Preparation and Characterization of Solid Dispersions of Artemether by Freeze-Dried Method

Abstract

Solid dispersions of artemether and polyethylene glycol 6000 (PEG6000) were prepared in ratio 12 : 88 (group-1). Self-emulsified solid dispersions of artemether were prepared by using polyethylene glycol 6000, Cremophor-A25, olive oil, Transcutol, and hydroxypropyl methylcellulose (HPMC) in ratio 12 : 75 : 5 : 4 : 2 : 2, respectively (group-2). In third group, only Cremophor-A25 was replaced with Poloxamer 188 compared to group-2. The solid dispersions and self-emulsified solid dispersions were prepared by physical and freeze dried methods, respectively. All samples were characterized by X-ray diffraction, attenuated total reflectance Fourier transform infrared spectroscopy, differential scanning calorimeter, scanning electron microscopy, and solubility, dissolution, and stability studies. X-ray diffraction pattern revealed artemether complete crystalline, whereas physical mixture and freeze-dried mixture of all three groups showed reduced peak intensities. In attenuated total reflectance Fourier transform infrared spectroscopy spectra, C–H stretching vibrations of artemether were masked in all prepared samples, while C–H stretching vibrations were representative of polyethylene glycol 6000, Cremophor-A25, and Poloxamer 188. Differential scanning calorimetry showed decreased melting endotherm and increased enthalpy change (ΔH) in both physical mixture and freeze-dried mixtures of all groups. Scanning electron microscopy of freeze-dried mixtures of all samples showed glassy appearance, size reduction, and embedment, while their physical mixture showed size reduction and embedment of artemether by excipients. In group-1, solubility was improved up to 15 times, whereas group-2 showed up to 121 times increase but, in group-3, when Poloxamer 188 was used instead of Cremophor-A25, solubility of freeze-dried mixtures was increased up to 135 times. In fasted state simulated gastric fluid at pH 1.6, the dissolution of physical mixture was increased up to 12 times and freeze-dried mixtures up to 15 times. The stability of artemether was substantially enhanced in freeze-dried mixtures by using polyethylene glycol 6000, Cremophor-A25, and Poloxamer 188 of self-emulsified solid dispersions of artemether in Hank's balanced salt solution at pH 7.4.

Sesquiterpene Lactones fromArtemisiaGenus: Biological Activities and Methods of Analysis

“…In the case of IR spectra, the common elements are attributed to stretching vibrations of C=O (1420–1300 cm −1 ), C–O (1380–1370 cm −1 , 1235 cm −1 , and 1093 cm −1 ), C–O–O–C (890–820 cm −1 , 1121.62 cm −1 ), O–O (825 cm −1 ), C–O–C (1023.89 cm −1 and 1277.83 cm −1 ), C–H bending vibrations (1225–950 cm −1 ), C–H stretching vibrations (2844.99, 2873.61, 2914.58, and 2936.97 cm −1 ), rocking vibration of CH 2 (700 cm −1 ) and CH 3 (2947 cm −1 ), and aromatic ring vibrations (1650–1400 cm −1 and 2000–1620 cm −1 ) [ 121 , 148 , 149 ].…”

Impact of processing methods on the dissolution of artemether from two non-ordered mesoporous silicas

“…The resultant freeze-dried mixtures were gently triturated and then passed through a sieve no. 60 before storing in airtight containers (Ansari et al, 2015).…”

Artemether-Loaded Zein Nanoparticles: An Innovative Intravenous Dosage Form for the Management of Severe Malaria

“…The FTIR spectra of raw artemether, artemether-loaded zein nanoparticles, sodium caseinate, zein and their physical mixture (mass ratio of 1:5:5) are shown in Figure 7 c. Characteristic artemether bands were recorded at 2937, 1455 and 1036 cm −1 , representative of C-H stretching, C-H bending and C-O-C stretching vibrations, respectively [ 23 ]. The FTIR spectra of artemether-loaded zein nanoparticles showed peaks at 2947 (C-H stretching vibration), 1450 (C-H bending vibration) and 1034 cm −1 (C-O-C stretching vibration).…”