In vitro and in vivo evaluation of novel immediate release carbamazepine tablets: Complexation with hydroxypropyl-β-cyclodextrin in the presence of HPMC

Pharmacokinetics and pharmacodynamics of cyclodextrin-based oral drug delivery formulations for disease therapy

Oral drug administration has become the most common and preferred mode of disease treatment due to its good medication adherence and convenience. For orally administered drugs, the safety, efficacy, and targeting ability requirements have grown as disease treatment research advances. It is difficult to obtain prominent efficacy of traditional drugs simply via oral administration. Numerous studies have demonstrated that cyclodextrins (CDs) can improve the clinical applications of certain orally administered drugs by enhancing their water solubility and masking undesirable odors. Additionally, deeper studies have discovered that CDs can influence disease treatment by altering the drug pharmacokinetics (PK) or pharmacodynamics (PD). This review highlights recent research progress on the PK and PD effects of CD-based oral drug delivery in disease therapy. Firstly, the review describes the characteristics of current drug delivery modes in oral administration. Besides, we minutely summarized the different CD-containing drugs, focusing on the impact of CD-based alterations in PK or PD of orally administered drugs in treating diseases. Finally, we deeply discussed current challenges and future opportunities with regard to PK and PD of CD-based oral drug delivery formulations.

Evaluating physiochemical properties of FDA-approved orally administered drugs

INTRODUCTION

Analyses of orally administered FDA-approved drugs from 1990 to 1993 enabled the identification of a set of physiochemical properties known as Lipinski's Rule of Five (Ro5). The original Ro5 and extended versions still remain the reference criteria for drug development programs. Since many bioactive compounds do not conform to the Ro5, we validated the relevance of and adherence to these rulesets in a contemporary cohort of FDA-approved drugs.

AREAS COVERED

The authors noted that a significant proportion of FDA-approved orally administered parent compounds from 2011 to 2022 deviate from the original Ro5 criteria (~38%) or the Ro5 with extensions (~53%). They then evaluated if a contemporary Ro5 criteria (cRo5) could be devised to better predict oral bioavailability. Furthermore, they discuss many case studies showcasing the need for and benefit of increasing the size of certain compounds and cover several evolving strategies for improving oral bioavailability.

EXPERT OPINION

Despite many revisions to the Ro5, the authors find that no single proposed physiochemical rule has universal concordance with absolute oral bioavailability. Innovations in drug delivery and formulation have dramatically expanded the range of physicochemical properties and the chemical diversity for oral administration.

Updates on applications of low-viscosity grade Hydroxypropyl methylcellulose in coprocessing for improvement of physical properties of pharmaceutical powders

Hydroxypropyl methylcellulose (HPMC) is an important polymeric excipient. Its versatility in terms of molecular weights and viscosity grades is the basis for its wide and successful application in the pharmaceutical industry. Low viscosity grades of HPMC (like E3 and E5) have been used as physical modifiers for pharmaceutical powders in recent years due to their unique physicochemical and biological properties (e.g., low surface tension, high T_g, strong hydrogen bonding ability, etc.). Such modification is the co-processing of HPMC with a drug/excipient to create composite particles (CPs) for the purpose of providing synergistic effects of functional improvement as well as of masking undesirable properties of the powder (e.g., flowability, compressibility, compactibility, solubility, stability, etc.). Therefore, given its irreplaceability and tremendous opportunities for future developments, this review summarized and updated studies on improving the functional properties of drugs and/or excipients by forming CPs with low-viscosity HPMC, analyzed and exploited the improvement mechanisms (e.g., improved surface properties, increased polarity, hydrogen bonding, etc.) for the further development of novel co-processed pharmaceutical powders containing HPMC. It also provides an outlook on the future applications of HPMC, aiming to provide a reference on the crucial role of HPMC in various areas for interested readers.

Design and Optimization of Rivaroxaban-Cyclodextrin-Polymer Triple Complex Formulation with Improved Solubility

Purpose

This study aimed to ensure the convenience of administration and reproducibility of efficacy, regardless of the meal, by improving the solubility of rivaroxaban (RIV).

Methods

RIV is a non-vitamin K antagonist oral anticoagulants that exhibits a coagulation effect by directly inhibiting coagulation factor Xa. However, RIV has a very low solubility; therefore, it must be administered with a meal at high doses. We used a drug- hydroxypropyl-beta-cyclodextrin (CD)-water-soluble polymer triple complex (R-C-P complex) to solubilize RIV. Using Minitab, we evaluated the effect of each factor on RIV solubility and developed an optimal R-C-P complex formulation. The amount of CD, amount of polymer, and polymer type were set as the independent variables X₁, X₂, and X₃, respectively. RIV solubility (Y₁) and dissolution rate for 45 min in pH 4.5 medium (Y₂) and pH 1.2 medium (Y₃) were set as response variables.

Results

The most efficient RIV solubilization effect was obtained from the composition using CD and HPMC 2208, and physicochemical properties and dissolution parameters were analyzed. RIV in the R-C-P complex was present in an amorphous form and showed high solubility. Unlike commercial products, it showed a 100% dissolution rate. The R-C-P complex formulation secured high RIV solubility and 100% release regardless of pH.

Conclusion

The results imply that high-dose RIV can be administered regardless of the meal, reducing the risk of changing the drug effect due to the patient's administration mistake.

3D printing of bioactive materials for drug delivery applications

INTRODUCTION

Three-dimensional (3D) printing, also known as additive manufacturing (AM), is a modern technique/technology, which makes it possible to construct 3D objects from computer-aided design (CAD) digital models. This technology can be used in the progress of drug delivery systems, where porosity has played important role in attaining an acceptable level of biocompatibility and biodegradability with improved therapeutic effects. 3D printing may also provide the user possibility to control the dosage of each ingredient in order to a specific purpose, and makes it probable to improve the formulation of drug delivery systems.

AREAS COVERED

This article covers the 3D printing technologies, bioactive materials including natural and synthetic polymers as well as some ceramics and minerals and their roles in drug delivery systems.

EXPERT OPINION

This technology is feasible to fabricate drug products by incorporating multiple drugs in different parts in such a mode that these drugs can release from the section at a predetermined rate. Furthermore, this 3D printing technology has the possible to transform personalized therapy to various age-groups by design flexibility and precise dosing. In recent years, the potential use of this technology can be realized in a clinical situation where patients will acquire individualized medicine as per their require.

A review of emerging technologies enabling improved solid oral dosage form manufacturing and processing

Tablets are the most widely utilized solid oral dosage forms because of the advantages of self-administration, stability, ease of handling, transportation, and good patient compliance. Over time, extensive advances have been made in tableting technology. This review aims to provide an insight about the advances in tablet excipients, manufacturing, analytical techniques and deployment of Quality by Design (QbD). Various excipients offering novel functionalities such as solubility enhancement, super-disintegration, taste masking and drug release modifications have been developed. Furthermore, co-processed multifunctional ready-to-use excipients, particularly for tablet dosage forms, have benefitted manufacturing with shorter processing times. Advances in granulation methods, including moist, thermal adhesion, steam, melt, freeze, foam, reverse wet and pneumatic dry granulation, have been proposed to improve product and process performance. Furthermore, methods for particle engineering including hot melt extrusion, extrusion-spheronization, injection molding, spray drying / congealing, co-precipitation and nanotechnology-based approaches have been employed to produce robust tablet formulations. A wide range of tableting technologies including rapidly disintegrating, matrix, tablet-in-tablet, tablet-in-capsule, multilayer tablets and multiparticulate systems have been developed to achieve customized formulation performance. In addition to conventional invasive characterization methods, novel techniques based on laser, tomography, fluorescence, spectroscopy and acoustic approaches have been developed to assess the physical-mechanical attributes of tablet formulations in a non- or minimally invasive manner. Conventional UV-Visible spectroscopy method has been improved (e.g. fiber-optic probes and UV imaging-based approaches) to efficiently record the dissolution profile of tablet formulations. Numerous modifications in tableting presses have also been made to aid machine product changeover, cleaning, and enhance efficiency and productivity. Various process analytical technologies have been employed to track the formulation properties and critical process parameters. These advances will contribute to a strategy for robust tablet dosage forms with excellent performance attributes.

Effect of chemical structure on complexation efficiency of aromatic drugs with cyclodextrins: The example of dibenzazepine derivatives

It is widely believed that the hydrophobic effect governs the binding of guest molecules to cyclodextrins (CDs). However, it is also known that high hydrophobicity of guest molecules does not always translate to the formation of stable inclusion complexes with CDs. Indeed, a plethora of other factors can play a role in the efficiency of guest-CD interactions, rendering structure-based prediction of the complexation efficiency with CDs a non trivial task. In this combined experimental and computational study, we examine the major structural factors governing complexation efficiency of polycyclic aromatic drug-like compounds with natural CDs, using as an example iminostilbene and its N-substituted derivatives. We find that purely hydrophobic IS derivatives show negligible complexation efficiency with CDs and only IS with hydrophilic substituents form stable inclusion complexes in water. We show that the balance between the guest solubility and its affinity to CDs is critical for the effective formation of inclusion complexes. Finally, our results demonstrate that guest-host hydrogen bonds facilitate the formation of crystalline inclusion complexes with CDs.

Hot liquid extrusion assisted drug-cyclodextrin complexation: a novel continuous manufacturing method for solubility and bioavailability enhancement of drugs

In this study, drug-cyclodextrin (CD) complexes were prepared using hot liquid extrusion (HLE) process with an aim to improve solubility and bioavailability of carbamazepine. Saturation solubility studies of CBZ in water and different pH media showed a pH-independent solubility. Phase solubility studies of CBZ at different molar concentrations of beta-cyclodextrin (β-CD) and hydroxypropyl beta-cyclodextrin (HP-β-CD) indicated A_L-type solubility profile with stability constants of 574 M⁻¹ and 899 M⁻¹ for β-CD and HP-β-CD. Drug-β-CD and drug-HP-β-CD complexes were prepared using HLE process and conventional methods (such as physical mixture, kneading method, and solvent evaporation) as well. Optimized complexes prepared using HLE viz. CBP-4 and CHP-2 showed a solubility of 4.27 ± 0.09 mg/mL and 6.39 ± 0.09 mg/mL as compared to plain CBZ (0.140 ± 0.007 mg/mL). Formation of drug-CD inclusion complexes was confirmed using DSC, FTIR, and XRD studies. Drug release studies indicated highest release of CBZ from CHP-2 (98.69 ± 2.96%) compared to CBP-4 (82.64 ± 2.45%) and plain drug (13.47 ± 0.54%). Complexes prepared using kneading showed significantly lesser drug release (KMB 75.52 ± 2.68% and KMH 85.59 ± 2.80%) as that of CHP-2 and CBP-4. Pre-clinical pharmacokinetic studies in Wistar rats indicated a significant increase in C_max, T_max, AUC, and mean residence time for CHP-2 compared to KMH and plain CBZ. All these results suggest that HLE is an effective method to increase the solubility of poorly water-soluble drugs.

Development of Pediatric Orodispersible Tablets Based on Efavirenz as a New Therapeutic Alternative

BACKGROUND

Efavirenz is the most used medication in the treatment of Acquired Immunodeficiency Syndrome (AIDS). The limited number of pediatric antiretroviral formulations approved by regulatory agencies is the most significant obstacle to adequate and efficient pharmacotherapy for this group of patients. The efavirenz has excellent therapeutic potential, but has low aqueous solubility/bioavailability.

METHODS

To minimize these limitations, multicomponent systems with β-cyclodextrin and polyvinylpyrrolidone K-30 were obtained. Due to the limited number of pediatric antiretroviral formulations, the development of a pediatric orodispersible tablet is an alternative that is thought easy to administer, since it disintegrates rapidly in the oral cavity. The multicomponent systems were obtained by the method of kneading and characterized by solubility test, X-ray diffraction, differential scanning calorimetry and infrared absorption spectroscopy by Fourier transform. The orodispersible tablets were prepared by direct compression. The quality control of hardness, friability, disintegration, and dissolution was performed. The influence of the components of the formulation on the characteristics of the tablets was evaluated through a 22 factorial design added with three central points, to compare the effect of the dependent variables on the responses.

RESULTS

An increase in drug solubility was observed, with a decrease in crystallinity. Besides that, an excellent dissolution profile presented with more than 83% of the drug's content dissolved in less than 15 minutes. Satisfactory disintegration time and friability were observed.

CONCLUSION

It was observed that reduced concentrations of mannitol decreased the hardness and disintegration time of the formulations. The orodispersible tablet composed of efavirenz: β- cyclodextrin: polyvinylpyrrolidone, favors greater absorption and bioavailability. It has several advantages for pediatric patients, as the dosage form disintegrates quickly in the mouth and does not require water for administration, thereby improving patient compliance with the treatment.

The Role of Functional Excipients in Solid Oral Dosage Forms to Overcome Poor Drug Dissolution and Bioavailability

Many active pharmaceutical ingredients (APIs) exhibit poor solubility and low dissolution rates in aqueous environments such as the luminal fluids of the gastrointestinal tract. The oral bioavailability of these compounds is usually very low as a result of their poor solubility properties. In order to improve the bioavailability of these poorly soluble drugs, formulation strategies have been applied as a means to improve their aqueous solubility and dissolution rates. With respect to formulation approaches, excipients can be incorporated in the formulation to assist in the dissolution process of the drug, or specialized dosage forms can be formulated that improve dissolution rate through various mechanisms. This paper provides an overview of selected excipients (e.g., alkalinizing agents, surfactants and sugars) that can be used in formulations to increase the dissolution rate as well as specialized dosage forms such as self-emulsifying delivery systems and formulation techniques such as inclusion complexes and solid dispersions. These formulation approaches are discussed with available examples with specific reference to positive outcomes in terms of drug solubility and bioavailability enhancement.

Use of Aloe Vera Gel-Based Edible Coating with Natural Anti-Browning and Anti-Oxidant Additives to Improve Post-Harvest Quality of Fresh-Cut ‘Fuji’ Apple

Recently, there is increasing use of edible and biodegradable films and packaging that are both environmentally friendly and functional for storage and market distribution. Fresh-cut ‘Fuji’ apples, harvested in an organic farm, were treated, using a spraying technique, with three new edible coatings based on Aloe vera gel (AVG—40% v/w) and in combination with natural additives: lemon essential oil (LEO—1% v/w) and hydroxypropyl methylcellulose (HPMC—0.1% v/w) and compared with untreated sample (CTR), the physicochemical and sensory characteristics and the proximate compounds were evaluated. During cold storage, weight loss, soluble solids content, and color of uncoated slices were reduced, while softening, ripening, browning, and acidity were accelerated. In contrast, the AVG/HPMC treatment significantly delayed the above parameters related to post-harvest quality loss, while the AVG/LEO treatment delayed the browning processes, maintaining an excellent color during cold storage. Concerning proximate compounds, the treatments did not alter their concentration in the fruit tissues. Sensory analyses revealed no detrimental effect on taste, aroma, or flavor. Our data evidenced the positive effect of Aloe vera gel in combination with LEO and HPMC on fresh-cut apple quality as an innovative and sustainable technique to maintain fresh-cut apple quality.

Simultaneous taste-masking and oral bioavailability enhancement of Ligustrazine by forming sweet salts

Ligustrazine (or Tetramethylpyrazine, TMP) is an active pharmaceutical ingredient that faces the challenges of bitter taste and low oral bioavailability by the commercial phosphate salt (TMP-Pho). We tackled these challenges by forming salts with two sweeteners, acesulfame (Acs) and saccharine (Sac). Both salts effectively masked the bitter taste of TMP. Compared to TMP-Pho, TMP-Sac shows 43% lower solubility and 11% lower permeability while TMP-Acs shows higher (two-fold) solubility but 24% lower permeability. Both TMP-Acs and TMP-Sac exhibited approximately 40% higher bioavailability through reducing the rate of TMP absorption. Thus, salt formation with both sweeteners simultaneously addressed the challenges brought about by the bitter taste and lower bioavailability of TMP.

Orodispersible Carbamazepine/Hydroxypropyl-β-Cyclodextrin Tablets Obtained by Direct Compression with Five-in-One Co-processed Excipients

The development of orodispersible tablets (ODTs) for poorly soluble and poorly flowable drugs via direct compression is still a challenge. This work aimed to develop ODTs of poorly soluble drugs by combining cyclodextrins that form inclusion complexes to improve wetting and release properties, and directly compressible co-processed excipients able to promote rapid disintegration and solve the poor flowability typical of inclusion complexes. Carbamazepine (CBZ) and hydroxypropyl-β-cyclodextrin (HPβCD) were used, respectively, as a model of a poorly soluble drug with poor flowability and as a solubilizing agent. Specifically, CBZ-an antiepileptic and anticonvulsant drug-may benefit from the studied formulation approach, since some patients have swallowing difficulties or fear of choking and are non-cooperative. Prosolv® ODT G2 and F-Melt® type C were the studied five-in-one co-processed excipients. The complex was prepared by kneading. Flow properties of all materials and main properties of the tablets were characterized. The obtained results showed that ODTs containing CBZ/HPβCD complex can be prepared by direct compression through the addition of co-processed excipients. The simultaneous use of co-processing and cyclodextrin technologies rendered ODTs with an in vitro disintegration time in accordance with the European Pharmacopoeia requirement and with a fast and complete drug dissolution. In conclusion, the combination of five-in-one co-processed excipients and hydrophilic cyclodextrins may help addressing the ODT formulation of poorly soluble drugs with poor flowability, by direct compression and with desired release properties.

Interaction of Native Cyclodextrins and Their Hydroxypropylated Derivatives with Carbamazepine in Aqueous Solution. Evaluation of Inclusion Complexes and Aggregates Formation

A detailed comprehensive study on how the formation of soluble and insoluble carbamazepine/cyclodextrins (CBZ/CD) complexes (with consequent changes in the solid-phase composition) depends on the CD structure is not yet available. Moreover, the study of possible influence of this drug on the tendency of CDs and their complexes to self-aggregate is still lacking. Phase-solubility studies demonstrated that CDs and CBZ form a range of soluble (A_L-type: αCD, βCD, and hydroxypropylated CDs) and insoluble (B_S-type: γCD) complexes depending on CD used. HPβCD proved to be the best CD solubilizer for CBZ forming the most stable complex with highest apparent solubility, whereas γCD was shown to be the best native CD. For the native CDs, CBZ solubilization increases with increasing CD cavity diameter (αCD ≪ βCD < γCD). Solid phases collected from phase-solubility studies were characterized by Fourier-transformed infrared spectroscopy, differential scanning calorimetry, and X-ray powder diffraction to elucidate their composition and crystalline structure. They provided similar conclusions being overall supportive of phase-solubility, osmolality, and permeation studies results. Solid CBZ was the only detected component for A_L-type profiles over the CD concentration range studied, whereas precipitation of poorly soluble CBZ/γCD complexes (B_S-type) was observed (i.e., at and beyond plateau region). Osmometry and permeation studies were applied to evaluate the effect of CBZ on the aggregate formation and also to elucidate their influence on CD complex solubility and permeation profile. Permeation method was shown to be the most effective method to detect and evaluate aggregate formation in aqueous γCD and HPβCD solutions containing CBZ. CBZ did not affect the HPβCD tendency to self-aggregate but CBZ did modify the aggregation behavior of γCD decreasing the apparent critical aggregation concentration value from 4.2% (w/v) (in pure aqueous γCD solution) to 2.5% (w/v) (when CBZ was present).

Influence of hydrophilic polymers on the complexation of carbamazepine with hydroxypropyl-β-cyclodextrin

In this study binary carbamazepine-hydroxypropyl-β-cyclodextrin, as well as ternary carbamazepine-hydroxypropyl-β-cyclodextrin-hydrophilic polymer systems were used to improve dissolution rate of carbamazepine. It has been shown that addition of hydrophilic polymers (Soluplus® and two types of hydroxypropyl methylcellulose-Metolose® 90SH-100 and Metolose® 65SH-1500) significantly increased solubilization capacity of hydroxypropyl-β-cyclodextrin for carbamazepine. Evaluation of carbamazepine-hydroxypropyl-β-cyclodextrin-hydrophilic polymer interactions using molecular modeling techniques showed interactions between carbamazepine, which dissociates from inclusion complexes and hydroxypropyl methylcellulose that can prevent crystallization of dissolved carbamazepine. These results can contribute to better understanding of drug-cyclodextrin-hydrophilic polymer interactions which are still not well understood. After evaluation of carbamazepine solubilization with hydroxypropyl-β-cyclodextrin and hydrophilic polymers, both binary carbamazepine-hydroxypropyl-β-cyclodextrin and ternary carbamazepine-hydroxypropyl-β-cyclodextrin-hydrophilic polymer systems were prepared by spray drying. The results of solid state characterization methods showed amorphous nature of carbamazepine in all spray dried systems, which together with the results of molecular modeling techniques indicates inclusion complex formation. Carbamazepine dissolution rate was significantly improved from spray dried formulations compared to pure drug. Binary carbamazepine-hydroxypropyl-β-cyclodextrin and ternary carbamazepine-hydroxypropyl-β-cyclodextrin-Soluplus® systems exhibited the fastest carbamazepine release, wherein the entire amount of carbamazepine was released during first 5 min.

Distinct gene expression responses of two anticonvulsant drugs in a novel human embryonic stem cell based neural differentiation assay protocol

Hazard assessment of chemicals and pharmaceuticals is increasingly gaining from knowledge about molecular mechanisms of toxic action acquired in dedicated in vitro assays. We have developed an efficient human embryonic stem cell neural differentiation test (hESTn) that allows the study of the molecular interaction of compounds with the neural differentiation process. Within the 11-day differentiation protocol of the assay, embryonic stem cells lost their pluripotency, evidenced by the reduced expression of stem cell markers Pou5F1 and Nanog. Moreover, stem cells differentiated into neural cells, with morphologically visible neural structures together with increased expression of neural differentiation-related genes such as βIII-tubulin, Map2, Neurogin1, Mapt and Reelin. Valproic acid (VPA) and carbamazepine (CBZ) exposure during hESTn differentiation led to concentration-dependent reduced expression of βIII-tubulin, Neurogin1 and Reelin. In parallel VPA caused an increased gene expression of Map2 and Mapt which is possibly related to the neural protective effect of VPA. These findings illustrate the added value of gene expression analysis for detecting compound specific effects in hESTn. Our findings were in line with and could explain effects observed in animal studies. This study demonstrates the potential of this assay protocol for mechanistic analysis of specific compound-induced inhibition of human neural cell differentiation.

Experimental and computational studies of physicochemical properties influence NSAID-cyclodextrin complexation

The objective of this research was to investigate physicochemical properties of an active pharmaceutical ingredient (API) that influence cyclodextrin complexation through experimental and computational studies. Native β-cyclodextrin (B-CD) and two hydroxypropyl derivatives were first evaluated by conventional phase solubility experiments for their ability to complex four poorly water-soluble nonsteroidal anti-inflammatory drugs (NSAIDs). Differential scanning calorimetry was used to confirm complexation. Secondly, molecular modeling was used to estimate Log P and aqueous solubility (S o) of the NSAIDs. Molecular dynamics simulations (MDS) were used to investigate the thermodynamics and geometry of drug-CD cavity docking. NSAID solubility increased linearly with increasing CD concentration for the two CD derivatives (displaying an AL profile), whereas increases in drug solubility were low and plateaued in the B-CD solutions (type B profile). The calculated Log P and S o of the NSAIDs were in good concordance with experimental values reported in the literature. Side chain substitutions on the B-CD moiety did not significantly influence complexation. Explicitly, complexation and the associated solubility increase were mainly dependent on the chemical structure of the NSAID. MDS indicated that each NSAID-CD complex had a distinct geometry. Moreover, complexing energy had a large, stabilizing, and fairly constant hydrophobic component for a given CD across the NSAIDs, while electrostatic and solvation interaction complex energies were quite variable but smaller in magnitude.

Strategies to address low drug solubility in discovery and development

Drugs with low water solubility are predisposed to low and variable oral bioavailability and, therefore, to variability in clinical response. Despite significant efforts to "design in" acceptable developability properties (including aqueous solubility) during lead optimization, approximately 40% of currently marketed compounds and most current drug development candidates remain poorly water-soluble. The fact that so many drug candidates of this type are advanced into development and clinical assessment is testament to an increasingly sophisticated understanding of the approaches that can be taken to promote apparent solubility in the gastrointestinal tract and to support drug exposure after oral administration. Here we provide a detailed commentary on the major challenges to the progression of a poorly water-soluble lead or development candidate and review the approaches and strategies that can be taken to facilitate compound progression. In particular, we address the fundamental principles that underpin the use of strategies, including pH adjustment and salt-form selection, polymorphs, cocrystals, cosolvents, surfactants, cyclodextrins, particle size reduction, amorphous solid dispersions, and lipid-based formulations. In each case, the theoretical basis for utility is described along with a detailed review of recent advances in the field. The article provides an integrated and contemporary discussion of current approaches to solubility and dissolution enhancement but has been deliberately structured as a series of stand-alone sections to allow also directed access to a specific technology (e.g., solid dispersions, lipid-based formulations, or salt forms) where required.

Comparison of cefpodoxime proxetil release and antimicrobial activity from tablet formulations: complexation with hydroxypropyl-β-cyclodextrin in the presence of water soluble polymer

This study aims to prove the complexation of cefpodoxime proxetil (CP) by hydroxypropyl-β-cyclodextrin (HP-β-CD) in the presence of sodium carboxymethyl cellulose (Na CMC), and makes a comparison of commercial tablets by dissolution and antimicrobial activity studies. The CP--HP-β-CD complex was prepared by kneading method and characterized by SEM, FTIR and DSC. The solubility method was used to investigate the effect of HP-β-CD and Na CMC on the solubility of CP. The complex tablets were prepared using direct compression method. Dissolution studies were performed with complex tablets and commercial tablets in pH 1.2, 4.5, 6.8 and 7.4 buffer solutions. It was observed that complexation occurred in all formulations, and HP-β-CD is able to increase CP solubility and dissolution rate of CP was improved from complex tablets, when compared with commercial tablets. Furthermore, the antimicrobial activity studies revealed that the CP--HP-β-CD complex and complex tablets were shown to have more effective antimicrobial activity than commercial tablets. It is evident from the results that complexation with HP-β-CD in the presence of Na CMC is feasible way to prepare a more efficient tablet formulation with improved dissolution and antimicrobial activity.