Research in natural polymeric materials has witnessed growing interest and attention. This is attributable to a number of factors which include their relative abundance, low cost, and biodegrable and eco-firendly profiles. This article reviews the current applications of natural polymeric materials in pharmaceutical formulations. The pharmaceutical applications of some of the traditional and commercially available natural polymers were discussed. Emerging potential pharmaceutical excipients of natural origins were also discussed. The increasing research interests in this group of materials are indications of their increasing importance. It is believed that as technology and testing techniques advance, more understanding of their physicochemical nature would be gained that can enable them to be tailored for wider Pharmaceutical applications than their synthetic counterparts.

The purpose of this work was to evaluate the potential of grewia gum (GG) as a suspending agent in pharmaceutical oral formulation using ibuprofen as model drug. Ibuprofen pediatric suspension (25 mg/5 mL) was formulated with grewia gum (0.5% w/v) as the suspending agent. Similar suspensions of Ibuprofen containing either sodium carboxymethylcellulose (Na-CMC) or hydroxymethylpropylcellulose (HPMC) were also produced. The suspensions were evaluated for ease of redispersion, sedimentation, rheological properties, and the effect of aging on the rheological properties at 25°C. The particle size and particle size distributions of the dispersed solute were determined. The redispersion time was 19, 11, and 0.5 min, respectively, for formulation containing Na-CMC, HPMC, and GG .The sedimentation volumes were 0.05, 0.05, and 0.125 mL, respectively, for Na-CMC, HPMC, and GG . Viscosities of suspensions at spindle speed of 25 rpm were of the order: GG > HPMC > Na-CMC when freshly prepared and of the order: HPMC > GG > Na-CMC within 6 months of storage. The particles size was 72.72, 73.82, 81.93, and 83.41 μm, respectively, for suspensions containing Na-CMC, ibuprofen alone, HPMC, and GG. Greatest hysteresis was observed in formulation containing HPMC. All the formulations were stable. It was our conclusion that the difference in the physicochemical properties of ibuprofen pediatric formulations was influenced more by the suspending agent used in the formulations than the drug. GG combined better redispersion with minimal changes in viscosity on storage compared to Na-CMC and HPMC as suspending agent. Thus GG may serve as a good suspending agent requiring no further aid in suspension redispersibility.

T he purpose of this work was to study the film coating potential of okra gum extracted from pods of Abelmoschus esculentus plant using paracetamol as a model drug. Core tablets of paracetamol were obtained from a pharmacy shop in the locality and the physicochemical properties such as weight, hardness, friability, and disintegration time were evaluated. Aqueous coating suspensions of okra gum and hydroxypropylmethylcellulose (0.6%w/v) were prepared and used to coat the tablets in Hi-coater. The coated tablets were evaluated for weight uniformity, diameter, thickness, hardness, friability, disintegration time, and moisture uptake at controlled humidity. The coating remained intact, durable, and resistant to chipping when challenged to catastrophic fall or rubbed on a white paper. The coated tablets had lower friability, increased disintegration time (24 min) compared to the core (3 min) and improved hardness, but there was no difference in the dissolution profile of the samples from the batches containing okra and hydroxypropylmethylcellulose as film formers. Changes were observed in some of the physicochemical properties of the formulations containing okra gum as with the known film former and it was convenient to conclude that these changes were due to the effect of the mechanical properties of the film formers. It was our conclusion that okra gum is a promising natural, biodegradable, cheap and eco-friendly film former in aqueous tablet film coating operation, particularly when masking of taste or objectionable odor in a solid dosage formulation is desired.

The plant Irvingia gabonensis contains lipids and polymer extractives that can be a good source of excipients for oral pharmaceutical formulations. These constituents are usually extracted from the seeds with the aid of either organic solvents or enzymes. The purpose of this paper was to describe a novel, simpler, cheaper, and safer method for the simultaneous extraction of lipids and gum from I. gabonensis. A 100.0 g of seeds of I. gabonensis in 200 mL deionized water was heated at 78°C in the presence of 2.0 g sodium chloride for 1 h, and the mixture was allowed to stand for the lipids to be separated and removed by filtration. The samples were air dried at 25–30°C. The liquid fraction was centrifuged at 3445 rpm for 30 min, and the supernatant portion containing the gum was freeze dried. The samples were investigated for their true, bulk, and tapped densities as well as particle size and particle size distributions. The rheological, and near infrared absorption spectra as well as thermal behavior of the samples were also studied. The lipid and the polymeric components of I. gabonensis seeds were successfully extracted simultaneously. The true densities of the fatty and gum components were, respectively, 1.000 and 1.544 g/cm3. The melting point of the fat was 40°C and Tg of the gum was 232°C. These values were similar to those described in the literature for the components using the traditional method, demonstrating the effectiveness and efficiency of this simple novel method.