better flowable. The Kawakita constants of compressibility and cohesiveness showed that the powder is compressible and cohesive. The solubility and swelling power of the Opuntia stricta were generally low at low temperature (20 °C), but increase significantly at higher temperature (85 °C) (p < 0.05). Percent moisture sorption ranged from 7.61% at 15% and 79.9% at 100% RH. On viscosity test, the mucilage showed pseudo-plastic property.
The granules prepared with water as granulating solvent showed excellent flow property. The formulated matrix tablets were found to have good uniformity of weight. The tablets of different batches of directly compressed formulations were found to possess acceptable hardness within the range of 76.23 ± 0.24 to 80.51 ± 0.81. Crushing strength of wet granulated formulations was higher than the directly compressed formulations. The in vitro dissolution study demonstrated that both directly compressed and wet granulated formulations using Opuntia stricta mucilage effectively sustained diclofenac release for more than 12 h, even at low concentration, 10 %. However, granulation showed a better matrix for sustained release of drug from the tablets. All the formulations showed good linearity with respect to Korsmeyer-Peppas equation with 0.45 ≤ n ≤ 0.89 indicating that, non Fickian diffusion was the predominant mechanism of drug release from these formulations. So, Opuntia stricta mucilage can be used as alternative pharmaceutical excipient in the formulation and manufacture of sustained release matrix tablets.
Description
Keywords
Opuntia stricta mucilage, direct compression, wet granulation, matrix tablets, in vitro drug release