ESTUDOS DA QUALIDADE DE COMPRIMIDOS E CÁPSULAS CONTENDO AMINOFILINA

Asthma is a chronic inflammatory disease characterized by impairment of the lower airways. Theophylline has been used to treat asthma and their preparation for therapeutic purposes is aminophylline. Aminophylline is a complex of theophylline and ethylenediamine, and the ethylenediamine gives an increase in aqueous solubility of theophylline. Aminophylline is often manipulated in pharmacies as capsules, even if a drug with narrow therapeutic index, which is not recommended for manipulation. A potentiometric determination should be considered in evaluating the assay of ethylenediamine. The content of ethylenediamine in reference drug is showed two times higher compared to other drugs and this may be related to the ideal dissolution profile. Generic drugs presented with the dissolution profile and dissolution efficiency data closest in relation to the reference product, which was expected. However, similar and manipulated drugs shown to be without any control of the drug release compared to the reference drug. The results show that although the requirement of ANVISA, concerning mandatory dissolution profile, the manipulated products are unsatisfactory.

Degradation kinetics of atorvastatin under stress conditions and chemical analysis by HPLC

Atorvastatin is an antilipemic drug belonging to the statins class, whose reference drug is Pfizer’s Lipitor^®. It is used to reduce the levels of lipoproteins rich in cholesterol and reduce the risk of coronary artery disease. It is well-known that calcium atorvastatin (ATV), C₆₆H₆₈CaF₂N₄O₁₀•3H₂O, presents polymorphism. The drug in question is commonly sought after by pharmaceutical industries that produce generic drugs, due to the fact that the drug has a high value price, it is consumed globally, and its patent expired in late 2010. Many questions concerning this drug’s pharmaceutical scope demonstrate its importance regarding stability studies and the identification of degradation products of drugs and pharmaceutical formulations. ATV has been found to degrade under acid and basic conditions, including a first order kinetic degradation under acid conditions, as compared to a zero order kinetic degradation under basic conditions, which tends to be less stable when studied within acid mediums. The rate constant (k) for degradation in acid medium was 1.88 × 10⁻² s⁻¹ (first order), while for basic medium k = 2.35 × 10⁻⁴ mol L⁻¹ s⁻¹ (zero order), demonstrating a lower stability of the drug within acid mediums.