Abstract
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 .
Highlights
The solubility of drug molecules is a significant determinant of the dissolution rate because of dissolution rate is closely tied to solubility [1]
Significant enhancement in solubility of Atorvastatin calcium (ATR) (p poloxamer188 > PEG6000>PEG4000
Further improvement in solubility was obtained when ATR prepared as solid dispersion adsorbate (SDA) in comparison to that obtained by Solid dispersion (SD). that can be explained to be due to adsorption of ATR on the hydrophilic adsorbent and increase the surface area of ATR that exposed to the solvent, whereby the drug is bound to the adsorbent and cannot agglomerate which results in enhanced wettability of the drug particles and its solubility [27,28]
Summary
The solubility of drug molecules is a significant determinant of the dissolution rate because of dissolution rate is closely tied to solubility [1]. Atorvastatin calcium (ATR) is an antihyperlipidemic agent able to lowering blood cholesterol levels by the reversible inhibition of HMG-CoA reductase, a rate-limiting step in the cholesterol biosynthesis. It represents one of the most widely administered oral statins used in case of elevated plasma levels of cholesterol, triglycerides, low-density lipoproteins in addition to its ability to elevate the high-density lipoproteins [4]. The drug is very slightly soluble in distilled water with the pKa value of 4.46 and Log p values of 6.36 in octanol/water It has an absolute oral bioavailability of 12 %. Many authors have worked to improve the solubility and dissolution rate of ATR by preparing microsphere, emulsion, nanosuspension, self- microemulsion, solid dispersion [7]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
