Avocado starch was extracted from the kernels of the fruit Persea americana Miller (Fam. Lauraceae) and evaluated for its potential as an alternative to maize starch as a pharmaceutical excipient. Its physicochemical and thermal properties were evaluated and compared with those of maize starch. Granules prepared with avocado and maize starch pastes as binder were evaluated for their flow, friability and compaction characteristics. The average yield of starch extracted from the fresh kernels of P. americana was 20.5 AE 0.55% w/w. The scanning electron micrograph (SEM) showed that avocado starch has two characteristic granule shapes; triangular and circular both having an approximate equal distribution. The triangular shaped granules are larger (28 to 32 mm) than the circular (6 to 9 mm). The foaming capacity of avocado starch was 19.05 AE 0.6%, its swelling, moisture uptake and paste clarity were generally lower than that of the maize starch. Avocado starch gel exhibited an extent of syneresis after freeze-thaw that increased cumulatively with increase in number of freezethaw cycles. The glass transition (T g ) and gelatinisation temperatures for avocado starch were higher than that of maize starch. The melting temperatures (T m ), ash value, as well as the various densities of avocado starch showed similarities with those of maize starch. The granules prepared with avocado starch pastes as binder showed superior compactibility and mechanical strength to those of maize starch but with similar flow characteristics. Avocado starch generally showed distinct physicochemical and binder properties with some similarities to the standard maize starch.

Vesicular carriers offer controlled and sustained drug release, improved permeability and protection of the encapsulated bioactives. Ethosomes offer more efficient and enhanced bioavailability better than the older dosage forms owing to the high ethanol content. Ethosomes have potential applications in the development of nanomedicines, including phytomedicines, for the treatment of challenging diseases ravaging the world today. The future holds great prospects in the utilization of vesicular carriers, especially ethosomes, in overcoming peculiar problems of drug delivery.

Tigernut starch has been isolated and modified by forced retrogradation of the acidic gel by freezing and thawing processes. Relevant physicochemical and functional properties of the new excipient (tigernut starch modified by acid gelation and accelerated (forced) retrogradation (ST(AM))) were evaluated as a direct compression excipient in relation to the native tigernut starch (ST(NA)), intermediate product (tigernut starch modified by acid gelation (ST(A))), and microcrystalline cellulose (MCC). The particle morphology, swelling capacity, moisture sorption, differential scanning calorimeter (DSC) thermographs and X-ray powder diffraction (XRD) patterns, flow, dilution capacity, and tablet disintegration efficiency were evaluated. The particles of ST(NA) were either round or oval in shape, ST(A) were smooth with thick round edges and hollowed center while ST(AM) were long, smooth, and irregularly shaped typically resembling MCC. The DSC thermographs of ST(NA) and MCC showed two endothermic transitions as compared with ST(A) and ST(AM) which showed an endothermic and an exothermic. The moisture uptake, swelling, flow, and dilution capacity of ST(AM) were higher than those of MCC, ST(A), and ST(NA). The XRD pattern and moisture sorption profile of ST(AM) showed similarities and differences with ST(NA), ST(A), and MCC that relate the modification. Acetylsalicylic acid (ASA) tablets containing ST(AM) disintegrated at 3±0.5 min as compared with the tablets containing ST(NA), ST(A), and MCC which disintegrated at 8.5±0.5, 10±0.5, and 58±0.8 min, respectively. The study shows the physicochemical properties of tigernut starch modified by forced retrogradation as well as its potential as an efficient direct compression excipient with enhanced flow and disintegration abilities for tablets production.

Tigernut starch is starch extracted from the tubers of Cyperus esculentus L. a perennial herb commonly known as tigernut. The effect of pH on the foaming, gelatinization, solubility, swelling, paste clarity, viscosity, freeze–thaw stability, and binder efficiency of the starch in buffer solutions of pHs 4, 7, and 9.2, representative of acid, neutral, and alkaline pHs were evaluated. Marked pH responsiveness was observed in all these parameters to varying degrees. The foaming capacity, paste clarity, freeze–thaw stability, swelling, and viscosity increased while only the gelatinization temperature decreased with increasing pH. The pastes obtained at pHs 4 and 7 showed marked instability by forming a mass of hard coarse gel with the first freeze–thaw cycle while the paste of pH 9.2 maintained its normal viscoelastic‐gel texture even after the fourth freeze–thaw cycle. The properties of the ascorbic acid granules and tablets produced by wet granulation, using the pastes as binder showed pH‐responsiveness, with the granule formed with the paste of pH 9.2 showing higher mechanical strength and lower disintegration time. This study thus shows the diversity in the physicochemical and binder properties of tigernut starch with changes in pH.

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The findings show that aqueous stem bark extract of Bridelia ferruginea possesses considerable antiplasmodial activity which can be developed in malaria therapy.

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