A stability-indicating HPLC-PDA method for the determination of ferulic acid in chitosan-coated poly(lactide-co-glycolide) nanoparticles

ABSTRACT The development and validation of a simple and efficient method for the quantification of ferulic acid in poly (D,L-lactide-co-glycolide) (PLGA) nanoparticles coated with chitosan (CS) by reverse phase high performance liquid chromatography coupled to photodiode array detection was described. For the chromatographic analysis, a reverse phase C-18 column was used, mobile phase consisting of acetonitrile and 0.5% acetic acid (37:63, v/v), isocratically eluted at a flow rate of 1 mL/min. Drug determination was performed at 320 nm. The method was validated in terms of the selectivity, linearity, precision, accuracy, robustness, limits of detection and quantification. The method was linear in the range of 10 to 100 µg/mL (r=0.999) and presented limit of detection and quantification of 102 ng/mL and 310 ng/mL, respectively. The method was precise (intra and inter-day) based on relative standard deviation values (less than 3.20%). The recovery was between 101.06 and 102.10%. Robustness was demonstrated considering change in mobile phase proportion. Specificity assay showed no interference from the components of nanoparticles or from the degradation products derived from acidic and oxidative conditions. The proposed method was suitable to be applied in determining the encapsulation efficiency of ferulic acid in PLGA-CS nanoparticles and can be employed as stability indicating one.

Development and characterization of pullulan-polymethacrylate free films as potential material for enteric drug release

ABSTRACT Free films of pullulan-polymethacrylate associations were produced by casting process to develop a novel target-specific material. For characterization, tests of water vapor permeability, swelling index, infrared absorption spectroscopy, thermogravimetric analysis, scanning electron microscopy and mechanical analysis were performed. The polysaccharide concentration directly influenced vapor permeability and swelling, increasing the values of the latter up to five times when added in a proportion of 20% (per weight). The individual properties of each polymer were maintained, and chemical interactions were not detected. The films were found to be thermally stable and they had unaltered mechanical properties with the addition of the polysaccharide. The microscopic analysis revealed rugosity that was proportional to pullulan and disorganization of the polymer network at pH 6.8. These results suggest that this novel material has potential for enteric drug release because of synergism between pH and enzyme dependence.

Eudragit ® FS 30 D polymeric films containing chondroitin sulfate as candidates for use in coating seeking modified delivery of drugs

ABSTRACT Polymeric films associating different concentrations of Eudragit(r) FS 30 D (EFS) and chondroitin sulfate (CS) were produced by casting for the development of a new target-specific site material. Formed films kept a final polymer mass of 4% (w/v) in the following proportions: EFS 100:00 CS (control), EFS 95:05 CS, EFS 90:10 CS and EFS 80:20 CS. They were analyzed for physical and chemical characteristics using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and Raman spectroscopy. Furthermore, they were characterized by their water vapor permeability and degree of hydration at different conditions simulating the gastrointestinal tract. No chemical interactions were observed between CS and EFS, suggesting only a physical interaction between them in the different combinations tested. The results suggest that EFS and CS, when combined, may form films that are candidates for coating processes seeking a modified drug delivery, especially due to the synergism between pH dependency and specific biodegradability properties by the colonic microbiota. EFS 90:10 CS proved to be the most suitable for this purpose considering hydration and permeability characteristics of different associations analyzed.

Desenvolvimento e validação de método seguro e ambientalmente adequado para quantificação de atenolol em matéria prima e comprimidos / Development and validation of a safe and environmentally adequate method for the quantification of atenolol in raw material and tablets

Um dos ensaios descritos na Farmacopéia Brasileira para determinação do fármaco anti-hipertensivo atenolol como matéria prima e em comprimidos utiliza espectrofotometria ultravioleta (UV). Porém, o solvente utilizado é o metanol, um agente químico inflamável e tóxico, cujos resíduos químicos são de difícil tratamento. Portanto, é interessante o desenvolvimento de métodos analíticos que sejam mais seguros e ambientalmente adequados. Considerando que o atenolol é solúvel em soluções ácidas diluídas, foi avaliado o uso de ácido clorídrico 0,01 mol.L -1 como um método alternativo. Para isto, foi realizada a validação do novo método avaliando sua linearidade, especificidade, seletividade, intervalo, limite de quantificação e detecção, precisão, exatidão e robustez. Todas as figuras de mérito mostraram-se dentro dos limites recomendados pela Agência Nacional de Vigilância Sanitária (Anvisa). A comparação com o método original mostrou equivalência estatística entre os métodos. Assim, o método mostrou-se adequado como um procedimento mais seguro e ambientalmente adequado para as etapas de controle de qualidade relacionadas a produção de medicamentos a base de atenolol pelas indústrias farmacêuticas.

One of the tests described in the Farmacopéia Brasileira 5ª Edição (F. Bras. V) to assay the antihypertensive drug atenolol as raw material and tablets use ultraviolet spectrophotometry (UV). However, the solvent is methanol, a flammable and toxic chemical agent whose chemical residues are not easily manageable. Therefore, it is necessary to develop analytical methods that are safer and environmentally appropriate. Considering that atenolol is soluble in dilute acid solutions, the use of hydrochloric acid 0.01 mol L-1 as solvent was evaluated as an alternative method. For this, it was performed a validation of the new method assessing its linearity, specificity, selectivity, range, limit of quantification and detection, precision, accuracy and robustness. All figures of merit were within the limits recommended by the Agência Nacional de Vigilância Sanitária (ANVISA). The comparison with the original method showed statistical equivalence between the procedures. Thus, the new method was considered suitable as a safer and more environmentally appropriate for quality control of the production of drugs with atenolol by pharmaceutical industries.