Physicochemical characterization of oxyphenbutazone and solid-state stability of its amorphous form under various temperature and humidity conditions.

Investigation of the Effects of Pharmaceutical Processing Upon Solid-State NMR Relaxation Times and Implications to Solid-State Formulation Stability

“…The flow rate was 10-12 mL/min, and the inlet and outlet temperatures were 172-1748C and 95-1008C, respectively. Lyophilization was performed using a VirTis AdVantage benchtop lyophilizer (Gardiner, NY) from $10 mL aliquots of the above solution using the following recipe: (i) freezing at À358C for 2 h; (ii) primary drying at À358C for 10 h; (iii) secondary drying at À15, À5, 5, 15, 20, and 258C, for 10,8,6,6,12, and 10 h, respectively. 16 Tablets 7 mm in diameter were prepared by compressing powdered lactose at $5000 psi, static for 10 s. Cryogrinding was performed using a SPEX CertiPrep 6750 Freezer/Mill (SPEX CertiPrep, Inc., Metuchen, NJ) with $2 g bulk material loaded into the grinding vial for each experiment.…”

“…[4][5][6][7] The higher-energy amorphous state is metastable relative to its crystalline counterparts, and thus is prone to changes in physical properties such as water uptake and recrystallization. 2,[8][9][10] The greater mobility inherent in amorphous materials allows for greater reactivity and faster degradation. 4,[11][12][13] For these reasons, among others, the ability to characterize and quantify the amorphous phase, especially small amounts of it in solid-state dosage forms, is important to the pharmaceutical industry.…”

Polymorphism of Sulindac: Isolation and Characterization of a New Polymorph and Three New Solvates

“…The ability of a drug to form solvates can greatly increase the number of available possibilities for modifying and controlling processing, dissolution, stability, and bioavailability. 1 The polymorphism of nonsteroidal antiinflammatory drugs (e.g., aspirin, 2-4 phenylbutazone, 5-8 indomethacin, [9][10][11][12] mefenamic acid, 13 flufenamic acid, [14][15] benoxaprofen, 16 diflunisal, [17][18] oxyphenbutazone, 19 piroxicam, [20][21][22][23][24] and tenoxicam 25 ) has been extensively investigated. Solvates have been described for phenylbutazone in isobutanol and cyclohexane, 26 indomethacin in benzene, 27 oxyphenbutazone in benzene and cyclohexane, 28 and tenoxicam in acetonitrile.…”

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“…Optical microscopy: Although dissolution rate for poorly water-soluble drug can be enhanced by converting the drug into its amorphous form 31 but it can be thermodynamically unstable, and under certain levels of heat and humidity, could recrystallize into a more stable, poorly water-soluble form 32 . Among the formulations tested, CBZ crystallized out of the formulations from poloxamer containing solid dispersions (Fig.…”