Solidified reverse micellar solutions (SRMS): A novel approach for controlling drug release from various lipids based drug delivery systems

Solidified reverse micellar solutions (SRMS) are reverse micelles containing lecithin and a triglyceride, for example, SOFTISAN®142, which is hydrogenated coco glyceride. SRMS transform into a lamellar mesophase after melting on contact with water; this transformation enables controlled release of solubilized drugs. They offer potentials for sustained drug delivery of both hydrophilic and lipophilic drugs. SRMS have the advantage of providing more flexibility in controlling the drug release and protecting the encapsulated ingredients from chemical degradation. SRMS based systems influence the absorption of active ingredients through different mechanisms to modify the release of active ingredients, and improve drugs bioavailability. The types of SRMS-based drug delivery systems include solid lipid nanoparticles (SLN), solid lipid microparticles (SLM), tablets and suppositories amongst others. The work exhaustively reviews the advances in SRMS based carriers. Its formulation methods, characterisation and delivery systems were discussed in details.Key words: Solidified reverse micellar solutions (SRMS), lipids, wide angle X-ray diffraction analysis (WAXD), small angle X-ray diffraction analysis (SAXD), lipid absorption

ARTEMETHER LUMEFANTRINE LOADED LIPOSPHERES EVALUATION OF PROPERTIES OF SOLUTOL HS 15 AND SOLUPLUS ON THE IN VITRO PROPERTIES

To formulate artemether lumefantrine loaded lipospheres and to evaluate the effect of excipients on the in vitro properties  Materials and methods: Lipospheres were formulated using goat fat (70 percentage) and Phospholipon 90H (70 percentage) as the lipid matrix, Solutol HS 15 and Soluplus were used respectively as surfactants.  The lipospheres were formulated by melt homogenization and analysed for drug content, encapsulation efficiency (EEpercentage), particle size and pH stability. In vitro release was studied in simulated gastric fluid (SGF, 1.2) and simulated intestinal fluid (SIF, 7.2).       Results: Lipospheres formulated with Solutol had particle size range of 24.16 to 30.89 μm, while those formulated with Soluplushad particle size range of 24.72 to 74.16 μm. The formulations showed a decline in pH at 30 days. The EE of artemether range from 71.80 to 75.30 percentage for lipospheres formulated with Soluplus, while those formulated with Solutolhad EEpercentage of 65.30 to 75.02 percentage. Also, the EEpercentage of lumefantrine ranged from 76.36 to 88.99 percentage for lipospheres formulated with Soluplus, while those containing Solutolhad EE range of 73.22 to 85.06 percentage. Formulations exhibited sustained release properties with maximum release of at 6 h, however, lumefantrine exhibited higher release than artemether in SIF (p less than 0.05) and significantly lower release in SGF (p less than 0.05).                                                                                                                                           Conclusion: Lipospheres exhibited good properties as a delivery system for artemether-lumefantrine. Keywords: Goat fat, phospholipid, antimalaria, melt homogenization, loading capacit

Evaluation of binder and disintegrant properties of starch derived from Xanthosoma sagittifolium in metronidazole tablets

The aim of the study was to formulate metronidazole tablets using starch from Xanthosoma sagittifolium as binder and disintegrant in metronidazole tablets. Metronidazole tablets were produced by wet granulation method using X. sagittifolium starch as binder at concentrations of 5, 10, 15 and 20% w/w, and as disintegrant (5% w/w). The micromeritic properties of the granules were determined using the direct and indirect methods. The necessary official and non official tests were performed on the tablets to include uniformity of tablets weight, content of active ingredient, disintegration test, hardness, friability tests and in vitro drug release. Also, the phytochemical constituents of the starch were determined. The results show that the granules had a good flow and values obtained were within the specified limits for the production of good quality tablets. Deviations obtained from the tablet weight uniformity test were significantly (p< 0.05) below 5%. Tablets disintegration time ranged from 3.00 ± 0.08 min to 14.00 ± 0.10 min for M1 and M4 tablets formulated with 5 and 20% of X. sagittifolium starch respectively. The tablets hardness ranged from 7.20 ± 1.25 to 8.55 ± 1.17 kgf. In vitro release showed that M1 tablets had T25, T50 and T90 % at 5, 13 and 23 min respectively, while M4 tablets had T25, T50 and T90 % at 8, 18 min and were unable to release 90% of metronidazole at 30 min. Phytochemical analysis showed that the starch contained alkaloids, glycosides, carbohydrate and steroids. Therefore, starch from X. sagittifolium could be used to formulate metronidazole tablets for improved oral bioavailability of metronidazole.Keywords: Xanthosoma sagittifolium starch, tablets binder and disintegrant, metronidazoleAfrican Journal of Biotechnology Vol. 12(20), pp. 3064-307

IN VITRO PROPERTIES OF SOLID LIPID MICROPARTICLES (SLMS) LOADED WITH METHANOLIC EXTRACT OF GARCINIA KOLA (HECKEL) SEED

Objective: The decline in the use of herbal medicine especially in the Western world may be due to lack of readily available market brand formulations and the fact that most herbal remedies are taken as tea, decoctions and infusions. The taste of some of these herbal drugs is not palatable, and some have unpleasant odour and colour hence, the need to formulate these drugs in form of encapsulated dosage forms. The objective of the work was to formulate solid lipid microparticles (SLMs) loaded with the methanolic extract of Garcinia kola seed. Methods: The SLMs containing 1 and 3 % of Garcinia kola seed extract were formulated using fat from Capra hircus and Phospholipon® 90H (3:1). The particle morphology and size, encapsulation efficiency (EE%), pH, in vitro release and the inhibition zone diameter (IZD) of the SLMs were determined. Results: The results showed that the extract was very bitter while, the encapsulated G. kola had slight bitter taste. The pH remained in the acidic region from 1 to 30 days. Particle size of 28.65 ± 1.13 and 29.49 ± 1.24 µm were obtained for SLMs loaded with 1 and 3 % of the extract respectively. SLMs had high EE% of 94 % and also exhibited good release of the extract in simulated intestinal fluid (SIF, pH 7.2). Garcinia kola-loaded SLMs had good activity against Staphylococcus aureus and no action against Escherichia coli. Conclusion: Therefore, Garcinia kola seed extract could be formulated as SLMs in order to mask its bitter taste and improve compliance. Â