Formulation Development of Azadirachta indica Extract as Nanosuppository to Improve its Intrarectal Delivery for the Treatment of Malaria.

BACKGROUND: Previous folkloric and experimental reports have demonstrated the antimalarial efficacy of Azadirachta indica (AZA) extracts. However, one of the major challenges facing its application for the clinical treatment of malaria is the design of an acceptable dosage form. OBJECTIVE: Consequently, we developed AZA extract-loaded nanostructured lipid carriers (NLC) for the formulation of suppositories, denoted as nanosuppositories, for intrarectal treatment of malaria. METHODS: Various batches of NLC-bearing AZA extract were formulated based on lipid matrices prepared using graded concentrations of Softisan®154 and Tetracarpidium conophorum or walnut oil. NLC was investigated by size and differential scanning calorimetry (DSC). Suppository bearing AZA extract-loaded NLC was developed using cocoa butter or theobroma oil, and their physicochemical properties were profiled. In vitro drug release and in vivo antimalarial activity (using Plasmodium berghei-infected mice) were investigated. RESULTS: NLCs exhibited sizes in nanometers ranging from 329.5 - 806.0 nm, and were amorphized as shown by DSC thermograms. Nanosuppositories were torpedo- or bullet- shaped, weighing 138 - 368 mg, softened/liquefied between 4.10 - 6.92 min, and had controlled release behaviour. In vivo antimalarial study revealed excellent antimalarial efficacy of the nanosuppositories comparable with a commercial brand (Plasmotrim®) and better than the placebo (unloaded nanosuppository), and without toxic alterations of hepatic and renal biochemical factors. CONCLUSION: Thus, AZA extract could be rationally loaded in nanostructured lipid carriers (NLC) for further development as nanosuppository and deployed as an effective alternative with optimum convenience for intrarectal treatment of malaria.

Profiling the physicochemical and solid state properties of edible Tetracarpidium conophorum oil and its admixtures for drug delivery

Abstract The study is aimed at investigating the functional physicochemical and solid state characteristics of food-grade Tetracarpidium conophorum (T. conophorum) oil for possible application in the pharmaceutical industry for drug delivery. The oil was obtained by cold hexane extraction and its physicochemical properties including viscosity, pH, peroxide, acid, and thiobarbituric acid values, nutrient content, and fatty acid profile were determined. Admixtures of the oil with Softisan®154, a hydrogenated solid lipid from palm oil, were prepared to obtain matrices which were evaluated by differential scanning calorimetry, fourier-transform infrared spectroscopy, and x-ray diffractometry. Data from the study showed that T. conophorum oil had Newtonian flow behaviour, acidic pH, insignificant presence of hyperperoxides and malondialdehyde, contains minerals including calcium, magnesium, zinc, copper, manganese, iron, selenium, and potassium, vitamins including niacin (B3), thiamine (B1), cyanocobalamine (B12), ascorbic acid (C), and tocopherol (E), and long-chain saturated and unsaturated fatty acids including n-hexadecanoic acid, 9(Z)-octadecenoic acid, and cis-13-octadecenoic acid. The lipid matrices had low crystallinity and enthalpy values with increased amorphicity, and showed no destructive intermolecular interaction or incompatibility between T. conophorum oil and Softisan® 154. In conclusion, the results have shown that, in addition to T. conophorum oil being useful as food, it will also be an important excipient for the development of novel, safe, and effective lipid-based drug delivery systems.