Polymer blends used to develop felodipine-loaded hollow microspheres for improved oral bioavailability

Polymeric Excipients in the Technology of Floating Drug Delivery Systems

The combination of targeted transport and improvement of the release profile of the active pharmaceutical ingredient (API) is a current trend in the development of oral medicinal products (MP). A well-known way to implement this concept is to obtain floating gastroretentive delivery systems that provide a long stay of the dosage form (DF) on the surface of the stomach contents. The nomenclature of excipients (Es) of a polymeric nature used in the technology of obtaining floating drug delivery systems (FDDS) is discussed. Based on the data presented in research papers, the most widely used groups of polymers, their properties, and their purpose in various technological approaches to achieving buoyancy have been determined. In addition, ways to modify the release of APIs in these systems and the Es used for this are described. The current trends in the use of polymers in the technology of floating dosage forms (FDF) and generalized conclusions about the prospects of this direction are outlined.

A Revolutionary Blueprint for Mitigation of Hypertension via Nanoemulsion

Hypertension is one of the most important causes of mortality, affecting the health status of the patient. At the same time, hypertension causes a huge health and economic burden on the whole world. The incidence and prevalence of hypertension are rising even among young people in both urban as well as rural communities. Although various conventional therapeutic moieties are available for the management of hypertension, they have serious flaws such as hepatic metabolism, reduced dose frequency, poor aqueous solubility, reduced bioavailability, and increased adverse effects, making the drug therapy ineffective. Therefore, it is required to design a novel drug delivery system having the capability to solve the constraints associated with conventional treatment of hypertension. Nanotechnology is a new way of using and manipulating the matter at the molecular level, whose functional organization is measured in nanometers. The applications of nanotechnology in the field of medicine provide an alternative and novel direction for the treatment of cardiovascular diseases and show excellent performance in the field of targeted drug therapy. Various nanotechnologies based drug delivery systems, such as solid lipid nanoparticles, nanosuspension, nanoemulsion, liposome, self-emulsifying systems, and polymeric nanoparticles, are available. Among them, nanoemulsion has provided a niche to supplement currently available therapeutic choices due to numerous benefits like stability, ease of preparation, enhanced drug absorption, reduced hepatic metabolism, increased dose frequency, enhanced bioavailability, and encapsulation of hydrophilic as well as hydrophobic drugs. This present review provides an in-depth idea about progression in treatment of hypertension, constraints for antihypertensive drug therapy, need of nanoemulsions to overcome these constraints, comparative analysis of nanoemulsions over other nanostructure drug delivery systems, pharmacodynamics studies of nanoemulsions for treatment of hypertension, recent patents for drug-loaded nanoemulsions meant for hypertension, and marketed formulations of nanoemulsions for hypertension.

Enhanced Oral Bioavailability of Felodipine from Solid Lipid Nanoparticles Prepared Through Effervescent Dispersion Technique

Felodipine (FLD), a dihydropyridine calcium channel blocker with excellent antihypertensive effect, is poorly soluble and undergoes extensive hepatic metabolism, which lead to poor oral bioavailability (about 15%) and limit its clinic application. The goal of this study was to develop solid lipid nanoparticles (SLNs) loading FLD to improve the oral bioavailability. The FLD loaded solid lipid nanoparticles (FLD-SLNs) were prepared by the effervescent dispersion technique developed by our laboratory, which might have some advantages over traditional methods. The FLD-SLNs showed desired particle characteristics with particle size (198.15 ± 1.82 nm), poly dispersity index (0.26 ± 0.02), zeta-potential (- 25.53 ± 0.60 mV), entrapment efficiency (95.65 ± 0.70%), drug loading (2.33 ± 0.10%), and a spherical appearance. Pharmacokinetic results showed that the FLD-SLNs presented 3.17-fold increase in area under the curve (AUC_(0-t)) compared with free FLD after oral administration in beagle dogs, which indicated that SLNs prepared using the effervescent dispersion technique can improve the bioavailability of lipophilic drugs like felodipine by enhancement of absorption and reduction first-pass metabolism.

HEMA based pH-sensitive semi IPN microgels for oral delivery; a rationale approach for ketoprofen

Objectives: The study aimed to develop safe, effective, and targeted drug delivery system for administration of nonsteroidal anti-inflammatory drugs (NSAIDs) in the form of microgels. We developed pH responsive microgels to overcome the mucosal damage caused by traditional immediate release dosage forms. Colon targeting and controlled release formulations have the potential to improve efficacy and reduce undesirable effects associated with NSAIDs.Methods: The pH sensitive oral hydrogel demonstrates the potential to target the colon. Cellulose acetate phthalate (CAP) and hydroxyethyl methacrylate (HEMA) based microgel particles were produced using a free radical polymerization technique using ammonium persulfate (APS) initiator and methylenebisacrylamide (MBA) as the crosslinking agent. Swelling and in-vitro drug release studies were performed at a range of pH conditions. The produced formulations were characterized using Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, scanning electron microscopy (SEM), and X-ray diffraction. Biocompatibility of the microgels was analyzed in cytotoxicity studies.Key findings: The swelling and release rate were negligible at pH 1.2, which confirmed the pH-responsiveness of CAP-co-poly(HEMA). The co-polymeric system prevents the release of ketoprofen sodium in the stomach owing to limited swelling at gastric pH, whilst promoting release at the basic pH observed in the colon. SEM images confirmed porous nature of the microgels that facilitate effective drug diffusion through the polymeric matrix. Cytotoxicity studies revealed biocompatibility of hydrogels.Conclusion: These investigations showed that that the controlled drug release and gastro-protective drug delivery of NSAIDS was achieved using CAP-co-poly(HEMA) microgel particles.

Premium ethylcellulose polymer based architectures at work in drug delivery

Premium ethylcellulose polymers are hydrophobic cellulose ether based biomaterials widely employed as biocompatible templates for the design of novel drug delivery systems. They are classified as United States Food and Drug Administration Generally-Recognized-As-Safe chemical substances and have been extensively utilized within the biomedical and pharmaceutical industries for over half a century. They have so far demonstrated the potential to modulate and improve the physiological performance of bioactives leading to the desired enhanced prophylactic and therapeutic outcomes. This review therefore presents a scholarly survey of inter-disciplinary developments focused on the functionalities of ethylcellulose polymers as biomaterials useful for the design of smart delivery architectures for relevant pharmacotherapeutic biomedical applications. Emphasis was placed on evaluating scientific resources related to recent advancements and future directions associated with its applications as delivery systems for drugs and biologics within the past decade thus complementing other specialized reviews showcasing the theme.

A Novel Micron-Size Particulate Formulation of Felodipine with Improved Release and Enhanced Oral Bioavailability Fabricated by Coaxial Electrospray

The antihypertensive drug felodipine (FD) is a typical biopharmaceutics classification system (BCS) II drug; thus, improving the dissolution rate of FD is very important to enhance its bioavailability. Besides, according to the in situ "close loop" perfusion assay, we found that the jejunum is the main absorptive site, then the duodenum and ileum. Consequently, a novel micron-size particulate of FD in a core-shell structure was fabricated by a coaxial electrospray technique; within the drug delivery system, Hypromellose K4M (HPMC K4M) was selected as a sheath material to prolong the retention time in the upper GI tract, while povidone K30 (PVP K30) was mixed with FD in the inner layer. The dissolution study in three different media (0.02% Tween-80 solution; phosphate buffer containing 0.02% Tween-80, pH 6.8; and HCl solution containing 0.02% Tween-80, pH 1.2) demonstrated that FD-loaded coaxial electrospray particles (F-COES) could greatly improve the dissolution of FD. Furthermore, in vivo pharmacokinetics revealed that F-COES emerged no changes in the half-life but significantly prolonged the t_max and increased the oral bioavailability. Collectively, this work supplies a promising drug release system that will improve the dissolution and enhance the bioavailability simultaneously for those poorly water-soluble drugs mainly absorbed in the upper GI tract.