Avaliação da funcionalidade dos excipientes de cápsulas de furosemida manipuladas nas farmácias de Manaus/AM

Abstract

Oral administration and absorption of drugs depend essentially on the aqueous solubility and intestinal permeability of the molecule, which are key parameters for bioavailability and therapeutic efficacy. The excipients exert well-established roles in the composition of the medicaments, which may increase the stability, solubility, absorption and efficacy of the drug. Consequently, the inappropriate use of an excipient may impact the biopharmaceutical stage, especially in its solubilization and permeation, which will reflect in the pharmacokinetic stage. The Biopharmaceutical Classification System (BCS), based on the properties of solubility and permeability, is a tool that emerged in the 1990s to help predict the bioavailability of the drugs. BCS classifies the drug into four categories, where Class I drugs have high solubility and permeability, while Class IV drugs have low solubility and permeability. Furosemide is classified, according to BCS, as a Class IV drug and, therefore, is a substance of difficult solubilization and permeation. In vitro dissolution studies allow the dissolution profile of the drug to be evaluated by simulation of physiological conditions of the gastrointestinal tract (GIT) to determine its release or release rate kinetics, which are fundamental for the evaluation of pharmaceutical equivalence between different manufacturers of the same product. And in order to estimate whether there is truthfulness in the use of standard excipients for drug formulation, as well as whether or not the size of the capsule influences the dissolution of the drug, furosemide capsules number 2 and 4 were manipulated using the excipients recommended by the literature, and later compared to formulations of pharmacies. In this sense, the present study evaluated, by means of in vitro pharmacopoeial tests that determine the drug's drug availability, if the manipulation pharmacies of Manaus used the excipients proposed by the technical and scientific literature that guarantee the dissolution of manipulated furosemide in capsules, as well as the quality parameters for oral solid dosage forms. Not all pharmacies have met the minimum quality requirements recommended by pharmacopoeias. To assess drug release, dissolution profiles of furosemide were plotted in phosphate buffer pH 5.8. The results obtained indicated significant differences in the rate and amount of furosemide released, and only 1 pharmacy was approved in the dissolution test in the second stage, and capsule number 2 is the most indicated. Thus, it was found that for the biopharmaceutical factors of furosemide to be improved, it is necessary to add suitable excipients, and that they exert substantial influence on the rate of drug release. The inappropriate use of its excipients affect the solubility and permeability and, therefore, its bioavailability, impairing the clinical response and treatment of the patient.