a b s t r a c tThe great challenge in using native degradable polysaccharides for the development of drug delivery systems is their high aqueous solubility, which may contribute to the undesirable premature and localized release of the drug. Multiparticulate systems showing simultaneously specific biodegradability and pHdependent drug release were prepared based on chitosan (CS), amidated pectin (PC), and calcium ions, using triamcinolone (TC) as model drug. Hidroxypropylmethyl cellulose phthalate (HPMCP) and cellulose acetate phthalate (CAP) were successfully incorporated into the system and aided the target action of the carbohydrates. Particles were characterized for size distribution, morphology, swelling behavior and dissolution tests in media simulating the gastrointestinal tract. The addition of CAP and HPMCP resulted in the highest control over the drug release in all media. CAP:TC formulation presented the slowest drug release rate, of only 1.33%, in acidic medium after 2 h, while the control formulation released 45.52% after the same time.

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Halcinonide is a high-potency topical glucocorticoid used for skin inflammation treatments that presents toxic systemic effects. A simple and quick analytical method to quantify the amount of halcinonide encapsulated into lipid nanoparticles, such as polymeric lipid-core nanoparticles and solid lipid nanoparticles, was developed and validated regarding the drug's encapsulation efficiency and in vitro permeation. The development and validation of the analytical method were carried out using the high performance liquid chromatography with the UV detection at 239 nm. The validation parameters were specificity, linearity, precision and accuracy, limits of detection and quantitation, and robustness. The method presented an isocratic flow rate of 1.0 mL.min -1 , a mobile phase methanol:water (85:15 v/v), and a retention time of 4.21 min. The method was validated according to international and national regulations. The halcinonide encapsulation efficiency in nanoparticles was greater than 99% and the in vitro drug permeation study showed that less than 9% of the drug permeated through the membrane, indicating a nanoparticle reservoir effect, which can reduce the halcinonide's toxic systemic effects. These studies demonstrated the applicability of the developed and validated analytical method to quantify halcinonide in lipid nanoparticles.Uniterms: Halcinonide/encapsulation efficiency. Halcinonide/quantification. Polymeric lipid-core nanoparticles. Solid lipid nanoparticles. Topical administration. Toxicity. High performance liquid chromatography/method validation.

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