• Journal of Pharmaceutical Investigation
• /
• v.29 no.2
• /
• pp.117-126
• /
• 1999

Differential scanning calorimetry(DSC) was used as a screening technique for assessing the compatibility of some drugs with excipients. On the basis of DSC results, interaction of ibuprofen with PVP K40 was found and eutectic formations with PEG 6000 or magnesium stearate were demonstrated. Fenoprofen Ca was found to interact with PEG 6000. Naproxen showed interactions with PEG 6000, PVP K40, PVPP and Mg stearate. Interactions of tiaprofenic acid with PVP K40 or PVPP were found and eutectic formations with PEG 6000 or Mg stearate were observed. Bisoprolol hemifumarate, metoprolol tartrate and penbutolol sulfate were found to interact with lactose.

• Journal of Life Science
• /
• v.28 no.4
• /
• pp.472-477
• /
• 2018

Pravastatin sodium is a 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitor used in the treatment of hypercholesterolemia by reducing cholesterol biosynthesis. Pharmaceutical excipients of commonly used including water, diluents, stabilizers, disintegrants, lubricants and colorants, and were identified for compatibility. All tests were performed by means of physical mixture of pravastatin and the excipients, which were placed in a press-through-pack (PTP) and incubated under accelerated conditions ($40^{\circ}C$ and 75% relative humidity) for 3 months. The blends of pravastatin with all excipients developed white, off white, and light brown powders, which showed no changes upon visual analysis. Accelerated conditions changed the degradation profile of pravastatin calcium in the HPLC system when mixed with different excipients. Although most excipients can have minor effects on pravastatin stability, the major degradation product from pravastatin was lactone. Low-level interaction (assay and impurity) was induced by all excipients except for microcrystalline cellulose and croscarmellose sodium. These excipients increased lactone impurity in 3 months by as much as 0.22% and 0.18% respectively. The total mixture slightly increased the lactone impurity (by 0.43% in 3 months) of pravastatin. There was no change in the assays of all excipients. These results will be helpful in studying tablet size reductions for convenience of use.

• Journal of Pharmaceutical Investigation
• /
• v.27 no.1
• /
• pp.39-49
• /
• 1997

Nicotinic acid was mixed with glass powders such as controlled pore glass (CPG), glyceryl controlled pore glass (GPG) and glass beads (GB) at room temperature. The physicochemical properties of nicotinic acid in the various mixtures were examined by differential thermal analysis, X-ray diffraction study. Infrared spectroscopy and BET gas adsorption measurements. The peak area at the melting point from the various mixtures of nicotinic acid and CPG was increased with an increase of nicotinic acid concentration while the broad peak area was remained unchanged in the DTA curve. As shown in the powder X-ray diffraction patterns, the crystalline peaks of nicotinic acid disappeared in mixture with CPG, suggesting the interaction of nicotinic acid and porous powders. It was found that the larger the content of CPG, the higher the ratio of an amorphous state to a crystalline state. BET isotherm showed that as the amount of nicotinic acid was increased, the specific surface area was reduced proportionally to nicotinic acid content of up to 40% and remained constant thereafter. Sublimation of nicotinic acid from the mixture of nicotinic acid and CPG was examined. A large quantity of nicotinic acid was retained in the mixture when stored on various temperatures in vacuo for 10 hours. The nicotinic acid mixtures with CPG or GPG showed a high dissolution rates of nicotinic acid in aqueous solution, especially in the initial dissolution stage. CPG is expected to be a good pharmaceutical excipient to reduce the crystallinity of drugs and to prevent sublimation of drugs.