Cubosomal functionalized block copolymer platform for dual delivery of linagliptin and empagliflozin: Recent advances in synergistic strategies for maximizing control of high-risk type II diabetes

A well-made chitosan-PVP block copolymer platform was equipped with highly ordered and uniform nano-channels. This highly adhesive block copolymer platform was designed to ensure the efficient co-delivery of two synergistic-acting hypoglycemic drugs. Linagliptin oral bioavailability is 30% due to poor permeability and intestinal degradation. Its pharmacokinetics shows a non-linear profile. Empagliflozin exhibited decreased permeability and decreased solubility in aqueous media between pH 1 and 7.5. Cubosomes were functionalized as a good microdomain to guest and improve the physicochemical characteristics of drug molecules with decreased permeability and solubility. Cubosomes loaded with linagliptin (linagliptin cubosomes (LCs)) and empagliflozin (empagliflozin cubosomes ECs) were separately prepared using the top-down method and optimized by applying 23 factorial design. Optimized cubosomal systems LCs (F3) and ECs (F4) were incorporated into a chitosan-PVP gel to obtain dual cubosome-loaded platforms (LECF) optimized through 22 factorial design. The permeation study from the optimized LECF (C1) ensured enhanced empagliflozin permeation alongside continued efflux for linagliptin, resolving potential risks due to its non-linear plasma profile. The in-vivo study revealed that AUC(0-∞) of linagliptin and empagliflozin was enhanced by 2- and threefold, respectively. Therefore, the chitosan-PVP block copolymer platform buccal application for the co-delivery of linagliptin and empagliflozin could contribute to enhanced clinical effectiveness in treating diabetes.

Preparation and Characterization of a Novel Mucoadhesive Carvedilol Nanosponge: A Promising Platform for Buccal Anti-Hypertensive Delivery

Carvedilol (CRV) is a non-selective third generation beta-blocker used to treat hypertension, congestive heart failure and angina pectoris. Oral administration of CRV showed poor bioavailability (25%), which might be ascribed to its extensive first-pass metabolism. Buccal delivery is known to boost drugs bioavailability. The aim of this study is to investigate the efficacy of bilosomes-based mucoadhesive carvedilol nanosponge for enhancing the oral bioavailability of CRV. The bilosomes were prepared, optimized and characterized for particle size, surface morphology, encapsulation efficiency and ex-vivo permeation studies. Then, the optimized formula was incorporated into a carboxymethyl cellulose/hydroxypropyl cellulose (CMC/HPC) composite mixture to obtain buccal nanosponge enriched with CRV bilosomes. The optimized bilosome formula (BLS9), showing minimum vesicle size, maximum entrapment, and highest cumulative in vitro release, exhibited a spherical shape with 217.2 nm in diameter, 87.13% entrapment efficiency, and sustained drug release for up to 24 h. In addition, ex-vivo drug permeation across sheep buccal mucosa revealed enhanced drug permeation with bilosomal formulations, compared to aqueous drug suspension. Consecutively, BLS9 was incorporated in a CMC/HPC gel and lyophilized for 24 h to obtain bilosomal nanosponge to enhance CRV buccal delivery. Morphological analysis of the prepared nanosponge revealed improved swelling with a porosity of 67.58%. The in vivo assessment of rats indicated that CRV-loaded nanosponge efficiently enhanced systolic/diastolic blood pressure, decreased elevated oxidative stress, improved lipid profile and exhibited a potent cardio-protective effect. Collectively, bilosomal nanosponge might represent a plausible nanovehicle for buccal delivery of CRV for effective management of hypertension.

Development of Salbutamol Sulphate Sublingual Films in Pullulan Matrix for Enhanced Bioavailability & Clinical Efficacy

BACKGROUND

Salbutamol sulphate (SS) is a model short-acting β2-adrenergic receptor agonist used for the relief of bronchospasm having poor bioavailability (50%) due to its extensive first-pass effect.

OBJECTIVE

Formulation of SS as fast dissolving sublingual films (FDSFs) using a biocompatible and biodegradable Pullulan polymer to bypass its metabolism in liver and offers a fast relieve of asthma.

METHOD

Films were prepared by solvent casting technique adopting 32 factorial design to study the effect of two independent variables namely; polymer type (HPMC E5, Pullulan, and L-HPC) and polymer to Maltodextrin ratio (3:0, 3:1 or 5:1). Films physicomechanical properties, disintegration time and in-vitro dissolution of the prepared formulations were evaluated.

RESULTS

Formula F3 containing Pullulan with Maltodextrin in a ratio 3:1 has the least disintegration time (26±2.6 seconds) and the highest dissolution rate (100%±0.5%) after four minutes. Pharmacokinetic study of the optimum formula F3 in healthy human volunteers revealed a shorter tmax (0.75±0.25 hour) compared to Ventolin® tablet 2 mg (2.1±0.37 hour). Clinical evaluation of F3 in 14 male asthmatic patients using ZAN Spirometry showed clinical improvement in lung function parameters when compared with Ventolin® tablets.

CONCLUSION

FDSFs significantly improved the bioavailability of SS and resulted in dramatic improvement in its clinical efficacy.