The Faculty of Pharmacy discussed the Master’s Degree thesis, Preparation and Evaluation of Phospholipid Solid Dispersion of Atorvastatin Calcium as an Oral Solid Dosage Form,” by Bashar Kareem Kadhim Ghyadh, and the supervisor, Assist. Prof. Eman B.H. Al-Khedairy. in the Pharmaceutics Department. Atorvastatin (ATR) is a poorly water-soluble anti-hyperlipidemic drug. The drug belongs to the class II group, according to the biopharmaceutical classification system (BCS), with low bioavailability due to presystemic clearance in the gastrointestinal mucosa, high hepatic first-pass metabolism, and low water solubility. The aim of this study was to enhance the solubility and dissolution of this drug by the solid dispersion technique using phosphatidylcholine (PC) as an unusual carrier for ATR due to its lipid-lowering effect. This solid dispersion was prepared with or without adsorbents (magnesium aluminum silicate (MAS), silicon dioxide 15nm, silicon dioxide 30 nm, and calcium silicate) by the solvent evaporation method. The resulted PSD was evaluated for its percentage yield, drug content, solubility, and dissolution rate in comparison with the pure drug. The selected PSD was characterized for its crystallinity by powder X-ray diffraction study and differential scanning calorimetry, while the compatibility between the drug and the excipients was investigated by Fourier transformation infrared spectroscopy. Also, this formula was characterized for its flow properties in comparison to pure drugs to be prepared as immediate-release tablets using the required additives. The results showed that the best PSD was obtained by using magnesium aluminum silicate as an adsorbent in a ratio of 1:3:4 (ATR: PC: MAS), with a percentage yield of 88.65%, a drug content of 98.55%, and enhanced solubility by 21 folds compared to the pure drug with enhanced dissolution and flow properties. Also, this formula showed decreased crystallinity of the drug with good compatibility between the drug and the excipient. The best immediate release tablets were obtained using Avicel®PH102 as a diluent and Croscarmellose sodium 5% w/w as a superdisintegrant with the shortest disintegration time (38 ±1 sec.) and best drug release (91% within 15 min) in 0.05M phosphate buffer (pH 6.8), which was similar to the marketed drug (Lipitor®) with a slight difference between them in 0.1N HCl. In addition, the prepared tablets showed good stability after being stored for two months at different temperatures with the preservation of the amorphous form of the drug. Therefore, it may be concluded that phospholipid solid dispersion is a promising technique for enhancing the solubility and dissolution of poorly soluble drugs.
