Pharmacodynamic testing and new validated HPLC method to assess the interchangeability between multi-source orlistat capsules

Abstract

BackgroundOrlistat is an irreversible inhibitor of the lipase enzyme that prevents trigylcerides from being digested, thereby inhibiting triglyceride hydrolysis and absorption. The resultant reduced calorie uptake enables a positive effect on weight control. Systemic absorption of the drug is, therefore, not necessary for its mode of action. An alternative in vitro study (pharmacodynamic) has been introduced for this drug, as in vivo bioavailability studies are irrelevant with regard to the achievement of the product’s intended purposes.ObjectivesTo develop a new validated high-performance liquid chromatography (HPLC) method for the analysis of orlistat and to assess the potency and equivalence of three orlistat formulations using the pharmacodynamic method as a surrogate indicator of pharmaceutical interchangeability.MethodsA new HPLC method was developed for the analysis and for the dissolution studies of orlistat in capsules. Pancreatic lipase activity was measured for three different capsule products: Orlislim®, Slimcare®, and Xenical®, G1, G2, and the brand, respectively. Porcine pancreatic lipase and p-nitrophenyl butyrate (PNPB) were placed in a pH 7.4 reaction buffer at 37°C, and substrate hydrolysis was monitored by measuring absorbance changes at 410 nm; this was repeated on six capsules of each product. The inhibition was expressed by the concentration of product, which inhibited 50% of the activity of pancreatic lipase (IC50).ResultsThe new analytical method was suitable for orlistat analysis. Values of IC50 from regression lines and equations were 6.14, 8.43, and 7.80 μg/mL for Orlislim®, Xenical®, and Slimcare®, respectively.ConclusionPharmacodynamic studies of lipase inhibition could be used to support in vitro dissolution, which demonstrates interchangeability between generic and branded orlistat capsules. Moreover, it could be suggested as an alternative tool to bioequivalence studies for orlistat oral products.

Effect of in vitro simulated digestion on the physicochemical properties and pancreatic lipase inhibitory activity of fucoidan

“…To explore the relationship between fucoidan and the substrates (4‐nitrophenyl laurate) and orlistat, molecular docking analyses of orlistat and 4‐nitrophenyl laurate with pancreatic lipase were performed. Previous studies have shown that orlistat is an irreversible active site inhibitor of lipase 38 . Docking results showed that orlistat binds directly to the active center of pancreatic lipase with a binding free energy of −7.3 kcal mol −1 , binds with van der Waals forces to HIS264 in the active site, and forms hydrogen bonds with residues PHE78, HIS152, GLY77, and SER153, of which SER153 is also a critical amino acid in the active site.…”

“…Previous studies have shown that orlistat is an irreversible active site inhibitor of lipase. 38 Docking results showed that orlistat binds directly to the active center of pancreatic lipase with a binding free energy of −7.3 kcal mol −1 , binds with van der Waals forces to HIS264 in the active site, and forms hydrogen bonds with residues PHE78, HIS152, GLY77, and SER153, of which SER153 is also a critical amino acid in the active www.soci.org C Lu, Q Gu, X Yu wileyonlinelibrary.com/jsfa site. The free energy of binding of 4-nitrophenyl laurate to pancreatic lipase is −6.1 kcal mol −1 , forming a hydrogen bond with amino acid residue SER153 in the active site.…”

RP HPLC Method Development and Validation for Estimation of Orlistat in Pharmaceutical Dosage Forms

“…Orlistat is a carboxylic ester resulting from the formal condensation of the carboxy group of N-formyl-leucine, which is practically insoluble in water and slightly soluble in methanol. 3 It also improves insulin sensitivity and reduces body fat and serum leptin levels. Orlistat is a semisynthetic derivative of lipstatin; it is a potent and selective natural inhibitor of gastric and pancreatic lipases, which play an essential role in the digestion of dietary fat.…”

“…Despite numerous advantages of this drug, researchers are facing problems for estimation by HPLC because limited methods are available; only United State Pharmacopoeia (USP) method is the most reliable and effective. In the literature, there is an HPLC method for the determination of Orlistat in human plasma for pharmacokinetics studies 3 . However, there is no method for quantifying Orlistat in pharmaceutical dosage forms, especially in the floating drug delivery system.…”

Perfil metabolômico e avaliação biológica de espécies de Senna e Cassia

“…O método utilizado consiste em hidrolisar o substrato p-NPP na presença da lipase, formando o p-nitrofenol (p-NP) e o ácido palmítico (Figura 19). A extensão da inibição da lipase tem um impacto negativo na quantidade de p-NP liberado, sendo esta, medida espectrofotometricamente (ZAID et al, 2017).…”