Vilayat A. Sayeed

Crystallinity evaluation of tacrolimus solid dispersions by chemometric analysis

Different destructive and nondestructive analytical methods, namely powder X-ray diffractometry (PXRD), differential scanning calorimetry (DSC), Raman and near-infrared (NIR) spectroscopy and imaging, to detect and characterize tacrolimus trace crystallinity in an amorphous solid dispersion (SD) using chemometric analysis were developed. The SD was spiked with different percentages of the crystalline drug to construct an array of SDs with different crystallinity percentages. Partial least square (PLS) regression analysis was employed to compare the performance of the calibration models created using these analytical methods. The obtained results indicated a significant interaction between tacrolimus and the employed polymer and a drug dissolution dependency on the crystalline fraction within the SDs. Using two PLS factors, these analytical methods were ranked according to its specificity to detect the trace crystallinity of SDs as NIR>PXRD>Raman>DSC. Through the application of PLS, root-mean-squared error of calibration values of 2.91%, 5.36%, 7.07% and 11.58% were calculated for the calibration models constructed by NIR, PXRD, Raman and DSC, respectively. Having a prediction error of 2.1% and a correlation coefficient of 0.99, it is demonstrated that combined NIR imaging and chemometric analysis outperformed the other methods in detecting trace crystallinity in tacrolimus amorphous systems. The spatial distributions of amorphous and crystalline drug were also obtained in order to allow for studying the crystallization dissemination in the solid dispersions. Consequently, NIR and NIR imaging coupled with chemometry was shown to be a powerful tool for the prediction of drug crystallinity within SDs.

US FDA Question-Based Review for Generic Drugs: A New Pharmaceutical Quality Assessment System

The US Food and Drug Administration Office of Generic Drugs has developed a question-based review (QbR) for the Chemistry, Manufacturing, and Controls (CMC) evaluation of an abbreviated new drug application (ANDA). This new QbR system incorporates quality by design and implements risk-based assessment. It recommends that ANDAs be submitted using the Common Technical Document and include the Quality Overall Summary (QOS) that addresses all the QbR questions. The main benefits of this QbR system are to (1) assure product quality through design and performance-based specifications, (2) facilitate continuous improvement and reduce CMC supplements through risk assessment, (3) enhance the quality of reviews through standardised review questions, and (4) reduce CMC review time when applicants submit a QOS that addresses the QbR questions. The QbR was partially implemented in 2006 and is being fully implemented in 2007.

Critical factors in manufacturing multi-layer tablets—Assessing material attributes, in-process controls, manufacturing process and product performance☆

Advancement in the fields of material science, analytical methodologies, instrumentation, automation, continuous monitoring, feed forward/feed back control and comprehensive data collection have led to continual improvement of pharmaceutical tablet manufacturing technology, notably the multi-layer tablets. This review highlights the material attributes, formulation design, process parameters that impact the performance, and manufacturability of the multi-layer tablets. It also highlights on critical-to-quality elements that needs to be addressed in the regulatory submission.

Complexation of risperidone with a taste-masking resin: novel application of near infra-red and chemical imaging to evaluate complexes.

The purpose of the study was to investigate the complexation between a weakly basic drug (risperidone) and an ion exchange resin (amberlite IRP-64) used as a taste-masking agent via two preparation methods: physical mixture and solvent evaporation. Both methods were prepared in different drug-to-resin ratios by weight (1:1, 1:2, 1:4, 1:6). Physicochemical characterizations were performed using differential scanning calorimetry, x-ray diffraction, infra-red spectroscopy, Raman spectroscopy, near infra-red spectroscopy, chemical imaging and drug release studies. These physicochemical techniques revealed that risperidone formed complex with the resin via the solvent evaporation method where enhanced dissolution occurred but not with the physical mixtures.

Improvement of physicochemical properties of an antiepileptic drug by salt engineering.

The focus of the present investigation was to evaluate the feasibility of using cyclamic salt of lamotrigine in order to improve its solubility and intrinsic dissolution rate (IDR). The salt was prepared by solution crystallization method and characterized chemically by fourier transform infrared spectroscopy (FTIR), proton (1H) and carbon (13C) nuclear magnetic resonance (liquid and solid, NMR) spectroscopy, physically by powder X-ray diffraction (PXRD), thermally by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), physicochemically for solubility, IDR, solution and solid-state stability, and polymorphism by solution recrystallization and slurry conversion studies. The FTIR, NMR, PXRD, DSC, and TGA spectra and thermograms indicated the salt formation. The salt formation increased lamotrigine solubility by 19-fold and IDR by 4.9-fold in water. The solution and solid-state stability were similar to parent molecule and were resistant to polymorphic transformation. In conclusion, cyclamic salt of lamotrigine provides another potential avenue for the pharmaceutical development of lamotrigine with improved physicochemical properties especially for pediatric population. It is also possible that appropriate dosage forms can be formulated with much lower drug amount and better safety profile than existing products.

Complexation between risperidone and amberlite resin by various methods of preparation and binding study

Purpose: The purpose of this work was to investigate the effect of preparation methods and the drug-to-resin ratio on complex formation between risperidone and amberlite resin. Methods: The existence of such resin complex may provide taste-masking properties to the dosage forms. It is important to determine when and how the complex forms. Therefore, in this study, the complexes of risperidone and amberlite resin were prepared by granulation, solution, and freeze-drying methods at various drug-to-resin ratios. The physical mixtures of drug–resin were used to compare the results of complexes prepared by granulation, solution, and freeze drying. The complexes were evaluated by various methods of characterization including differential scanning calorimetry, X-ray diffraction, spectroscopy (near infrared, Fourier transform infrared, and Raman), drug release, and binding studies. Results: Complexation between risperidone and amberlite was investigated for various preparation methods. It was found that complexation occurred at lower amounts of amberlite resin (drug-to-resin ratios of 1:1 and 1:2) when solution form of drug was contacted with the resin as in the case of solution and freeze-drying techniques compared with granulation (drug-to-resin ratios of 1:4 and 1:6). Characterization studies such as differential scanning calorimetry, X-ray diffraction, spectroscopic techniques, and drug release studies differentiated complexes from the physical mixtures. Binding studies between them revealed that the binding was linear with solubility of the drug limiting the adsorption capacity. Conclusions: Results of the study highlighted the importance of the preparation methodologies to formulate complexes. When the drug and the resin were simply mixed physically, no complexation occurred. Thus, a careful evaluation of manufacturing procedure would indicate the nature and extent of complexation.

Physicochemical and mechanical properties of carbamazepine cocrystals with saccharin

The aim of present research was to investigate the physicochemical, mechanical properties, and stability characteristics of cocrystal of carbamazepine (CBZ) using saccharin (SAC) as a coformer. The cocrystals were prepared by solubility method and characterized by pH-solubility profile, intrinsic dissolution by static disk method, and surface morphology by scanning electron microscopy (SEM), crystallinity by differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD), and mechanical properties by Heckel analysis. Stability of the cocrystals were assessed by storing them at 60 °C for two weeks, 25 °C/60%RH, 40 °C/75%RH and 40 °C/94%RH for one month and compared with the stability of CBZ. The solubility profile of cocrystal was similar to CBZ. The cocrystal and CBZ have shown the same stability profile at all the conditions of studies except at 40 °C/94%RH. Unlike the CBZ, cocrystal was stable against dihydrate transformation. The compacts of cocrystal have a greater tensile strength and more compressibility. The Heckel analysis suggested that plastic deformation started at low compression pressure in the cocrystal than CBZ. In summary, the cocrystal form of carbamazepine provides another avenue for product development which is more stable than the parent drug.

Difference in the Lubrication Efficiency of Bovine and Vegetable-Derived Magnesium Stearate During Tabletting

The purpose of this work was to evaluate and compare the functionality of bovine fatty acids-derived (MgSt-B) and vegetable fatty acids-derived (MgSt-V) magnesium stearate powders when used for the lubrication of granules prepared by high-shear (HSG) and fluid bed (FBG) wet granulation methods. The work included evaluation of tablet compression and ejection forces during tabletting and dissolution testing of the compressed tablets. Granules prepared by both granulation methods required significantly lower ejection force (p < 0.01) when lubricated with the MgSt-V powder as compared to those lubricated with the MgSt-B powder. Granules prepared by the HSG method and lubricated with the MgSt-V powder also required significantly lower compression force (p < 0.01) to produce tablets of similar weight and hardness as compared to those lubricated with the MgSt-B powder. The dissolution profiles were not affected by these differences and were the same for tablets prepared by same granulation method and lubricated with either magnesium stearate powder. The results indicate significant differences (p < 0.01) between lubrication efficiency of the MgSt-B and the MgSt-V powders and emphasize the importance of functionality testing of the MgSt powders to understand the impact of these differences.

Functionality of magnesium stearate derived from bovine and vegetable sources: dry granulated tablets.

Magnesium stearate is a functional excipient used to ensure efficient ejection of tablets. This study compares the functionality of a vegetable and bovine grade of magnesium stearate. Tablets were prepared by direct compression and dry granulation of a model formulation. Physical and chemical tests were performed on bulk powders, granule intermediates, and finished tablets to provide a comprehensive comparison of the two grades of magnesium stearates. Raw material characterization of the two grades showed no difference in particle size, surface area, true density, and total moisture content. However, significant differences in fatty acid composition, surface tension, and zeta potential were detected. Tablet ejection force for the physical mixture formulations was variable, showing similar ejection force for the two grades of magnesium stearate at some concentrations and different ejection forces at other concentrations. The dry granulated formulation containing vegetable-based magnesium stearate showed a lower ejection force than the formulation containing bovine-based magnesium stearate. There was no difference between the dissolution profiles of the tablets containing the two grades of magnesium stearate prepared by both methods. The results indicated that magnesium stearate interchangeability with respect to lubricant efficiency depends upon the level in which it is used and the manufacturing method.

Process Analytical Technology to Understand the Disintegration Behavior of Alendronate Sodium Tablets

Various adverse events including esophagus irritations have been reported with the use of alendronate tablets, likely attributed to the rapid tablet disintegration in the mouth or esophagus. Accordingly, the disintegration of six alendronate tablet drug products was studied using a newly developed testing device equipped with in-line sensors, in addition to the official compendial procedure for measuring the disintegration time. The in-line sensors were used to monitor the particle count and solution pH change to assess the onset and duration of disintegration. A relatively large variation was observed in the disintegration time of the tested drug products using the compendial method. The data collected using the in-line sensors suggested that all tested drug products exhibited almost instantaneous onset of disintegration, under 2 s, and a sharp drop in solution pH. The drop in pH was slower for tablets with slower disintegration. The in-house prepared alendronate test tablets also showed similar trends suggesting rapid solubilization of the drug contributed to the fast tablet disintegration. This research highlights the usefulness of the newly developed in-line analytical method in combination with the compendial method in providing a better understanding of the disintegration and the accompanying drug solubilization processes for fast disintegrating tablet drug products.