Statistical optimisation of the mucoadhesivity and characterisation of multipolymeric propranolol matrices for buccal therapy

Bucco-Adhesive Film as a Pediatric Proper Dosage Form for Systemic Delivery of Propranolol Hydrochloride: In-vitro and in-vivo Evaluation

Objective

To formulate and assess bucco-adhesive films of propranolol hydrochloride for pediatric use.

Methods

Different films were formulated adopting mucin, polyvinyl alcohol, chitosan and carbopol. A drug/polymer compatibility study was conducted adopting differential scanning calorimetry and Fourier transform infrared spectroscopy. The prepared films were physically investigated for variation of weight, propranolol content, thickness, surface pH, proportion of moisture, folding endurance and mucoadhesion. In vitro drug release study and kinetic analysis of the corresponding data have been conducted. The optimized formulation was selected for a bioavailability study using albino rabbits and adopting a developed HPLC method. The pharmacokinetic parameters of the drug were calculated following administration of the optimized film and the corresponding marketed oral tablets to albino rabbits.

Key Finding

The compatibility study revealed the absence of drug/polymer interaction. The film formulations had suitable mucoadhesive and mechanical properties. The optimized formulation exhibited reasonable drug release that followed Higuchi diffusion pattern. The calculated AUC0-8h presented an enhancement in the bioavailability of propranolol hydrochloride from the selected film formulation by 1.9 times relative to the marketed propranolol oral tablets.

Conclusion

These findings support that propranolol hydrochloride bucco-adhesive film can be considered as a proper effective dosage form for pediatric delivery.

Improvement of bone microarchitecture in methylprednisolone induced rat model of osteoporosis by using thiolated chitosan-based risedronate mucoadhesive film

OBJECTIVE

In this study, we investigated the potential of thiolated chitosan-based mucoadhesive film, loaded with risedronate sodium in the treatment of osteoporosis.

SIGNIFICANCE

Risedronate sodium is a bisphosphonate derivative having very low bioavailability when administered through the oral route. Moreover, the adverse effects associated with the drug when administered through GIT necessitate an alternative and feasible route which can improve its bioavailability and therapeutic efficacy.

METHODS

Thiolation of chitosan was interpreted by different analytical techniques. The mucoadhesive films were prepared by the solvent evaporation method and evaluated for drug content analysis, swelling degree, mucoadhesive parameters, and permeation characterization. For the screening of preclinical efficacy and pharmacodynamic parameters, a methylprednisolone induced osteoporotic rat model was used. The trabecular microarchitecture and biochemical markers were evaluated for determination of bone resorption.

RESULTS

The different analytical characterization of synthesized thiolated chitosan revealed that chitosan was successfully incorporated with thiol groups. The formulation containing 2:1 ratio of thiolated chitosan and HPMC-4KM was found to have the maximum swelling degree, mucoadhesive strength with a good force of adhesion and better in vitro permeability compared to the marketed formulation. With respect to trabecular microarchitecture, the drug-loaded film formulation showed superior and promising results. Furthermore, the film formulation also improved the serum level of biomarkers better than the marketed formulation.

CONCLUSIONS

The results significantly suggest that risedronate loaded novel mucoadhesive film formulation could be a logical approach in the therapeutic intervention of osteoporosis.

Bilayered buccal films as child-appropriate dosage form for systemic administration of propranolol

Buccal mucosa has emerged as an attractive site for systemic administration of drug in paediatric patients. This route is simple and non-invasive, even if the saliva wash-out effect and the relative permeability of the mucosa can reduce drug absorption. Mucoadhesive polymers represent a common employed strategy to increase the contact time of the formulation at the application site and to improve drug absorption. Among the different mucoadhesive dosage forms, buccal films are particularly addressed for paediatric population since they are thin, adaptable to the mucosal surface and able to offer an exact and flexible dose. The objective of the present study was to develop bilayered buccal films for the release of propranolol hydrochloride. A primary polymeric layer was prepared by casting and drying of solutions of film-forming polymers, such as polyvinylpyrrolidone (PVP) or polyvinylalcohol (PVA), added with different weight ratios of gelatin (GEL) or chitosan (CH). In order to achieve unidirectional drug delivery towards buccal mucosa, a secondary ethylcellulose layer was applied onto the primary layer. Bilayered films were characterized for their physico-chemical (morphology, thickness, drug content and solid state) and functional (water uptake, mucoadhesion, drug release and permeation) properties. The inclusion of CH into PVP and PVA primary layer provided the best mucoadhesion ability. Films containing CH provided a lower drug release with respect to films containing GEL and increased the amount of permeated drug through buccal mucosa, thanks to its ability of interfering with the lipid organization. The secondary ethylcellulose layer did not interfere with drug permeation, but it could limit drug release in the buccal cavity.

Nanoliposomal artemisinin for the treatment of murine visceral leishmaniasis

Visceral leishmaniasis (VL) is a fatal, vector-borne disease caused by the intracellular protozoa of the genus Leishmania. Most of the therapeutics for VL are toxic, expensive, or ineffective. Sesquiterpenes are a new class of drugs with proven antimicrobial and antiviral activities. Artemisinin is a sesquiterpene lactone with potent antileishmanial activity, but with limited access to infected cells, being a highly lipophilic molecule. Association of artemisinin with liposome is a desirable strategy to circumvent the problem of poor accessibility, thereby improving its efficacy, as demonstrated in a murine model of experimental VL. Nanoliposomal artemisinin (NLA) was prepared by thin-film hydration method and optimized using Box–Behnken design with a mean particle diameter of 83±16 nm, polydispersity index of 0.2±0.03, zeta potential of −27.4±5.7 mV, and drug loading of 33.2%±2.1%. Morphological study of these nanoliposomes by microscopy showed a smooth and spherical surface. The mechanism of release of artemisinin from the liposomes followed the Higuchi model in vitro. NLA was free from concomitant signs of toxicity, both ex vivo in murine macrophages and in vivo in healthy BALB/c mice. NLA significantly denigrated the intracellular infection of Leishmania donovani amastigotes and the number of infected macrophages ex vivo with an IC₅₀ of 6.0±1.4 µg/mL and 5.1±0.9 µg/mL, respectively. Following treatment in a murine model of VL, NLA demonstrated superior efficacy compared to artemisinin with a percentage inhibition of 82.4%±3.8% in the liver and 77.6%±5.5% in spleen at the highest dose of 20 mg/kg body weight with modulation of cell-mediated immunity towards protective Th1 type. This study is the first report on the use of a liposomal drug delivery system for artemisinin as a promising alternative intervention against VL.

A new approach for the delivery of artemisinin: formulation, characterization, and ex-vivo antileishmanial studies

HYPOTHESIS

Artemisinin, a potential antileishmanial compound with poor bioavailability and stability has limited efficacy in visceral leishmaniasis. Encapsulating artemisinin into poly lactic-co glycolic nanoparticles may improve its effectiveness and reduce toxicity.

EXPERIMENTS

Artemisinin-loaded nanoparticles were prepared, optimized (using Box-Behnken design) and characterized by dynamic light scattering technique, Atomic force microscopy (AFM), Transmission electron microscopy (TEM) and Fourier Transform-Infra Red spectroscopy. Release kinetics of artemisinin from optimized nanoformulation was studied by dialysis method at pH 7.4 and 5.5. Cytotoxicity and antileishmanial activity of these nanoparticles was tested on murine macrophages by MTT assay and macrophage-infested Leishmania donovani amastigotes ex vivo, respectively.

FINDINGS

Artemisinin-loaded nanoparticles were 221±14nm in diameter, with polydispersity index, zeta potential, drug loading and entrapment efficiency of 0.1±0.015, -9.07±0.69mV, 28.03±1.14 and 68.48±1.97, respectively. AFM and TEM studies indicated that the particles were spherical in shape. These colloidal particles showed a sustained release pattern in vitro. Treatment with artemisinin-loaded nanoparticles significantly reduced the number of amastigotes per macrophage and percent infected macrophages ex vivo compared to free artemisinin. These nanoparticles were also non-toxic to macrophages compared to artemisinin alone.

Preparation, optimization and characteristic of huperzine a loaded nanostructured lipid carriers

The objective of the present work was to study the preparation, optimization and characteristics of Huperzine A (Hup A), an effective Traditional Chinese Medicine treatment of Alzheimer's disease (AD), loaded nanostructured lipid carriers (NLC). NLC were successfully prepared by a modified method of melt ultrasonication followed by high pressure homogenization using Cetyl Palmitate (CP) as the solid lipid, Miglyol((R))812 as the liquid lipid, Soybean phosphatidylcholine (Spc) and Solutol HS15 as the emulsifiers. The best formulation was optimized with a three-factor, three-level Box-Behnken design. Independent variables studied were the amount of the mixed lipid, the amount of the emulsifier mixture and lipid/drug ratio in the formulation. The dependent variables were the particle size, entrapment efficiency (EE) and drug loading (DL). Properties of NLC such as the morphology, particle size, zeta potential, EE, DL and drug release behavior were investigated, respectively. As a result, the designed nanoparticles showed nearly spherical particles with a mean particle size of 120 nm and -22.93 + or - 0.91 mV. The EE (%) and DL (%) could reach up to 89.18 + or - 0.28% and 1.46 + or - 0.05%, respectively. Differential scanning calorimetry (DSC) of Hup A loaded NLC indicated no tendency of recrystallisation. In vitro release studies showed a burst release at the initial stage and followed by a prolonged release of Hup A from NLC up to 96 h. The results suggest that the presented Hup A loaded NLC system is a potential delivery system for improving drug loading capacity and controlled drug release.

Buccal drug delivery of pravastatin sodium

The purpose of this study was to develop and optimize formulations of mucoadhesive bilayered buccal tablets of pravastatin sodium using carrageenan gum as the base matrix. The tablets were prepared by direct compression method. Polyvinyl pyrrolidone (PVP) K 30, Pluronic(R) F 127, and magnesium oxide were used to improve tablet properties. Magnesium stearate, talc, and lactose were used to aid the compression of tablets. The tablets were found to have good appearance, uniform thickness, diameter, weight, pH, and drug content. A 2(3) full factorial design was employed to study the effect of independent variables viz. levels of carrageenan gum, Pluronic F 127 and PVP K30, which significantly influenced characteristics like in vitro mucoadhesive strength, in vitro drug release, swelling index, and in vitro residence time. The tablet was coated with an impermeable backing layer of ethyl cellulose to ensure unidirectional drug release. Different penetration enhancers were tried to improve the permeation of pravastatin sodium through buccal mucosa. Formulation containing 1% sodium lauryl sulfate showed good permeation of pravastatin sodium through mucosa. Histopathological studies revealed no buccal mucosal damage. It can be concluded that buccal route can be one of the alternatives available for the administration of pravastatin sodium.

Controlled release from directly compressible theophylline buccal tablets

The aim of the current study was the development of theophylline buccal adhesive tablets using direct compression. Buccal adhesive formulations were developed using a water soluble resin with various combinations of mucoadhesive polymers. The prepared theophylline tablets were evaluated for tensile strength, swelling capacity and ex vivo mucoadhesion performance. Ex vivo mucoadhesion was assessed using porcine gingival tissue and the peak detachment forces were found to be suitable for a buccal adhesive tablet with a maximum of 1.5 N approximately. The effect of formulation composition on the release pattern was also investigated. Most formulations showed theophylline controlled release profiles depended on the grade and polymer ratio. The release mechanisms were found to fit Peppas' kinetic model over a period of 5h. In general the majority of the developed formulations presented suitable adhesion and controlled drug release.

Development and evaluation of buccal bioadhesive tablet of an anti-emetic agent ondansetron

The aim of the present study was to develop and evaluate a buccal adhesive tablet containing ondansetron hydrochloride (OH). Special punches and dies were fabricated and used while preparing buccal adhesive tablets. The tablets were prepared using carbopol (CP 934), sodium alginate, sodium carboxymethylcellulose low viscosity (SCMC LV), and hydroxypropylmethylcellulose (HPMC 15cps) as mucoadhsive polymers to impart mucoadhesion and ethyl cellulose to act as an impermeable backing layer. The formulations were prepared by direct compression and characterized by different parameters such as weight uniformity, content uniformity, thickness, hardness, swelling index, in vitro drug release studies, mucoadhesive strength, and ex vivo permeation study. As compared with the optimized formulation composed of OH--5 mg, CP 934--30 mg, SCMC LV--165 mg, PEG 6000--40 mg, lactose--5 mg, magnesium stearate--1.5 mg, and aspartame--2 mg, which gave the maximum release (88.15%), non-bitter (OH) that form namely ondansetron base and complexed ondansetron was used in order to make the selected formulation acceptable to human. The result of the in vitro release studies and permeation studies through bovine buccal mucosa revealed that complexed ondansetron gave the maximum release and permeation. The stability of drug in the optimized adhesive tablet was tested for 6 h in natural human saliva; both the drug and device were found to be stable in natural human saliva. Thus, buccal adhesive tablet of ondansetron could be an alternative route to bypass the hepatic first-pass metabolism and to improve the bioavailability of (OH).