SYNTHESIS AND CHARACTERIZATION OF n-BUTYL 4-(3,4-DIMETHOXYPHENYL)-6-METHYL-2-THIOXO-1,2,3,4 TETRAHYDROPYRIMIDINE-5-CARBOXYLATE NANOCRYSTALLINE PARTICLES BY WATER/OIL MICROEMULSION METHOD

Abstract

Various pyrimidine derivatives are well known for their different pharmaceutical applications. The n-butyl 4-(3, 4-dimethoxyphenyl)-6-methyl-2-thioxo-1,2,3,4 tetrahydropyrimidine-5-carboxylate (n-butyl THPM) was synthesized by using n-butylacetoacetate. The n-butyl acetoacetate was obtained by transesterification of ethyl acetoacetate with n-butyl alcohol using Biginelli condensation. The synthesized powder was used to obtain the nanoparticles of n-butyl THPM by using water/oil microemulsion technique. The average particle size was calculated from the powder XRD pattern by applying Scherrer's formula. The nanoparticles of n-butyl THPM were observed by Transmission Electron Microscope (TEM). The diameter of the nanoparticles varied from 15 nm to 65 nm. The nanoparticles were also characterized by FT–IR spectroscopy, TG–DTA–DSC and mass spectroscopy. The n-butyl THPM nanoparticles were stable up to 280°C. Thermodynamic and kinetic parameters of decomposition were obtained by applying Coats and Redfern relation to the thermogram. The dielectric study was carried out in the frequency range of 50 Hz to 5 MHz. The dielectric constant, dielectric loss and ac conductivity decreased as the frequency of applied field increased.

Opportunities, Challenges and Pathways of Nano-Medicines: A Concise Review

“…Reducing the particle size of an API (Active Pharmaceutical Ingredient) is an efficient and reliable technique of improving the bioavailability of relatively insoluble drug that is often limited by poor dissolution rate. Recently, some attempts have been made to develop the nano crystalline API using micro-emulsion technique and compared the physical properties with the bulk materials, for example, n-butyl 4-(3, 4-dimethoxyphenyl) -6-methyl-2thioxo-1,2,3,4 etrahydropyrimidine-5-carboxylate [3]. The nanostructures are expected to give the advantages such as increased rate of absorption, reduction in the required dose, reduction in the fed/ fasted variability, improved dose proportionality, smaller dosage forms, rapid formulation development and possible application to all route of administration and any dosage form [2,4].…”