http://hdl.handle.net/123456789/92 2026-04-18T13:03:26Z http://hdl.handle.net/123456789/1576 EVALUATION OF IRVINGIA KERNEL MUCILAGE AS A MATRIX SYSTEM AND COMPRESSION COATING MATERIAL FOR CONTROLLED DRUG DELIVERY PATANI, BERNARD OPATIMIDI Reliance on imported pharmaceutical excipients has led to increased cost of finished products, necessitating the development of local excipients. Natural polymers have been used extensively as matrix systems for controlled drug release and drug targeting due to their wide-availability, biodegradability, and low toxicity. Previous studies on Irvingia gabonensis mucilage (IGM) suggested controlled release potentials. Therefore, IGM obtained from the seeds of Irvingia gabonensis (O’Rorke) Bail (Irvingiaceae), was evaluated as matrix system for controlled delivery of ibuprofen and as a compression coating material for colon targeted drug delivery. Irvingia mucilage was extracted using established methods. Batches of oven-dried, and freeze-dried IGM were characterized for pH, elemental analysis, morphology and crystallinity. Irvingia matrices were prepared by direct compression and wet granulation with varying drug concentration(10-50%w/w), excipients (lactose, Avicel®, and dicalcium phosphate, DCP), and polymer (xanthan gum, hydroxypropylmethylcellulose) alone and in combination with IGM. The compressional characteristics of IGM and tablets were determined using density measurements, and Heckel and Kawakita equations. The mechanical properties of the tablets were assessed by measuring crushing strength and friability. Drug release from the matrices was evaluated using disintegration and dissolution times. The drug release mechanisms were determined by fitting the dissolution data into classic kinetic equations. Irvingia mucilage was used as compression coating material (300 and 400 mg) for ibuprofen (100 mg). Drug release from the matrices and compression-coated tablets was evaluated in simulated gastric conditions. The results were analyzed using ANOVA at ɑ0.05. Irvingia kernel mucilage was slightly acidic, free of heavy metals, with irregularly shaped particles that exhibited some degree of crystallinity. Irvingia mucilage was directly compressible and formed intact non-disintegrating tablets. The Heckel and Kawakita equations indicated that IGM deformed plastically with fast onset and high amount of plastic deformation compared to xanthan gum and hydroxypropylmethylcellulose. Wet granulation enhanced the mechanical properties of the matrix tablets while increasing ibuprofen concentration generally decreased the mechanical properties and increased drug release. The ranking of dissolution times was xanthan gum>freeze-dried IGM>hydroxypropylmethylcellulose>oven-dried IGM. Irvingia mucilage containing 50%w/w ibuprofen facilitated controlled drug release for over 9 h. Avicel® and DCP improved the mechanical properties of the matrix tablets, facilitated ibuprofen release from IGM, and altered the release kinetics, which was mainly by Korsemeyer-Peppas model while xanthan gum and hydroxypropylmethylcellulose was by Hixson-Crowell. Increasing the proportion of xanthan gum and hyroxypropylmethylcellulose in IGM matrices resulted in decreased rate and percentage of ibuprofen released after 9 h with xanthan gum having the greater effect. The mechanism of drug release at all concentrations for all polymers was super case II except 10%w/w ibuprofen-xanthan gum matrices which was anomalous (non-Fickian diffusion). For the compression-coated tablets, oven-dried and freeze-dried IGM prevented ibuprofen release in conditions mimicking the stomach and small intestine, but fast drug release was obtained in simulated colonic fluid. Irvingia kernel mucilage compared favourably with xanthan gum and hydroxypropylmethyl-cellulose as matrices for controlled drug delivery and could serve as an alternative to the two standard polymers. Irvingia kernel mucilage also showed good potential as a coating material for colon targeted drug delivery 2021-10-01T00:00:00Z http://hdl.handle.net/123456789/269 Entandophragma angolense (WELW) CDC GUM AS A NOVEL BINDER AND MUCOADHESIVE COMPONENT IN ORAL TABLETS ADETUNJI, OLADAPO ADEWALE Mucoadhesive drug delivery systems are designed to prolong drug retention, thus offering advantages over conventional dosages through reduced dosage regimen and improved patient compliance. Natural polymers have gained importance over synthetic materials as excipients in such systems because they are less expensive, biocompatible and biodegradable. Entandophragma angolense gum (ENTA) is used in traditional medicine as a febrifuge, but its excipient properties have not been exploited. This study was carried out to evaluate ENTA as a novel polymer-binder and mucoadhesive component in oral tablets. Entandophragma angolense gum, obtained as dried exudates from the incised trunk of the tree, was characterised using material properties, rheological studies, Fourier-Transform Infrared spectrometer and X-ray diffractometer. Tablets were prepared by Wet Granulation (WG) and Direct Compression (DC) techniques using 2.5 - 10.0 %w/w polymer as binder and 60.0 - 90.0 %w/w polymer as matrix system for controlled release tablets containing ENTA (or official gelatin or hydroxypropylcellulose) with chlorpheniramine maleate (CPM) and ibuprofen as model drugs. Compressional characteristics of the tablets were determined using density measurements, and the Heckel and Kawakita plots. Mechanical and release properties of the tablet formulations were determined by standard methods. Mucoadhesive time (MT) of the tablets were determined ex-vivo in phosphate buffer (pH 7.4) and 0.1M hydrochloric acid (HCl, pH 1.2) using the rotating cylinder method containing excised pig ileum. Data were analysed using descriptive statistics, ANOVA and regression at p = 0.05. The ENTA consisted of irregularly shaped particles with a swelling index of 51.3 %. Rheological studies showed that the final viscosity of 5.0 %w/v ENTA was 258.17 poise. The gum contained hydroxyl groups and was amorphous with some degree of crystallinity. When used as a binder, the ranking of yield pressure was hydroxypropylcellulose > ENTA > gelatin, while the ranking was the reverse for plasticity index. Tablets formulated by WG had higher Tensile Strength (TS) and lower Brittle Fracture Index (BFI) and friability. The ranking of TS was hydroxypropylcellulose > ENTA > gelatin, while those of BFI and friability were the reverse. There was strong correlation(r > 0.98) between binder concentration and dissolution times. When used as polymer for controlled release matrices, the TS increased with binder concentration with tablets prepared by DC technique giving better release profiles than WG technique. The ranking of the disintegration and dissolution times was hydroxypropylcellulose > ENTA > gelatin (p < 0.05). The MT increased with polymer concentration with ibuprofen matrices showing significantly higher MT values than CPM matrices. Generally, the tablets adhered longer in 0.1M HCl, with a ranking of hydroxypropylcellulose (313.00 ± 0.18mins) > ENTA (300.01 ± 0.06mins) > gelatin (207.03 ± 0.11 mins). The polymer matrices provided zero-order drug release for over 14 hours. Entandophragma angolense gum could serve as an alternative binder to official polymers when high mechanical strength is desired. The gum could also serve as a mucoadhesive component in the controlled release of compressed tablets and matrices. Keywords: Entandophragma angolense gum, Polymer-binder, Controlled release tablet, Mucoadhesion, Mechanical and release properties 2013-05-01T00:00:00Z