Sublingual fast dissolving niosomal films for enhanced bioavailability and prolonged effect of metoprolol tartrate

Ayat Allam, Gihan Fetih Department of Pharmaceutics, Faculty of Pharmacy, Assiut University, Assiut, Egypt Abstract: The aim of the present work was to prepare and evaluate sublingual fast dissolving films containing metoprolol tartrate-loaded niosomes. Niosomes were utilized to allow for prolonged release of the drug, whereas the films were used to increase the drug’s bioavailability via the sublingual route. Niosomes were prepared using span 60 and cholesterol at different drug to surfactant ratios. The niosomes were characterized for size, zeta-potential, and entrapment efficiency. The selected niosomal formulation was incorporated into polymeric films using hydroxypropyl methyl cellulose E15 and methyl cellulose as film-forming polymers and Avicel as superdisintegrant. The physical characteristics (appearance, texture, pH, uniformity of weight and thickness, disintegration time, and palatability) of the prepared films were studied, in addition to evaluating the in vitro drug release, stability, and in vivo pharmacokinetics in rabbits. The release of the drug from the medicated film was fast (99.9% of the drug was released within 30 minutes), while the drug loaded into the niosomes, either incorporated into the film or not, showed only 22.85% drug release within the same time. The selected sublingual film showed significantly higher rate of drug absorption and higher drug plasma levels compared with that of commercial oral tablet. The plasma levels remained detectable for 24 hours following sublingual administration, compared with only 12 hours after administration of the oral tablet. In addition, the absolute bioavailability of the drug (ie, relative to intravenous administration) following sublingual administration was found to be significantly higher (91.06%±13.28%), as compared with that after oral tablet administration (39.37%±11.4%). These results indicate that the fast dissolving niosomal film could be a promising delivery system to enhance the bioavailability and prolong the therapeutic effect of metoprolol tartrate. Keywords: anti-hypertensive, β1- antagonist, pharmacokinetic

From the mine to cancer therapy: natural and biodegradable theranostic silicon nanocarriers from diatoms for sustained delivery of chemotherapeutics

Drug delivery using synthetic nanoparticles including porous silicon has been extensively used to overcome the limitations of chemotherapy. However, their synthesis has many challenges such as lack of scalability, high cost, and the use of toxic materials with concerning environmental impact. Nanoscale materials obtained from natural resources are an attractive option to address some of these disadvantages. In this paper, a new mesoporous biodegradable silicon nanoparticle (SiNP) drug carrier obtained from natural diatom silica mineral available from the mining industry is presented. Diatom silica structures are mechanically fragmented and converted into SiNPs by simple and scalable magnesiothermic reduction process. Results show that SiNPs have many desirable properties including high surface area, high drug loading capacity, strong luminescence, biodegradability, and no cytotoxicity. The in-vitro release results from SiNPs loaded with anticancer drugs (doxorubicin) demonstrate a pH-dependent and sustained drug release with enhanced cytotoxicity against cancer cells. The cells study using doxorubicin loaded SiNPs shows a significantly enhanced cytotoxicity against cancer cells compared with free drug, suggesting their considerable potential as theranostic nanocarriers for chemotherapy. Their low-cost manufacturing using abundant natural materials and outstanding chemotherapeutic performance has made them as a promising alternative to synthetic nanoparticles for drug delivery applications.Shaheer Maher, Tushar Kumeria, Ye Wang, Gagandeep Kaur, Dina Fathalla, Gihan Fetih, Abel Santos, Fawzia Habib, Andreas Evdokiou, Dusan Losi

Treatment of Irreducible Traumatic Anterior Shoulder Dislocation Caused by Subscapularis Tendon Interposition

Irreducible shoulder dislocation is an uncommon event. When it does occur, blocks to reduction can include bone, labrum, rotator cuff musculature, or tendon. Concomitant rotator cuff tear at the time of initial dislocation is not an exclusive complication of anterior shoulder dislocation in the older population. Indeed, rotator cuff tear should not be excluded based solely on the patient's age. Rotator cuff interposition is not an uncommon complication after anterior dislocation of the shoulder. It should be suspected when there is incongruency of the joint and persistent subluxation on postreduction radiographs. If such incongruence or subluxation is seen, a computed tomographic (CT) or magnetic resonance imaging (MRI) scan must then be obtained to determine the nature of the interposed soft tissues. The key to treatment is early diagnosis and adequate imaging. Open reduction and repair of the rotator cuff should be performed. We present a technique for treating irreducible anterior shoulder dislocation caused by interposition of the subscapularis tendon. Both CT and MRI observations, along with intraoperative findings and surgical technique, are discussed

Application of bile acids in drug formulation and delivery

Bile acids are naturally produced in humans and are known to provide human health benefits through their endocrinological, microfloral, metabolic and other åffects that are still to be elucidated. In recent years, there has been a growing interest in using bile acids as absorption enhancers for drug delivery. Bile acids are amphiphilic molecules with a unique ability to facilitate and promote drug permeation through biological membranes. The role of bile acids in promoting drug permeation has been experimentally illustrated in various pharmaceutical formulations including oral, nasal, ocular, buccal, pulmonary and rectal delivery as well as through the blood–brain barrier. Recently, bile acids have drawn attention in the field of drug delivery due to their ability to act as a drug carrier system in the form of mixed micelles, bilosomes and chemical conjugates with drug molecules. Bile acids have demonstrated a unique ability to enhance the epithelial transport of hydrophilic drugs through the paracellular route and that of hydrophobic compounds through both paracellular and transcellular routes. The aim of this review is to discuss various chemical and pharmaceutical aspects of BAs and their potential applications in drug formulation and delivery