Introduction: Curcumin faces a major challenge in clinical use due to its poor aqueous solubility, which affects its bioavailability over oral use. The present study was carried out to overcome this problem. Methods: An amorphous micellar curcumin-spray dried powder (MC-SDP) with selfassembled casein was prepared by the addition of sucrose as a protectant. The dry powder of curcumin-loaded micelles was obtained by a spray-drying technique in the presence of sucrose as a protectant. The MC-SDP in the form of dry powder was further developed into tablets to investigate the dissolution profile. The physical properties of preformed powder were characterized by differential thermal analysis (DTA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). Quantitative analysis in the form of solutions was analyzed by high-performance liquid chromatography (HPLC). Results: The physical properties demonstrated that MC-SDP varies from dented to smoother surfaces as a function of sucrose. Furthermore, melting transitions of curcumin in the form of MC-SDP were broadened in all sample mixtures, as observed in the DTA thermogram. The XRD spectra showed that the sharp and very intense peaks of single curcumin crystalline structure no longer existed in all MC-SDP forms, indicating that the mixtures were amorphous. Moreover, a further dissolution study of MC-SDP showed a significant increase of drug dissolved with the presence of sucrose, where >80% of curcumin from MC-SDP was dissolved within 30 min. Conclusion: The study demonstrated the manufacture of micellar spray-dried powder that would contribute to the development of oral delivery of curcumin.

Quercetin has been proposed to exhibit numerous pharmacological benefits yet suffer low bioavailability due to the extremely low solubility. A research to study the impact of cocrystallization of quercetin with succinic acid on the solubility and dissolution profile has been performed. Cocrystallization in molar stoichiometry of 1:1 was carried out via liquid assisted grinding with methanol in ball milling apparatus. Cocrystal formation was identified by hot stage microscopy (HSM) at first, then cocrystal phase was characterized using differential thermal analysis (DTA), powder X-ray diffractometry (PXRD), scanning electron microscopy (SEM), and fourier-transform infrared (FT-IR) spectroscopy. Solubility and dissolution test were conducted as well. DSC thermogram exhibits new endothermic peak at 280.32°C representing the melting point of cocrystal phase alongside with endothermic point of pure compounds. Powder X-ray diffractograms show new diffraction peaks on behalf of cocrystal formation at 2θ=8.92, 9.88, 13.04, 29.78, 35.35°. FT-IR spectroscopy reveals band shifting in –OH group region. On SEM photographs, one can observe crystal habit of succinic acid being covered by crystal with different habit. This indicates that quercetin interacts with succinic acid only on the surfaces and causes imperfect formation of cocrystal phase. Cocrystallization quercetin improves solubility by 1.62 times higher and dissolution rate by 1.25 higher than pure quercetin (one-way ANOVA, p < 0.05).

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Objectives Cyclodextrin’s ability to form an inclusion complex with a guest molecule is a function of two factors. The first is steric and depends on the relative size of cyclodextrin cavity to the guest molecule, while the second is the thermodynamic interaction between the different system components. This study therefore aims to determine the effect of β-cyclodextrin and hydroxypropyl-β-cyclodextrin as complex formers, on thermodynamic parameter values (ΔH, ΔG, and ΔS) in the formation of inclusion complex with p-methoxycinnamic acid (pMCA). Methods The pMCA complex formation with β-cyclodextrin or hydroxypropyl-β-cyclodextrin was determined in 0.02 pH 4.0 M acetate buffer and 0.02 M pH 7.0 phosphate buffer, with a 0.2 µ value at 32, 37, and 42 ± 0.5 °C. This experiment was carried out in a waterbath shaker until a saturated solution was obtained. Subsequently, pMCA concentration was determined using UV spectrophotometer at the maximum pMCA wavelength, at each pH. Results The result showed pMCA formed inclusion complex with β-cyclodextrin or hydroxypropyl-β-cyclodextrin and exhibited increased solubility with increase in β-cyclodextrin or hydroxypropyl-β-cyclodextrin concentration. This temperature rise led to a decrease in the complex’s constant stability (K). Furthermore, the interaction showed a negative enthalpy (∆H<0) and is a spontaneous processes (∆G<0). At pH 4.0, an increase in the system’s entropy occurred (∆S>0), however, at pH 7.0, the system’s entropy decreased (∆S<0). Conclusions The rise in pMCA solubility with increase in cyclodextrin solution concentration indicates an inclusion complex has been formed, and is supported by thermodynamic data.

Background Meloxicam (MLX) is a potent non-steroidal anti-inflammatory drug with poor solubility. Solid dispersion (SD) is an effective formulation strategy to improve the dissolution rate of poorly water-soluble compounds. Hydroxy propyl methyl cellulose (HPMC) as an inert polymer carrier and nicotinic acid (NA) as disturbance can be used as a matrix of SD. The aim of this study was to determine the effect of MLX-HPMC-NA SD on the solubility and dissolution of MLX. Methods SD was prepared by the solvent evaporation technique with methanol being used as a solvent. Methanol was evaporated at room temperature. SD of MLX was prepared involving various matrix compositions at MLX:HPMC:NA ratios of 1:1:1 (SD1), 1:1:2 (SD2), 1:2:1 (SD3), and 1:2:2 (SD4). Results The solubility profile of MLX in SD3 (64.34 ppm) showed a higher improvement than the physical mixture (15.99 ppm) and pure MLX (6.89 ppm). This increase might be due to the formation of molecular dispersion of MLX in the polymer as hydrophilic matrix and NA have both donor-acceptor sites for hydrogen bonding interactions. The dissolution profile of SD3 also showed the highest improvement. The melting endotherm of SD3 was detected at 219.5 °C, in which case it originated from NA rather than from MLX, showing that MLX was molecularly dispersed and amorphous. Conclusions MLX solubility and dissolution profile could be improved by the SD technique with a matrix of HPMC and NA. The best result was given by SD3 with an MLX:HPMC:NA ratio of 1:2:1. Based on the characterization study, it is predicted that hydrophilic polymer and hydrogen bonding interactions play important roles in MLX solubility or dissolution rate improvement.