RESUMO
This manuscript represents the view of the Dissolution Working Group of the IQ Consortium on the challenges of and recommendations on solubility measurements and development of dissolution methods for immediate release (IR) solid oral dosage forms formulated with amorphous solid dispersions. Nowadays, numerous compounds populate the industrial pipeline as promising drug candidates yet suffer from low aqueous solubility. In the oral drug product development process, solubility along with permeability is a key determinant to assure sufficient drug absorption along the intestinal tract. Formulating the drug candidate as an amorphous solid dispersion (ASD) is one potential option to address this issue. These formulations demonstrate the rapid onset of drug dissolution and can achieve supersaturated concentrations, which poses significant challenges to appropriately characterize solubility and develop quality control dissolution methods. This review strives to categorize the different dissolution and solubility challenges for ASD associated with 3 different topics: (i) definition of solubility and sink conditions for ASD dissolution, (ii) applications and development of non-sink dissolution (according to conventional definition) for ASD formulation screening and QC method development, and (iii) the advantages and disadvantages of using dissolution in detecting crystallinity in ASD formulations. Related to these challenges, successful examples of dissolution experiments in the context of control strategies are shared and may lead as an example for scientific consensus concerning dissolution testing of ASD.
Assuntos
Solubilidade , Cristalização , Liberação Controlada de FármacosRESUMO
PURPOSE: An overview of the responses to some of the most frequently asked questions regarding axitinib administration and dosage modifications used in clinical practice are presented. SUMMARY: Axitinib was approved for second-line treatment of advanced renal cell carcinoma by the Food and Drug Administration on January 27, 2012. Inquiries received over the first six months after the approval date were reviewed. A large number of questions were related to administration of axitinib in different patient populations or in patients with various comorbidities, such as its (1) use in patients unable to swallow oral medication or administration of axitinib via a nasogastric tube, (2) use in patients with renal or hepatic impairment, (3) central nervous system penetration and use in patients with brain metastases, (4) drug interactions, particularly with anticoagulants, and (5) dosage modifications. Responses to these inquiries were provided based on the published literature or from data on file from the manufacturer. The dosage of axitinib can be adjusted for use in patients with hepatic impairment or in patients who cannot otherwise tolerate the usual regimen. Patients taking concomitant warfarin can also take axitinib, and patients who cannot swallow oral medications can receive a liquid formulation of the drug, though its efficacy and comparability to the tablet formulation has not been tested. CONCLUSION: Based on the published literature and company data on file, the axitinib dosage may be modified to accommodate patients with renal or hepatic impairment, who cannot swallow oral medication, are receiving concomitant warfarin, or who cannot otherwise tolerate the standard dosage regimen. For patients who cannot swallow, an oral suspension can be prepared because crushing axitinib is not recommended.