Résumé
Arsenic contamination in groundwater is a global health challenge. A large number of people worldwide are affected by arsenic poisoning. Paracetamol is a widely used analgesic-antipyretic drug. Effect of arsenic on paracetamol binding to protein has been investigated using two site specific probes and equilibrium dialysis method was used for the experiment. In absence of any site specific probes free concentration of paracetamol bound to bovine serum albumin increased from 3.95 ± 1.164% to 25.36 ± 1.164%. In presence of site-I specific probe warfarin sodium the % release of drug was steady at around 14%. But in presence of site-II specific probe an increment of free drug concen-tration was observed from 14.38 ± 1.164% to 54.72 ± 1.552%. Thus it can be assumed that the free concentration of paracetamol was increased to a greater extent in presence of arsenic and probably arsenic bound to site-II of BSA. Thus arsenic may displace paracetamol by binding with high affinity binding site, site-II in the BSA and probably arsenic has little effect to site-I.
Résumé
Arsenic contamination in groundwater is a global health challenge. A large number of people worldwide are affected by arsenic poisoning. Paracetamol is a widely used analgesic-antipyretic drug. Effect of arsenic on paracetamol binding to protein has been investigated using two site specific probes and equilibrium dialysis method was used for the experiment. In absence of any site specific probes free concentration of paracetamol bound to bovine serum albumin increased from 3.95 ± 1.164% to 25.36 ± 1.164%. In presence of site-I specific probe warfarin sodium the % release of drug was steady at around 14%. But in presence of site-II specific probe an increment of free drug concen-tration was observed from 14.38 ± 1.164% to 54.72 ± 1.552%. Thus it can be assumed that the free concentration of paracetamol was increased to a greater extent in presence of arsenic and probably arsenic bound to site-II of BSA. Thus arsenic may displace paracetamol by binding with high affinity binding site, site-II in the BSA and probably arsenic has little effect to site-I.
Résumé
Improving oral bioavailability of drugs those given as solid dosage forms remains a challenge for the formulation scientists due to solubility problems. Most of the newly invented chemical entities are poorly water soluble. As a result formulating them as oral solid dosage forms is a hurdle to the specialists. Many techniques have been exercised to improve oral bioavailability of drugs. Among several methods, solid dispersion has attracted attention of the researchers for previous 50 years. Different formulation strategies have been taken to prepare solid dispersions. It is evident that solid dispersions improve solubility of drug particles thus enhancing dissolution characteristics of drugs they increase the oral bioavailability. This review paper will focus on different aspects of solid dispersion preparation; their advantages, major challenges and preparation methods.