The evaluation of coated granules to mask the bitter taste of dihydroartemisinin / A avaliação de grânulos revestidos para mascarar o sabor amargo da diidroartemisina

The purpose of this study was to mask the bitter taste imparted by dihydroartemisinin (DHA) by the use of different coating materials. Trial-1 and trial-2 were conducted to prepare the DHA granules. The granules produced from trial-1 were irregular in shape and smaller in size while the trial-2 granules were more regular and larger in size. The granules obtained from both trials were then coated with two different coating methods, namely A and B, depending upon coating material. The trial-2 granules showed better flow properties than trial-1 granules. In vitro dissolution studies in phosphate buffer at pH 6.8 revealed that granules of trial-2B released only 34 percent ± 3 DHA in two minutes compared with trial-1A (57 percent ± 2), trial-1B (48 percent ± 2) and trial-2A (53 percent ± 7). The pleasant taste perception (PTP) test also confirmed the taste masking efficacy of trial-2B (P < 0.05). Scanning electron microscopy (SEM) revealed the more regular and smooth surface of trial-2B granules. In addition, the differential thermal and thermogravimetric analysis (TG-DTA) confirmed no interaction between the materials and pure DHA. DHA has shown its characteristic peaks in the x-ray diffraction (XRD) patterns which were also prominent in all the granules. In conclusion, the granules obtained from trial-2B displayed considerable decrease in the bitter taste of DHA thereby fulfilling the purpose of this study.

O objetivo deste estudo foi o de mascarar o gosto amargo característico da diidroartemisinina (DHA) pelo uso de diferentes materiais de revestimento. Experimento-1 e experimento-2 foram realizados para preparar grânulos de DHA. Os grânulos produzidos pelo experimento-1 mostraram-se irregulares e menores se comparados aos obtidos pelo experimento-2, que foram mais regulares e maiores. Os grânulos obtidos em ambos os experimentos foram, então, revestidos por dois métodos distintos de revestimento, designados como A e B, dependendo do material de revestimento empregado. Os grânulos do experimento-2 mostraram melhor propriedade de fluxo que os obtidos no experimento-1. Estudos de dissolução in vitro em tampão fosfato pH 6,8 revelaram que grânulos do experimento-2B liberaram apenas 34 por cento ± 3 da DHA em dois minutos se comparado com experimento-1A (57 por cento ± 2), experimento-1B (48 por cento ± 2) e experimento-2A (53 por cento ± 7). A Análise Sensorial quanto ao sabor (Pleasant Taste Perception - PTP) também confirmou a eficácia do experimento-2B (P <0,05) em mascarar o gosto amargo da DHA. Microscopia Eletrônica de Varredura (SEM) revelou a superfície mais regular e lisa dos grânulos obtidos pelo experimento-2B. Além disso, Análise Termogravimétrica e Análise Térmica Diferencial (TG-DTA) confirmaram que não há nenhuma interação entre os materiais e a DHA pura. DHA mostrou seus picos característicos na Difração de Raios X (XRD) em padrões que também foram proeminentes em todas as amostras. Em conclusão, os grânulos obtidos pelo experimento-2B exibiram diminuição considerável no gosto amargo da DHA, o que era o propósito deste estudo.

Praziquantel-polyethylene glycol 4000 solid dispersions enhancing drug dissolution rate and schistosomicidal activity

Praziquantel [PZQ] solid dispersions [SDs] with polyethylene glycol 4000 [PEG 4000] were prepared by the co-evaporation method using absolute ethanol. Different drug: polymer ratios viz., 90:10 [10% SD], 80:20 [20% SD], 70:30 [30% SD] and 20% physical mixture [PM] were used and the prepared SDs as well as the drug were evaluated through differential scanning calorimetry [DSC], X-ray diffraction [XRD], dissolution, ex-vivo and in-vivo studies. The results revealed that the improvement achieved in physical properties of the drug, via SD, affected its dissolution rate in 0.1N HCI, pH: 1.2 where the 20% SD showed maximum enhancement of dissolution rate compared to all other systems. In addition, ex-vivo and in-vivo studies revealed higher efficacy of the 20% SD system in reducing worm burden, ova count and granuloma count and diameter, in mice infected with S. mansoni, compared to free PZQ. Finally we conclude that the 20% SD of PZQ with PEG 4000, bearing 80% PZQ, instead of 100% in the free state, could be used as an oral alternative to free PZQ, yielding better absorption and schistosomicidal activity against S. mansoni, with reduced side effects