DEVELOPMENT AND VALIDATION OF A STABILITY-INDICATING LC METHOD FOR THE DETERMINATION OF DOMPERIDONE, SORBIC ACID, AND PROPYLPARABEN IN PHARMACEUTICAL FORMULATIONS

Embryotoxicity of silica nanoparticles in the drug delivery of domperidone in zebrafish

Domperidone is a dopamine D2 receptor inhibitor that stimulates pituitary gonadotropins. It is usually associated with synthetic GnRHa to promote spawning in fish. However, the route of administration used, intramuscular injection, can be quite stressful. Little is known about the effects of domperidone, as well as other routes. This study aims to evaluate the toxicity of domperidone encapsulated by silica nanoparticles in zebrafish embryos. The study involved four groups with three concentrations: 1. domperidone (DP) 0.0001, 0.0002 and 0.0004 mg/mL; 2. DP associated with silica nanoparticles (SiNPs) 0.0001 + 1.1, 0.0002 + 2.2 and 0.0004 + 4.4 mg/mL; 3. SiNPs 1.1, 2.2 and 4.4 mg/mL and 4. Control (E3), with four repetitions per group. Survival, teratogen and heart rate (HR) were evaluated over a period of 168 hpf. Survival was higher in DP + SiNPs treatment, HR was lower in treatment with 4.4 mg/mL of SiNPs, while treatment with 0.004 mg/mL of DP increased HR. This study demonstrated that the association of DP and SiNPs decreased the toxicity of both DP and SiNPs, demonstrating that this may be a viable alternative to reduce the possible cardiotoxic effects of DP.

Current Trends in Simultaneous Determination of Co-Administered Drugs

Recently, high demand of high-throughput analyses with high sensitivity and selectivity to molecules and drugs in different classes with different physical-chemical properties—and a reduction in analysis time—is a principal milestone for novel methodologies that researchers are trying to achieve—especially when analytical procedures are applied to clinical purposes. In addition, to avoid high doses of a single drug that could cause serious side effects, multi-drug therapies are often used to treat numerous diseases. For these reasons, the demand for methods that allow the rapid analysis of mixed compounds has increased in recent years. In order to respond to these needs, new methods and instruments have been developed. However, often the complexity of a matrix can require a long time for the preparation and processing of the samples. Different problems in terms of components, types of matrices, compounds and physical-chemical complexity are encountered when considering drugs association profiles for quantitative analyses. This review addresses not only recently optimized procedures such as chromatographic separation, but also methods that have allowed us to obtain accuracy (precision and trueness), sensitivity and selectivity in quantitative analyses for cases of drug associations.

Pressure induced transformations in sorbic acid

This research reports a pressure dependent Raman study of the sorbic acid between 0.0 and 10.0GPa. The unpolarized Raman spectra were measured in the spectral range of 20-3000cm^-1. The high-pressure Raman scattering study of the sorbic acid showed that it underwent a gradual, disordering process. At the room temperature and at the ambient pressure conditions, the crystal structure of the sorbic acid belongs to the monoclinic system with a C2/c (C_2h⁶) space group. The pressure increase induced a higher disorder in the monoclinic unit cell, since a single bending mode, and only very broad stretching Raman modes are present at pressure of ~10GPa. Upon pressure release the high-pressure phase transforms directly into the ambient-pressure phase. The presence of the internal vibrational modes is a guarantee that the molecular structure is maintained. Beyond this, the presence of external modes shows that the crystal has a memory to reverse the process and suggest that the crystal, which was in high disorder (broad Raman bands), does not suffer decomposition in the crystalline structure. The DFT calculations for the sorbic acid were performed in order to understand the vibrational properties. The theoretical study showed that the volume of the unit cell and beta angle decrease significatively when passing from the 0.0GPa to 8.0GPa. The decreases in the volume and beta angle of this particular unit cell were supposed to induce the larger increase in the bandwidths of the observed bands, pointing to some disorder in the monoclinic phase.

Temperature-dependent vibrational spectroscopic study and DFT calculations of the sorbic acid

This work reports a temperature-dependent vibrational spectroscopic study of the sorbic acid (C6H8O2), as well as the mode assignment at ambient conditions, based on the density functional theory. Temperature-dependent vibrational properties have been performed in polycrystalline sorbic acid through both Raman and infrared spectroscopy in the 20-300 K and 80-300 K temperature ranges, respectively. These studies present the occurrence of some modifications in the Raman spectra that could be interpreted as a low temperature phase transition undergone by sorbic acid from the monoclinic phase to an unknown phase with conformational change of the molecules in the unit cell.