PubMed · 14300999
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D E WURSTER, P W TAYLOR. 1965. DISSOLUTION RATES.. https://doi.org/10.1002/jps.2600540202
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Techniques of thermal and isothermal stress testing (IST) were used to evaluate the compatibility of isosorbide mononitrate (IMN) with selected excipients used in the development of extended release formulations. In the first phase of the study, differential scanning calorimeter (DSC) was used as a tool to detect any interaction. In the next phase, excipients defined in the prototype formula were tested for their compatibility with IMN using IST. Based on the results, cellulose acetate and MCC were found to show interaction with IMN. Results of IST demonstrated incompatibility between IMN and cellulose acetate. All the excipients defined in the prototype formula were found to be compatible with IMN. Using the excipients that were found to be compatible with IMN, formulations were optimized. The optimized formulation was found to be stable after 3 months of storage at accelerated stability conditions (40 degrees C and 75% RH). In conclusion, tools of DSC, and IST were successfully employed to evaluate the compatibility of IMN with selected excipients.
A stability-indicating high performance liquid chromatographic (HPLC) method was developed for the assay of glucosamine in bulk forms and solid dosage formulations. The HPLC separation was achieved on a Phenomenex Luna amino column (150 mm x 4.6 mm, i.d., 5 microm particle size) using a mobile phase of acetonitrile-phosphate buffer (75:25, v/v, pH 7.50) at a flow rate of 1.5 ml min(-1) and UV detection at 195 nm. The method was validated for specificity, linearity, solution stability, accuracy, precision, limit of detection, and limit of quantitation. The detector response for glucosamine hydrochloride was linear over the selected concentration range from 1.88 to 5.62 mg ml(-1) with a correlation coefficient 0.9998. The accuracy was between 98.9 and 100.5%. The precision (R.S.D.) amongst six sample preparations was 1.1%. The limit of detection and the limit of quantitation are 0.037 and 0.149 mg ml(-1), respectively. The sample and standard solutions were stable for 1 week. The method was successfully used for analysis of active-excipient compatibility samples used for development of a solid dosage formulation in our laboratory and subsequent stability studies. The method was also used for the analysis of glucosamine in several commercially available solid dosage forms.
Processing-induced transformations in drug formulation may induce adverse biopharmaceutical changes in the finished product. During the drying phase of wet granulation, theophylline monohydrate transforms either the stable (form I), or a polymorphic, metastable (form I(*)) form of anhydrous theophylline. We investigated the effect of two drying methods (multichamber microscale fluid bed dryer MMFD) or variable temperature X-ray powder diffractometer (VT-XRPD) on the relative amounts of the different theophylline forms remaining in the dried granules. Granules were analyzed using XRPD and near-infrared spectroscopy. Form I(*) was the predominant form of theophylline after drying at 40-50 degrees C with both drying techniques. Although drying at temperatures over 50 degrees C produced mostly form I, more than 20% of form I(*) remained even at 90 degrees C when drying in MMFD. In these conditions, humidity had little influence on the amount of form I(*) in the granules. In contrast, drying in a VT-XRPD at 60 degrees C produced form I already during the first 15min. Using additional drying methods, including MMFD, during the preformulation stage can be more informative about the possible polymorphic transformations and their underlying mechanisms, such as triboelectrification or recrystallization, in drug ingredients during the manufacturing process.