Plant polysaccharides include pectins, which are responsible for an important role in plant physiology and are part of the plant cell wall. These compounds are known as gelling and stabilizing agents, which are widely used in the food industry. The scientific literature lacks precise information on the spectroscopy of apple pectin and citrus pectin. Therefore, the aim of this work was to test and compare the physicochemical properties of these compounds. The curves of FT-IR, NMR, ESI-MS, and thermogravimetric analysis (TGA) of pectin samples were measured and discussed. The analysis of the spectroscopic results confirms that the isolated pectins using various enzymes (xylanase and cellulase) have a structure similar to the commercially available pectin (PectaSol-C), with a noticeable change in morphology. These characteristics are helpful for further basic research and application.

One strategy for improving the dissolution of poorly water soluble drugs is to prepare solid dispersions such as binary mixtures with hydrophilic carriers. These mixtures are generally characterized by better solubility than those of the individual components from which they are formed. In the present study, solid dispersions of ketoconazole (KET) with Pluronic F127 (PLU) were prepared by the grinding method. Solid–liquid equilibria in the system being studied were investigated by differential scanning calorimetry. A phase diagram for the whole range of compositions was constructed. The investigation revealed that ketoconazole and Pluronic F127 form a simple eutectic system containing 4.4 % w/w of ketoconazole at the eutectic point. The results of Fourier transform infrared spectroscopy and X-ray powder diffractometry studies of obtained mixtures suggest that there is no drug-carrier interaction and both components are crystalline in the solid dispersion with the whole range of composition. The prepared mixtures show an appreciable improvement of the dissolution rate of KET in 0.5 % w/v sodium lauryl sulfate. The improvement of the dissolution rate of drug is additionally increased by effective solubilization.

In recent years, considerable attention focuses on making sustained release dosage forms also containing solid dispersions. The objective of this study is evaluation of imatinib base (IMA) solid dispersion physicochemical properties which can be useful to controlled release solid dosage formation. The solid dispersions were obtained by kneading method, containing of 10–90% w/w Pluronic F127 (PLU). Drug dissolution test was determined by rotating-disc system method in 0.1 M hydrochloric acid (pH 1.2) and phosphate buffer (pH 6.8). XRD, DSC, FTIR, and SEM observations were performed to evaluate the physical characteristics of solid dispersions. These studies showed that there was no chemical interaction of the IMA with PLU in the solid state and revealed that IMA and PLU form a simple eutectic phase diagram. Our research has shown that the dynamics of the release of imatinib base from solid dispersions with Pluronic F127 depends on the pH of dissolution medium. At pH 1.2, the presence of polymer in solid dispersion causes delaying of drug release due to formation a viscous gel layer, whereas at pH 6.8 significant enhancement of the drug dissolution rate from solid dispersions has been observed compared to pure IMA. The highest improvement was observed in solid dispersions containing 20 and 30% w/w polymer. The present investigation confirmed that the hydrophilic polymer Pluronic F127 could be applied as a suitable matrix to design modified release formulations of imatinib base.

Enhancement of the dissolution rate of poorly soluble compounds through the formation of drug–drug eutectics was investigated using fenofibrate and acetylsalicylic acid. Solid–liquid equilibria in the system under study were investigated by differential scanning calorimetry (DSC). The phase diagram for the whole range of compositions was constructed. In addition, existence of a metastable polymorph of fenofibrate has been confirmed. The investigation has revealed that acetylsalicylic acid and fenofibrate form a simple eutectic mixture containing 0.958 mol fraction of fenofibrate at the eutectic point. Dissolution rate improvement of fenofibrate correlated with the phase diagram. The amount of fenofibrate released from the solid dispersions that contained fenofibrate as the eutectic mixture with acetylsalicylic acid was at least threefold higher compared to untreated fenofibrate.

Prepared solid dispersions were applied to a drug with low water solubility to improve its dissolution rate. Fenofibrate (FEN) is a Biopharmaceutical Classification System (BCS) class-II (poorly water-soluble) drug, and its bioavailability is limited by the dissolution rate. The physical state of FEN in solid dispersions with Pluronic F127 (PLU) prepared using the fusion method was assessed using Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRPD), and differential scanning calorimetry (DSC). The DSC investigation revealed that FEN and PLU form a simple eutectic system. The DSC, XRPD, and FTIR studies of the investigated solid dispersions revealed no interaction between FEN and PLU. The intrinsic dissolution rate (IDR) of FEN from solid dispersions was significantly increased compared with the pure drug. The enhancement in the intrinsic dissolution rate was approximately 134-fold for solid dispersions containing 30/70 % w/w of FEN/PLU.

The objective of the present investigation was to study the effect of eutectic formation on in vitro dissolution of simvastatin (SIM) released from mixtures with acetylsalicylic acid (ASA) prepared by a grinding method. SIM–ASA mixtures were characterized by means of differential scanning calorimetry (DSC), infrared spectroscopy (IR), X-ray powder diffractometry (XRPD), and in vitro dissolution tests. IR spectroscopy and XRPD studies indicated no interaction between SIM and ASA in the solid state. The DSC investigation has revealed that SIM and ASA form a simple eutectic system containing 66.6 % w/w of SIM at the eutectic point. In vitro dissolution studies of SIM and its mixtures with ASA were carried out. The eutectic mixture shows an appreciable increase in the dissolution rate in comparison with other ratios and SIM in 0.5 % w/v sodium lauryl sulfate. The dissolution enhancement of SIM was related to the effective wetting of the drug particles with a significantly reduced size released from eutectic composition. In conclusion, dissolution of SIM can be enhanced through eutectic formation with ASA by means of simple mechanical activation (a grinding method).