Study on the impact of SNAC (sodium N-[8-(2-hydroxybenzoyl) amino] caprylate) on the bioavailability of ibandronate (IBN) in postmenopausal women

SNAC for Enhanced Oral Bioavailability: An Updated Review

The delivery of proteins and peptides via an oral route poses numerous challenges to improve the oral bioavailability and patient compliance. To overcome these challenges, as well as to improve the permeation of proteins and peptides via intestinal mucosa, several chemicals have been studied such as surfactants, fatty acids, bile salts, pH modifiers, and chelating agents, amongst these medium chain fatty acid like C10 (sodium caprate) and Sodium N-[8-(2-hydroxybenzoyl) amino] caprylate (SNAC) and its derivatives that have been well studied from a clinical perspective. This current review enumerates the challenges involved in protein and peptide delivery via the oral route, i.e., non-invasive routes of protein and peptide administration. This review also covers the chemistry behind SNAC and toxicity as well as mechanisms to enhance the oral delivery of clinically proven molecules like simaglutide and other small molecules under clinical development, as well as other permeation enhancers for efficient delivery of proteins and peptides.

Elucidating a Potential Mechanism of Permeability Enhancer Sodium N-[8-(2-hydroxybenzoyl) amino] Caprylate in Rats: Evidence of Lymphatic Absorption of Cyanocobalamin using the Mesenteric Lymph Duct Cannulated Rat

Oral administration is the most popular and convenient route for drug delivery, yet the success of oral drug delivery is dependent on the ADME properties of the drug. Among those ADME properties, permeability is considered one of the key attributes for successful oral drug absorption. Hence, the utilization of permeability enhancers to improve drug oral absorption is an important area of research in drug delivery. A multitude of data suggests that sodium N-[8-(2-hydroxybenzoyl) amino] caprylate (SNAC) is an effective permeability enhancer. Despite its success, the mechanism of how SNAC works to enhance the oral absorption of compounds is poorly understood. To better understand how SNAC worked, we investigated the hypothesis of SNAC promotes lymphatic absorption of target compounds. In this study, cyanocobalamin was used as the model compound and mesenteric lymph duct cannulated rats were used to investigate its absorption with or without SNAC. The present study demonstrated that SNAC enhanced the lymphatic absorption of cyanocobalamin when the two were co-dosed in rats. Furthermore, levels of SNAC in lymph fluid and the systemic circulation were higher when co-dosed with cyanocobalamin.

The combined effect of permeation enhancement and proteolysis inhibition on the systemic exposure of orally administrated peptides: Salcaprozate sodium, soybean trypsin inhibitor, and teriparatide study in pigs

Oral delivery of peptides and proteins is hindered by their rapid proteolysis in the gastrointestinal tract and their inability to permeate biological membranes. Various drug delivery approaches are being investigated and implemented to overcome these obstacles. In the discussed study conducted in pigs, an investigation was undertaken to assess the effect of combination of a permeation enhancer – salcaprozate sodium, and a proteolysis inhibitor – soybean trypsin inhibitor, on the systemic exposure of the peptide teriparatide, following intraduodenal administration. Results demonstrate that this combination achieves significantly higher Cmax and AUC (~10- and ~20-fold respectively) compared to each of these methodologies on their own. It was thus concluded that an appropriate combination of different technological approaches may considerably contribute to an efficient oral delivery of biological macromolecules.

•

Soybean trypsin inhibitor (SBTI) protects hPTH(1–34) from proteolysis in the intestine.

•

SNAC/SBTI combination significantly raises plasma exposure of oral hPTH(1–34).

•

Oral formulation hPTH(1–34)/SNAC/SBTI befits the PK profile for osteoporosis treatment.

•

Endoscopic intraduodenal delivery in pigs enables investigation of absorption mechanisms.

Evaluating the Pharmacokinetics and Systemic Effects of a Permeability Enhancer Sodium N-[8-(2-hydroxybenzoyl)amino] Caprylate in Rats

Oral administration is the preferred route for drug delivery and its success is highly dependent on a compound's ADME properties, of which, permeability plays a major role. Therefore, permeability enhancers are an attractive area of research in the pharmaceutical industry. Recent data suggest that sodium N-[8-(2-hydroxybenzoyl) amino] caprylate (SNAC) is an effective permeability enhancer, yet the pharmacokinetic (PK) and systemic effects of SNAC are poorly understood, specifically its oral bioavailability and systemic effects on distribution, which could influence the safety of certain drugs. To answer these questions, both in vitro and in vivo studies were conducted. Of 3 permeability enhancers (SNAC, 4-CNAB, and 5-CNAC), SNAC was found to have the greatest effect on the absorption of cyanocobalamin in rats. It was also found that SNAC is orally bioavailable (almost 40%) when dosed to rats. Based on these findings, tool compounds were co-dosed in rats to further evaluate the systemic effects of SNAC. Oral co-dosing of SNAC with an intravenous infusion of 2 poorly brain penetrant compounds, quinidine, and gabapentin, did not increase brain ISF: plasma ratio or total brain:plasma ratio for either of these compounds, implying that SNAC is effective only in the intestine at pharmacologically relevant concentrations.

Impact of Sodium N-[8-(2-Hydroxybenzoyl)amino]-caprylate on Intestinal Permeability for Notoginsenoside R1 and Salvianolic Acids in Caco-2 Cells Transport and Rat Pharmacokinetics

For drugs with high hydrophilicity and poor membrane permeability, absorption enhancers can promote membrane permeability and improve oral bioavailability. Sodium N-[8-(2-hydroxybenzoyl)amino]caprylate (SNAC) is a new kind of absorption enhancer that has good safety. To investigate the absorption enhancement effect of SNAC on non-polar charged and polar charged drugs and establish the absorption enhancement mechanism of SNAC, SNAC was synthesized and characterized. Two representative hydrophilic drugs—notoginsenoside R1 (R1) and salvianolic acids (SAs)—were selected as model drugs. In vitro Caco-2 cells transport and in vivo rat pharmacokinetics studies were conducted to examine the permeation effect of SNAC on R1 and SAs. R1, rosmarinic acid (RA), salvianolic acid B (SA-B) and salvianolic acid B (SA-A) were determined to compare the permeation enhancement of different drugs. The MTT assay results showed that SNAC had no toxicity to Caco-2 cells. The transepithelial electrical resistance (TEER) of Caco-2 cell monolayer displayed that SNAC facilitated passive transport of polar charged SAs through the membrane of epithelial enterocytes. The pharmacokinetics results demonstrated that area under the curve (AUC) of RA, SA-B and SA-A with administration of SAs containing SNAC was 35.27, 8.72 and 9.23 times than administration of SAs. T_max of RA, SA-B and SA-A were also prolonged. The AUC of R1 with administration of R1 containing SNAC was 2.24-times than administration of R1. SNAC is more effective in promoting absorption of SAs than R1. The study demonstrated that SNAC significantly improved bioavailability of R1 and SAs. What’s more, the effect of SNAC on absorption enhancement of charged drugs was larger than that of non-charged drugs. The current findings not only confirm the usefulness of SNAC for the improved delivery of R1 and SAs but also demonstrate the importance of biopharmaceutics characterization in the dosage form development of drugs.

Transcellular stomach absorption of a derivatized glucagon-like peptide-1 receptor agonist

Oral administration of therapeutic peptides is hindered by poor absorption across the gastrointestinal barrier and extensive degradation by proteolytic enzymes. Here, we investigated the absorption of orally delivered semaglutide, a glucagon-like peptide-1 analog, coformulated with the absorption enhancer sodiumN-[8-(2-hydroxybenzoyl) aminocaprylate] (SNAC) in a tablet. In contrast to intestinal absorption usually seen with small molecules, clinical and preclinical dog studies revealed that absorption of semaglutide takes place in the stomach, is confined to an area in close proximity to the tablet surface, and requires coformulation with SNAC. SNAC protects against enzymatic degradation via local buffering actions and only transiently enhances absorption. The mechanism of absorption is shown to be compound specific, transcellular, and without any evidence of effect on tight junctions. These data have implications for understanding how highly efficacious and specific therapeutic peptides could be transformed from injectable to tablet-based oral therapies.