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ABSTRACT

Purpose: To obtain quercetin-isonicotinamide co-crystal (CQINA) with improved physicochemical and in-vitro dissolution characteristics. Methods: Co-crystallization of quercetin (Q) and isonicotinamide (INA) in molar ratio of 1:1 was performed using solvent evaporation method with the addition of 50 mL of ethanol (99.9%, v/v). The resultant solution was thoroughly mixed and stirred at room temperature for 48 h to slowly evaporate the solvent until CQINA was obtained. The co-crystal phase was characterized using differential scanning calorimetry (DSC), powder x-ray diffractometry (PXRD), scanning electron microscopy (SEM), and fourier transform infrared (FTIR) spectroscopy. In-vitro dissolution was performed by USP method II in 900 mL citrate buffer (pH 5.0 ± 0.05), with stirring at 100 rpm and at 37 ± 0.5 °C. Results: Computational approach predicted the formation of hydrogen bonds between Q and coformers used, and the interaction involved minimum energy. In CQINA thermogram, a new endothermic peak was formed with a melting point of 255.26 °C, while Q (314.85 °C) and INA (156.62 °C). Images from DSC, PXRD, SEM and FTIR showed that the crystal habits and morphologies of the CQINA differed from those of the original components. There was an improvement in the dissolution profile of CQINA, when compared with those of the original components. Conclusion: Q and INA subjected to solvent evaporation result in the formation of a CQINA with different crystal habit, which possess physicochemical characteristics different from those of its constituents. Modification of Q crystals in CQINA increases its in vitro dissolution, making it a potential pharmaceutical agent.

This study aimed to improve the solubility of quercetin by solvent pH control method and crystal modification through co-crystal formation using isonicotinamide as its co-former. Solubility of quercetin was tested at nine pH levels using phosphate buffer solvents. Quercetin-isonicotinamide co-crystal was prepared by a solvent evaporation method. Co-crystal preparation was carried out using two different stoichiometric ratios of quercetin-isonicotinamide (1:1 and 1:3). The co-crystalline solubility test was performed in 50 mL citrate buffer (pH 5.0 ± 0.05) at a temperature of 37 ± 0.5C. The thermodynamic parameters of quercetin and co-crystal were analyzed to determine the mechanism of the quercetin solubility process. Increasing the pH of solvents has proven to increase the solubility of quercetin. The quercetin oxidation reaction starts at pH level of 7.4. The formation of quercetin-isonicotinamide co-crystal at ratio of 1:1 and 1:3 shows the increase of quercetin solubility by 1.36 and 1.27 times, respectively. The thermodynamic parameters of the quercetin and quercetinco-crystal, which include entropy, enthalpy, and free energy values, can be used to explain the solubility process of quercetin. Quercetin has increased solubility under alkaline pH conditions, but undergoes an oxidation reaction at pH 7.4 and easily oxidized at alkaline pH. Crystal modification of quercetin by the co-crystal formation method has proven to increase the solubility of quercetin so that it can be used for the development of quercetin as a candidate for effective, safe, and acceptable active pharmaceutical ingredient.

The use of cassava starch for excipient in the manufacturing of the tablet has some problems, especially on physical-mechanical properties. The purpose of this study was to determine the effect of various temperature and pH in the process of modification on the physical-mechanical properties of modified cassava starch. Modifications were performed by suspending cassava starch into a solution of 3 % (w/v) PVP K30. The effect of various temperatures was observed at temperatures of 25; 45 and 65 C, while the effect of various pH was observed at pH of 4.0; 7.0 and 12.0. The results showed that the temperature and pH did not affect the physical-mechanical properties of the modified cassava starch. Modification of cassava starch at pH and temperature of 7.0 and 45 C was produced modified cassava starch with the most excellent solubility, while the best swelling power were formed by the modification process at pH and temperature of 7.0 and 25 C. Overall, the most excellent compression properties of modified cassava starch resulted from the modification process at pH 12. ABSTRAKPenggunaan pati singkong untuk bahan tambahan pada pembuatan tablet mempunyai permasalahan sifat mekanik-fisik. Tujuan dari penelitian ini adalah untuk mengetahui pengaruh perbedaan suhu dan pH pada proses modifikasi terhadap sifat mekanik-fisik pati singkong termodifikasi yang dihasilkan. Modifikasi dilakukan dengan mensuspensikan pati singkong dalam larutan PVP K3 0,3 %. Pengaruh suhu diamati pada perlakuan suhu 25; 45 dan 65 C sedangkan pengaruh pH diamati pada perlakuan pH 4,0; 7,0 dan 12,0. Hasil penelitian menunjukkan bahwa suhu dan pH tidak mempengaruhi sifat mekanik-fisik pati singkong termodifikasi. Modifikasi pati singkong pada pH 7,0 dan suhu 45 C menghasilkan pati singkong termodifikasi dengan kelarutan paling baik, sedangkan daya mengembang paling besar dihasilkan proses modifikasi pada pH 7,0 dan suhu 25 C. Sifat kompresi paling baik dari pati singkong termodifikasi dihasilkan dari proses modifikasi pada pH 12.Kata kunci: modifikasi, pati singkong, pengaruh suhu-pH, sifat kompresi.

Kayu secang (Caesalpinia sappan L.) dilaporkan memiliki sifat antioksidan alami. Brazillin merupakan salah satu kandungan senyawanya yang berkhasiat sebagai antioksidan. Antioksidan dapat digunakan untuk mencegah penuaan dini pada kulit. Essence adalah salah satu kosmetik yang mengandung antioksidan topikal. Essence memiliki keunggulan dibandingkan produk perawatan kulit lainnya dan essence lebih mudah menyerap ke dalam kulit. Tujuan penelitian ini adalah untuk mengoptimalkan dan mengevaluasi essence ekstrak etanol kayu secang sebagai antioksidan topikal. Simplex lattice design digunakan untuk mengevaluasi pengaruh konsentrasi butilen glikol dan gliserin pada karakteristik essence. Metode yang digunakan dalam ekstraksi adalah maserasi dengan pelarut etanol. Hasil penelitian menunjukkan bahwa butilen glikol dan gliserin dapat meningkatkan viskositas dan nilai pH essence. Formula essence optimum terdiri dari 10% butilen glikol dengan prediksi nilai viskositas 2,944 dPas dan pH 5,075. Formula optimum essence ekstrak kayu secang memiliki tekstur kental, bau khas ekstrak, berwarna kuning kecoklatan, homogen, dan memiliki daya sebar 14 cm.

Introduction: Ibuprofen is a non-steriodal anti-inflammatory drug which shows low bioavailability. For gel preparations it is important to increase the release rate of ibuprofen by using solid dispersion systems. Objective: To obtain the optimum release rate of ibuprofen-PEG 6000 solid dispersion from gel, by optimising the gelling agent and the penetrating enhancers. Method: Determination of gelling agent was carried out by comparing the ibuprofen release flux. The gel formulation with the best release flux will be used in the determination of penetrating enhancer to obtain the optimum release flux, by using a two-factor factorial design. Result: HPMC showed the highest release flux (339.5 g/cm2min). The results showed an increase in the release flux (489.4 g/cm2min) in the optimum formula with 39.9% propylene glycol and 3.3% isopropyl myristate. Conclusion: The increase in the ibuprofen solid dispersion release flux has been carried out using HPMC, and propylene glycol-isopropyl myristate as a penetrating enhancer.

Atorvastatin calcium is a cholesterol-lowering drug that is very potent but difficult to dissolve in water, so its bioavailability is low. In this study, atorvastatin calcium-dipicolinic acid multicomponent solids were prepared using the liquid-assisted grinding method to improve atorvastatin calcium's solubility. Characterization of multicomponent solids was carried out using powder x-ray diffraction (PXRD), differential scanning calorimetry (DSC), fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Solubility test was carried out by shaking method using distilled water media. The results showed that the particles of atorvastatin calcium - dipicolinic acid multicomponent solids had an irregular shape with rough and porous surface topography. The multicomponent solids have a diffractogram with specific peaks of 2θ at 8.8, 9.9, 11.5, 16.7, 19.1, 21.2, 22.4, 23.4, and 27.7°. The DSC thermogram of multicomponent solids showed a sharp endothermic peak at 181.9 °C (∆H=17.69 J/g), indicating its melting point. The FTIR spectra of atorvastatin calcium-dipicolinic acid multicomponent solids indicated an intermolecular interaction that was thought to be a hydrogen bond between the molecules of atorvastatin calcium and dipicolinic acid. The results of the solubility test showed that the atorvastatin calcium-dipicolinic acid multicomponent solids had a significantly increased solubility (p<0.05) compared to the solubility of pure atorvastatin calcium.