stearates and butyl-stearate

The present study aimed to investigate the effects of butyl stearate on t‑butoxyl paliperidone derivative (isoperidone)‑loaded poly(lactide‑co‑glycolide) (PLGA) microspheres. The mechanism of drug release rate delay by butyl stearate was examined by accelerated testing, morphological observation, thermal and fluorescence analyses. In vivo pharmacokinetic study was conducted on female beagle dogs. Spherical microspheres with smooth surfaces, small internal pores and shell structures were initially prepared. It was found that 3% (w/w) butyl stearate prolonged the in vitro drug release period from 46 to 82 days, and in vivo release period from 20 to 27 days. Furthermore, the results demonstrated that the green fluorescence imaging of isoperidone approaching the cores of microspheres with 3% butyl stearate was brighter than in microspheres without additives. In conclusion, it was shown that butyl stearate affected the microsphere structure, isoperidone microsphere distribution and isoperidone crystallinity. The results of the present study thus provide a potential method to develop sustained‑release preparations.

Topics: Animals; Delayed-Action Preparations; Dogs; Drug Compounding; Drug Liberation; Humans; Lactic Acid; Microspheres; Paliperidone Palmitate; Particle Size; Polylactic Acid-Polyglycolic Acid Copolymer; Schizophrenia; Stearates

Microemulsions (ME) containing hexadecyltrimethylammonium bromide (HTAB)/ethanol as surfactant, isopropylmyristate (IM) or butylstearate (BS) as oil phase and aqueous buffer were studied. Pseudo-ternary phase diagrams of the investigated systems were obtained at constant surfactant/cosurfactant molar ratio (1:5) by titration in order to characterize the proportions between the components to obtain clear systems. Oil in water microemulsions were prepared in a wide range of phase volume (phi). UV-vis absorption spectra of naproxen at pH 5.5 showed that the solubility of Np increases significantly in the presence of O/W ME in high phase volumes. For both, IM and BS microemulsions, the dynamic light scattering experiments showed that the size of the oil droplets remains constant in low values of phi, increasing abruptly in high phi values. Phase solubility study revealed that for both IM and BS microemulsions, the drug incorporation followed a straight-line profile in all range of phi. The data could be analyzed through the phase-separation model and the association constants (K) calculated varied from 27 to 90 M(-1), depending on the pH and on the microemulsion oil phase.

Topics: Anti-Inflammatory Agents, Non-Steroidal; Cetrimonium; Cetrimonium Compounds; Dosage Forms; Emulsions; Ethanol; Myristates; Naproxen; Phase Transition; Stearates; Water

Topics: Heating; Lasers; Micromanipulation; Optics and Photonics; Stearates

The transfer of stearyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate from high- and low-density polyethylenes and polypropylene as well as that of n-butyl stearate from high-impact polystyrene into several foodstuffs and into different food simulants under normal storage conditions was determined radioanalytically. Additionally, the transfer of these additives into the food simulants under the standard conditions usually requested by the authorities was determined. From these figures 'correction factors' were calculated, relating the amounts of additives transferred from the plastics materials into the foodstuffs under normal conditions of storage to the transfer of these additives from the test specimens into food simulants (e.g. olive oil and HB 307) under the standard test condition of exposure at 40 degrees C for 10 days.

Topics: Butylated Hydroxytoluene; Carbon Radioisotopes; Dairy Products; Dietary Fats; Food Analysis; Food Handling; Plastics; Polyethylenes; Polypropylenes; Polystyrenes; Stearates

Topics: Acids; Dibutyl Phthalate; Dicarboxylic Acids; Oleic Acid; Oleic Acids; Stearates

Topics: Cellulose; Intestines; Stearates; Tablets, Enteric-Coated

Topics: Dibutyl Phthalate; Diffusion; Gases; Humans; Pressure; Stearates; Vapor Pressure