Polymer in Pharmaceutical Drug Delivery System

The current review article focuses on polymers in pharmaceutical drug delivery of therapeutic agents. These dosage forms include tablets, patches, tapes, films, semisolids and powders. Polymers are the backbone of a pharmaceutical drug delivery system as they control the release of the drug from the device. Biodegradable polymers attracts the attention of its use as they can be degraded to non‐toxic monomers and most important, a constant rate of drug release can be achieved from a biodegradable polymer based controlled release device. Natural polymers can be used as the means of achieving predetermined rates of drug delivery and their physico‐chemical characteristics with the ease of availability provide a platform to use it as a polymer for drug delivery systems. Biodegradable polymers have been widely used in biomedical applications because of their known biocompatibility and biodegradability. In the biomedical area, polymers are generally used as implants and are expected to perform long term service. These improvements contribute to make medical treatment more efficient and to minimize side effects and other types of inconveniences for patients. The main role of polymer is to protect drug from physiological environment and prolong release of drug to improve its stability. The drug is release from polymer by diffusion, degradation and swelling. In addition to this review presents characteristics and behaviours of plant derived and mucoadhesive polymers which are currently used in drug delivery.

EFFECTIVENESS OF THE NATURAL-BASED PRODUCTS AND MUCOADHESIVE FOR RECURRENT APHTHOUS STOMATITIS THERAPY: A SYSTEMATIC REVIEW

The objective was to describe and recommend the most effective combination of Natural-Based Product (NBP) and mucoadhesive for Recurrent Aphthous Stomatitis (RAS) treatment. This systematic review writing was based on PRISMA guidelines. The articles published in the last 10 y were selected using PubMed and Google Scholar database carried out during May 2021. The keywords were: natural-based product, mucoadhesive, and Recurrent Aphthous Stomatitis. The risk of bias was assessed using the Oxford Quality Scoring System. Six articles of Randomized Controlled Trial were selected. The NBP were: Aloe vera, Myrrh, Curcuma longa, propolis, ginger, Punica granatum flower, and sesame oil. The drug’s formulation was: gel, film, and spray. The mucoadhesive polymers as vehicles were Hydroxy Propyl Ethyl Cellulose (HPEC), Hydroxy Propyl Methylcellulose (HPMC), Benzocaine, Tragacanth Gum, Carbomer 934, Sodium CMC (carboxymethyl cellulose), and chitosan. Curcuma longa 10 mg/g with HPMC was the most effective to relieve pain, while Punica granatum flower extract with Carbomer 934 and Sodium CMC was the most effective to reduce the ulcer size in RAS. Both of the formulations were in gel form.

Vaginal delivery of clotrimazole by mucoadhesion for treatment of candidiasis

The aim of this study was to prepare mucoadhesive vaginal tablets of clotrimazole for treatment of vaginal candidiasis. A combination of mucoadhesive polymers like HPMC K100M, Sodium CMC, and Eudragit L100 were used in different ratios prepare solid dispersions to enhance its solubility. Tablets were prepared by the wet granulation method. Solid dispersions were evaluated for saturation solubility. All tablet batches were evaluated for weight variation, hardness, friability, drug content, swelling index, in vitro drug release study, ex vivo diffusion and mucoadhesive strength. FTIR spectra showed there was no interaction between the drug and the excipients. HPMC K100 M increased the solubility of clotrimazole in simulated vaginal fluid at pH 4.5. Eudragit L100 was shown to increase the swelling and mucoadhesive strength of the tablet, i.e., 3.03 and 3.29 g. The in vitro and ex vivo release of all 9 batches showed between 61 to 78% release in 8h. Ex vivo diffusion studies using sheep vaginal membrane showed 43 to 59% in 6h in simulated vaginal fluid. The release and flux were nearly comparable to marketed tablet i.e., Candid-V6. The drug release of all batches followed the Korsmeyer-Peppas kinetic model, and the mechanism was found to be non‐Fickian/anomalous. Keywords: Clotrimazole, solid dispersion, HPMC K100M, Eudragit L100, Sodium CMC.

AN ASSESSMENT ON BUCCAL MUCOADHESIVE DRUG DELIVERY SYSTEM

Buccal drug delivery system (BDDS) has won a variety of exposure and traction as it possesses plenty of advantages and benefits as evaluate to different mucosal drug delivery systems. Buccal path for systemic drug delivery, the use of mucoadhesive polymers twill significantly increase the efficacy of many tablets, has been of outstanding interest over the previous couple of decades. This article affords a precise of BDDS mechanisms, consisting of a composition of the oral mucosa, delivery mechanism, numerous forms of BDDS, formulation, assessment and application of BDDS. Additionally, this text affords a precis over the patents, advertised products and destiny factors of BDDS. In this evaluation article, we've got tried to assemble the maximum significant reports (1988 to 2021) of formulation, assessment, application, patents of BDDS. This review will help pharmaceutical researchers to clarify the potential of BDDS to overcome the various existing drug delivery dispute like the efficiency of absorption, permeability and bioavailability of drugs.

Posterior Segment Ophthalmic Drug Delivery: Role of Muco-Adhesion with a Special Focus on Chitosan

Posterior segment eye diseases (PSEDs) including age macular degeneration (AMD) and diabetic retinopathy (DR) are amongst the major causes of irreversible blindness worldwide. Due to the numerous barriers encountered, highly invasive intravitreal (IVT) injections represent the primary route to deliver drugs to the posterior eye tissues. Thus, the potential of a more patient friendly topical route has been widely investigated. Mucoadhesive formulations can decrease precorneal clearance while prolonging precorneal residence. Thus, they are expected to enhance the chances of adherence to corneal and conjunctival surfaces and as such, enable increased delivery to the posterior eye segment. Among the mucoadhesive polymers available, chitosan is the most widely explored due to its outstanding mucoadhesive characteristics. In this review, the major PSEDs, their treatments, barriers to topical delivery, and routes of topical drug absorption to the posterior eye are presented. To enable the successful design of mucoadhesive ophthalmic drug delivery systems (DDSs), an overview of mucoadhesion, its theory, characterization, and considerations for ocular mucoadhesion is given. Furthermore, chitosan-based DDs that have been explored to promote topical drug delivery to the posterior eye segment are reviewed. Finally, challenges of successful preclinical to clinical translation of these DDSs for posterior eye drug delivery are discussed.

Development of Mucoadhesive Film-Forming Systems Containing Black Ginger Extract for Aphthous Ulcers

Film-forming systems (FFSs) were developed by using Eudragit® E100 as a film former. Kaempferia parviflora (black ginger) extract was used as an anti-inflammatory agent for aphthous ulcers. The FFS could rapidly form a thin film in only 5 s when it was applied to a wet surface e.g. an aphthous ulcer. When the FFS was applied to a dry surface, the FFS without extract could form a film in 2-4 min. The incorporation of this extract contributed to delaying the film-formation time in the dry state; hence, the film-forming time increased to 6-8 min. The mucoadhesive property of FFSs was verified with the wash-off method. To simulate oromucosal conditions, the FFSs were applied on a cellophane membrane coated with mucin and washed by phosphate buffer of pH 6.8. The formulations without mucoadhesive polymers could not withstand flushing with a medium for more than 8 min without dislodging. Therefore, three different mucoadhesive agents were trialed: PVP K90, HPMC E15 LV, and HPC SL. The highest adhesion results were obtained when HPMC was added at 5%(w/w) as well as, the residence time was 22 min. In vitro release of black ginger extract from FFS showed a gradual release for 2 h. This study indicated that the FFS with HPMC E15 LV was an appropriate alternative formulation as a local delivery system for an aphthous ulcer.

EFFECT OF SELECTED MUCOADHESIVE POLYMERS ON PHARMACEUTICAL PROPERTIES OF CHITOSAN FORMULATIONS

The aim of this study was to develop a technical process and composition of mucoadhesive hydrogels containing benzocaine, based on different concentration ratios of the natural polymers chitosan and xanthan gum. For this purpose, lyophilisates of polymeric complexes with the quantitative ratios of 0.5:1, 1:1 and 1:0.5 chitosan to xanthan gum were prepared and subsequently used to prepare hydrogels of various concentrations. The physicochemical properties and pharmaceutical availability of benzocaine were evaluated and diffractograms and Fourier-transform infrared spectra of individual polymers and their polyelectrolyte complexes were compared. The 1:1 formulation exhibited the highest water absorption capacity and the gels showed the highest viscosity and the shortest blurring times. More chitosan increased carrier texture parameters, including hardness, cohesiveness and consistency, whereas more xanthan gum led to the longest gel blurring times and improved carrier stability. The concentration ratio of chitosan to xanthan gum in lyophilisates determined the viscosity, texture, spreadability and blurring time of the gels. Increases in lyophilisate percentage in the gels also affected the physicochemical properties of the carrier. In addition, the proportions of polymers in the mixture did not influence the availability of the drug from the prepared gel; this factor appears to depend more on the lyophilisate content in the carrier. Variations in the ratio of chitosan to xanthan gum in the polymer complex as well as lyophilisate percentage in the gel may impact the properties of the hydrogel and its efficacy as a carrier for therapeutic substances administered to the oral cavity mucosa.