Ibuprofen-wax

For instance, when the chemical stability of a suspension of ibuprofen powder and other ibuprofen-wax microspheres was studied with a modified HPLC procedure for three months, the amount of drug released from the microspheres was affected by the medium pH, type of suspending agent, and storage temperature without observing chemical degradation of the drug [49]. 

Adeyeye, C. M., and Price, J. C. (1997), Chemical dissolution stability and microscopic evaluation of suspensions of ibuprofen and sustained release ibuprofen-wax microspheres, /. Microencapsul., 14(3), 357-377. 

Adeyeye, C.M. Price, J.C. Development and evaluation of sustained-release ibuprofen-wax microspheres. II. In vitro dissolution studies. Pharm. Res. 1994, 11, 575-579. 

How much of a crystallizable material X can I blend uniformly into a polymer until it starts to form crystals A series of blends with increasing amount of X is prepared. The samples are studied by WAXS (cf. Sect. 8.2) using laboratory equipment. Crystalline reflections of X are observed, as X starts to crystallize. Peak areas can be plotted vs. the known concentration in order to determine the saturation limit. Think of X being Ibuprofen and Y a polystyrene-(7 )-polyisoprene copolymer, and you have an anti-rheumatism plaster. 

Zhou, F. Vervaet, C. Schelkens, M. Lefebvre, R. Remon, J.P. Bioavailability of ibuprofen from matrix pellets based on the combination of waxes and starch derivatives. Int. J. Pharm. 1998, 168, 79-84. 

Fig. 4 Ibuprofen release from different wax microparticles (actual drug loading) ( ) Precirol AT05 (35.3%), ( ) Gelucire 64/02 (35.4%), (. ) beeswax (37.7%), (A) carnauba wax (37.3%), (0) paraffin wax (35.0%). (From Ref. f)...

De Brabander C, Vervaet C, Gortz JP, et al. Bioavailability of ibuprofen from matrix minitablets based on a mixture of starch and microcrystalline wax. Int J Pharm 2000 208 81-86. 

Kamble, R., Maheshwari, M., Paradkar, A., and S. Kadam. Melt solidification technique Incorporation of higher wax content in ibuprofen beads. AAPS Pharm Sci Technol, 5(4) (2004) 75-83. 

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