Transdermal delivery of bovine serum albumin using snail mucin

The study aimed at evaluating the bioadhesion properties and penetration enhancing effect of mucin-based bovine serum albumin (BSA) transdermal patches. Mucin was extracted from the giant African snail Archachatina maginata by differential precipitation with acetone and alum. Various batches of BSA loaded transdermal film patches were prepared with the precipitated mucin and varying volumes (0, 0.2 and 0.5 mL) of polyethylene glycol (PEG) as plasticizer. Prepared patches were evaluated for weight uniformity, patch thickness, folding endurance, moisture content and uptake, bioadhesion, drug content and in vitro and ex vivo diffusion studies. Differential scanning calorimetry analysis showed no interaction between BSA and mucin. Mean weight range from 0.11±0.02 to 0.13±0.05 g, moisture content (32 %) and moisture uptake was highest with patches prepared with acetone-precipitated mucin (up to 129 %) and decreased as PEG concentration increased. All the patches showed bioadhesion values between 1.70 - 1.98 g/sec. Drug diffusion across treated rat skin was 47 % after 12 h from patches prepared from acetone-precipitated mucin. Thus, snail mucin showed promise as a transdermal drug delivery base in the formulation of BSA patches because of its bioadhesion property and penetration enhancing effect.Keywords: Bioadhesion, drug diffusion, proteins, mucin, transdermal deliver

Some Physical Properties of Vernonia amygdalina and Garcinia kola Microspheres Prepared with High Molecular Weight Polyethylene Glycols

The effect of polymer concentrations on some of the physicochemical properties of Vernonia amygdalina (Linn) and Garcinia kola (Heckel) extracts loaded microspheres was evaluated. Microspheres of the aqueous extracts was prepared by emulsion solvent evaporation using polyethylene glycol (PEG) mixtures of molecular weight 4000 and 6000 at different ratios of 1:0, 0:1, 1:1, 1:2 and 2:1 while the amounts of the extracts incorporated was constant for all ratios. The microspheres were evaluated for their particles sizes, yield, flavonoid content, loading efficiency, moisture loss and flow properties. In-vitro release studies were carried out by monitoring flavonoid release rate from the microspheres. The microspheres were spherical and uniformly shaped and exhibited good flow characteristics. Their size range, yield, loading efficiency, moisture loss and flavonoid content were 76 - 83 \u3bcm, 49 - 76 %, 47 - 82 %, 2.18 - 4.60 % and 17.10 - 23.80 mg%, respectively for V. amygdalina and 144 - 160 \u3bcm, 50 - 68 %, 51 - 68 %, 3.00 - 4.41 % and 20.00 - 28.70 mg%, respectively for G. kola. Flavonoids release from the microsphere was up to 90 % within 1 h and it followed a matrix release kinetic model with a super case-II transport mechanism. The concentrations of the polymers affected the yield, loading efficiency, moisture loss and the extent of flavonoid release of the microspheres but had no effect on their particle sizes and flavonoid content. These results may find useful application in the delivery of V. amygdalina and G. kola extracts since the combination of PEG of different molecular weights resulted in microspheres with good physicochemical and release properties

Box Behnken design in the optimization of two disintegrants and a sublimating agent in the formulation of fast disintegrating tablets of diclofenac

The aim of the study was to formulate fast disintegrating tablets of diclofenac with a combination of disintegrants and sublimating agent, and to optimize the concentrations of the disintegrants and the sublimating agent for a faster tablet disintegration. A Box Behnken experimental design model was used to generate 17 possible combinations of two disintegrants (maize starch BP and croscarmellose sodium) and a sublimating agent (camphor). Using these combinations, 17 batches of diclofenac sodium tablets were prepared by direct compression and subjected to disintegration and crushing strength tests in order to select optimal batches. Bulk formulation of granules and tablets of the optimal batches was carried out and evaluated for granule flow properties (bulk and tapped densities, angle of repose, Hausner’s ratio and Carr’s index) and post compression parameters (weight uniformity, tablet dimensions, crushing strength, friability, disintegration and dissolution). Drug-excipient interaction studies were also carried out using DSC and FTIR. Results from the granule analysis of the optimal batches indicated free flowing granules. The disintegration times and crushing strengths of the tablets were < 3 min and > 4 kp respectively and they corresponded with the values obtained from the experimental design model. All the batches of tablets released up to 95 % of their drug content within 30 min. Drug-excipient compatibility study revealed no interaction between diclofenac sodium and the excipients used. Fast disintegrating tablets of diclofenac were thus successfully formulated using a Box Behnken design in the combination of two disintegrants and a sublimating agent. Batch B14 formulation with a disintegration time of 26.55 seconds and a crushing strength of 4.25 kp was the most superior of the optimized batches.Keywords: diclofenac, disintegrants, camphor, Box-Behnken, optimization, tablet

Antimicrobial activities of creams prepared with methanol and aqueous leaf extracts of Ricinus communis L. (Euphorbiaceae)

The aqueous and methanol crude extracts of the leaves of Ricinus communis L. (Euphorbiaceae) have been reported to possess antimicrobial activity. This study was carried out to investigate the antimicrobial activity of the cream formulations of these leaf extracts against some pathogens. The extract of R. communis was obtained by maceration of the blended leaf using methanol or distilled water. Topical creams were prepared by mixing 6 g of cetomacrogol ointment BP with an aqueous phase prepared by dispersing 4 g of the extract in 10 mL of purified water. Agar well diffusion method was used to determine the antimicrobial activity of the creams against test organisms using diameter of zones of inhibition as a measure of activity. Plain creams formulated and a commercial antimicrobial cream were also tested. The yield of the extraction was 7.27 and 6.73 % with methanol and water respectively. Extracts were dark green in colour with a pungent odour. The colours of the creams formulated were also dark green while their pH values range from 2.54-5.01. Diameter of zones of inhibition produced against gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis) and gram-negative bacterium (Pseudomonas aeruginosa) were 26, 18 and 14 mm for the methanol extract and 16, 13 and 11 mm for the aqueous extract. Escherichia coli and Candida spps were not inhibited by both extracts. The antimicrobial microbial activity of the methanol extract cream was comparable to that of the commercial cream. The plain creams showed no antimicrobial effect on all test organisms. The creams of methanol and aqueous extract of R. communis L. leaf have significant antimicrobial activity against test organisms except E. coli and Candida spps. The methanol extract cream would be useful in skin infections where the pathogen S. aureus is implicated.Keywords:  Ricinus communis, zones of inhibition, cetomacrogol emulsifying ointment BP, maceratio