Structural Properties of Polyethylene Glycol-Polysorbate 80 Mixture, a Solid Dispersion Vehicle

We evaluated the bioavailability, liver distribution, and efficacy of silymarin-D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) solid dispersion (silymarin-SD) in rats with acetaminophen-induced hepatotoxicity (APAP) compared with silymarin alone. The solubility of silybin, the major and active component of silymarin, in the silymarin-SD group increased 23-fold compared with the silymarin group. The absorptive permeability of silybin increased by 4.6-fold and its efflux ratio decreased from 5.5 to 0.6 in the presence of TPGS. The results suggested that TPGS functioned as a solubilizing agent and permeation enhancer by inhibiting efflux pump. Thus, silybin concentrations in plasma and liver were increased in the silymarin-SD group and liver distribution increased 3.4-fold after repeated oral administration of silymarin-SD (20 mg/kg as silybin) for five consecutive days compared with that of silymarin alone (20 mg/kg as silybin). Based on higher liver silybin concentrations in the silymarin-SD group, the therapeutic effects of silymarin-SD in hepatotoxic rats were evaluated and compared with silymarin administration only. Elevated alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase levels were significantly decreased by silymarin-SD, silymarin, and TPGS treatments, but these decreases were much higher in silymarin-SD animals than in those treated with silymarin or TPGS. In conclusion, silymarin-SD (20 mg/kg as silybin, three times per day for 5 days) exhibited hepatoprotective properties toward hepatotoxic rats and these properties were superior to silymarin alone, which may be attributed to increased solubility, enhanced intestinal permeability, and increased liver distribution of the silymarin-SD formulation.

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Solubility and Dissolution Enhancement of Atorvastatin Calcium using Solid Dispersion Adsorbate Technique

Iraqi Journal of Pharmaceutical Sciences ( P-ISSN 1683 - 3597 E-ISSN 2521 - 3512) ◽

10.31351/vol28iss2pp105-114 ◽

2019 ◽

Vol 28 (2) ◽

pp. 105-114

Author(s):

Samer K. Ali ◽

Eman B. H. Al-Khedairy

Keyword(s):

Polyethylene Glycol ◽

Solid Dispersion ◽

Water Solubility ◽

Drug Carrier ◽

Solid Dispersions ◽

Poloxamer 407 ◽

Dissolution Enhancement ◽

Drug Solubility ◽

Scanning Calorimetry ◽

Poorly Soluble

Atorvastatin (ATR) is poorly soluble anti-hyperlipidemic drug; it belongs to the class II group according to the biopharmaceutical classification system (BCS) with low bioavailability due to its low solubility. Solid dispersions adsorbate is an effective technique for enhancing the solubility and dissolution of poorly soluble drugs. The present study aims to enhance the solubility and dissolution rate of ATR using solid dispersion adsorption technique in comparison with ordinary solid dispersion. polyethylene glycol 4000 (PEG 4000), polyethylene glycol 6000 (PEG 6000), Poloxamer188 and Poloxamer 407were used as hydrophilic carriers and Aerosil 200, Aerosil 300 and magnesium aluminium silicate (MAS) as adsorbents. All solid dispersion adsorbate (SDA) formulas were prepared in ratios of 1:1:1 (drug: carrier: adsorbent) and evaluated for their water solubility, percentage yield, drug content, , dissolution, crystal structure using X-ray powder diffraction (XRD) and Differential Scanning Calorimetry (DSC) studies and Fourier Transform Infrared Spectroscopy (FTIR) for determination the drug-carrier- adsorbate interaction. The prepared (SDA) showed significant improvement of drug solubility in all prepared formula. Best result was obtained with formula SDA12(ATR :Poloxamer407 : MAS 1:1:1) that showed 8.07 and 5.38 fold increase in solubility compared to solubility of pure ATR and solid dispersion(SD4) (Atorvastatin: Poloxamer 407 1:1) respectively due to increased wettability and reduced crystallinity of the drug which leads to improve drug solubility and dissolution .

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