Sodium hydroxide pellets

Poly(lactic-co-glycolic acid) polymer (50:50) (PURASORB® PDLG 5002A, inherent viscosity of 0.2 dL/g) was generously donated from PURAC (Gorinchem, Netherlands). Bosentan was supplied by Parabolic (Chandigarh, India). Polyvinyl alcohol (PVA) (98–99% hydrolyzed with Low Mwt.) was purchased from Alfa Aesar (Karlsruhe, Germany). Sodium lauryl sulfate (SLS) was obtained from Oxford (Mumbai, India). Dichloromethane (DCM), sodium dihydrogen phosphate, sodium hydroxide pellets and methanol were obtained from Scharlau (Barcelona, Spain). Pure acetone was purchased from El Nasr pharmaceutical Chemicals Co. (Cairo, Egypt). All solvents used were HPLC grade.

CNB (99.79% purity) and CNB-H impurity were provided from Metrochem API Pvt Ltd, India. Xcopri® tablets were supplied from SK life science, Inc. Paramus, NJ07652. The tablets are labeled to contain 100.0 mg CNB. Both acetonitrile and methanol were HPLC grade and obtained from Scharlau, Spain. Diluent is prepared by mixing acetonitrile and purified water in the ratio of 40:60, % v/v. Excipients used in preparation of spiked placebo include microcrystalline cellulose (FMC, USA), colloidal silicon dioxide, (Evonik, Germany), lactose monohydrate (DFE Pharma, Germany), sodium starch glycolate (JRS Pharma, USA), magnesium stearate (Italmatch, Italy), and film coating agents: FD&C Blue# 2/indigo carmine aluminum lake, iron oxide red, iron oxide yellow (Karma, Egypt), polyethylene glycol 3350 (IMCD, Egypt), polyvinyl alcohol-part hydrolyzed (East Hony, China), Talc (Elgomohorya, Egypt), and titanium dioxide (Kronos, USA). Hydrogen peroxide (Merck, Germany, 30%), hydrochloric acid (Scharlau, Spain, 36.5–38%) and sodium hydroxide pellets (Scharlau, Spain, 98.5%) were utilized in the study of degradation conditions.

Monomers used were melamine (99%, Acros Organics, Geel (Belgium)) and formaldehyde (37%, ACS reagent, stab. 10–15% methanol, Acros Organics). n-eicosane (99%, Acros Organics) was used as the encapsulated material and sodium dodecylbenzenesulfonate (SDBS, technical grade, Sigma Aldrich, Darmstadt (Germany)) as surfactant in the emulsion process. To regulate the pH during the synthesis, sodium hydroxide (pellets, Scharlab, Barcelona (Spain)) and acetic acid (glacial, 99%, Alpha Aesar, Kandel (Germany)) were used.