Development, evaluation and pharmacokinetics of time-dependent ketorolac tromethamine tablets

3D printed pH-responsive tablets containing N-acetylglucosamine-loaded methylcellulose hydrogel for colon drug delivery applications

The pH-responsive drug release approach in combination with three-dimensional (3D) printing for colon-specific oral drug administration can address the limitations of current treatments such as orally administered solid tablets. Such existing treatments fail to effectively deliver the right drug dosage to the colon. In order to achieve targeted drug release profiles, this work aimed at designing and producing 3D printed tablet shells using Eudragit® FS100 and polylactic acid (PLA) where the core was filled with 100 µl of N-acetylglucosamine (GlcNAc)-loaded methyl cellulose (MC) hydrogel. To meet the requirements of such tablets, the effects of polymer blending ratios and MC concentrations on physical, thermal, and material properties of various components of the tablets and most importantly in vitro drug release kinetics were investigated. The tablets with 80/20 wt% of Eudragit® FS100/PLA and the drug-loaded hydrogel with 30 mg/ml GlcNAc and 3% w/v MC showed the most promising results having the best printability, processability, and drug release kinetics besides being non-cytotoxic. Manufacturing of these tablets will be the first milestone in shifting from the conventional "one size fits all" approach to personalized medicine where different dosages and various combinations of drugs can be effectively delivered to the inflammation site.

Formulation and Development of Flurbiprofen Colon-Specific Eudragit Coated Matrix Tablets: Use of a Novel Crude Banana Peel Powder as a Time-Dependent Polymer

The rationale for the current investigation is to study the crude banana peel (CBP) powder efficiency as a novel natural time-dependent polymer along with a pH-sensitive polymer to develop flurbiprofen colon-specific tablets. The direct compression method is utilized to prepare the flurbiprofen-CBP matrix tablets using 9 mm punches on the rotary tableting machine and subsequently coated with Eudragit® S 100 by a dip coating method. The tablets were evaluated for various tableting properties and in vitro drug release studies. From the results of dissolution studies, the F6 formulation showed negligible drug release (5.76% in 5 h) in the upper gastrointestinal tract and progressive release in the colon (99.08% in 24 h). Mean dissolution time, T10%, and T80% were found to be 13.33 h, 5.8 h, and 20.7 h, respectively, which explains the efficiency of the present combination of polymers for colon-specific drug release. From the dissolution studies results of stability studies, the similarity index was calculated and found to be 74.75. In conclusion, utilizing CBP as a natural, time-dependent polymer in conjunction with Eudragit® S 100 to develop the flurbiprofen tablets seems like a promising approach for delivering drugs specifically to the colon.

Multiparticulate Systems of Meloxicam for Colonic Administration in Cancer or Autoimmune Diseases

The aim of this research is the development of new colonic release systems of meloxicam (MLX) a non-steroidal anti-inflammatory drug (NSAIDs) with pH and time-dependent vehicles for cancer or autoimmune diseases. The colon has a higher pH than the rest of the gastrointestinal tract (GIT) and this can be used as a modified release strategy. Eudragit^® polymers are the most widely used synthetic products in the design of colonic release formulations because they might offer mucoadhesiveness and pH-dependent release. Colonic delivery systems produced with pH-dependent and permeable polymers (FS-30D) or with pH-independent and low permeability polymers (NM-30D), must dissolve at a pH range of 6.0–7.0 to delay the release of the drug and prevent degradation in the GIT, before reaching the colon. The conditions prepared to simulate a gastrointestinal transit showed the CNM multiparticulate system, composed of Eudragit^® NM and cellulose, as the best release option for MLX with a more sustained release with respect to the other formulations. CNM formulation followed Higuchi and First-order release kinetics, thus MLX release was controlled by a combination of diffusion and polymers swelling/eroding processes.

Preparation and in vitro/in vivo evaluation of a clonidine hydrochloride drug-resin suspension as a sustained-release formulation

OBJECTIVE

The purpose of the present study was to prepare a clonidine hydrochloride (CH) sustained-release suspension.

METHODS

The processes involved in the drug formulation included drug loading, impregnating, and suspension preparation. Clonidine hydrochloride drug-resin complexes (CH-DRC) were prepared using the bath method and the CH-DRC impregnated before the microencapsulation process. Based on the bottom spray fluidized bed coating method, the CH microencapsulated drug-resin complexes (CH-MC) were also prepared using Surelease^® (the suspension of ethyl cellulose aqueous dispersion) as the coating material. The effects of coating (process/formulation) on the in vitro release of coating microcapsule were evaluated via single factor investigation and orthogonal design optimization. The CH-MC with optimized formulation was further dispersed in a suitable medium to obtain a sustained-release suspension. Rats were given commercial CH ordinary tablets and the CH sustained-release suspension via intragastric administration. The plasma concentration-time curve and related pharmacokinetic parameters were investigated using the non-compartment model.

RESULTS

The T_max of the CH sustained-release suspension was delayed from 2 h to 5 h compared with the CH ordinary tablets. Similarly, the C_max was reduced from 32.138 µg·mL^-1 to 18.150 µg·mL^-1 with the concentration-time curve being more gentle compared with the commercially CH ordinary tablets. After oral administration, the relative bioavailability of CH sustained-release suspension (AUC_0-24 of 137.703 µg·h·mL^-1) to its CH ordinary tablets (AUC_0-24 of 123.337 µg·h·mL^-1) was 111.65%.

CONCLUSIONS

The findings showed that the CH sustained-release suspension for oral administration was successfully formulated.

Colon Targeting of Naringin for Enhanced Cytoprotection Against Indomethacin-Induced Colitis in Rabbits

Background

Naringin is a promising anti-inflammatory drug against various disorders including ulcerative colitis. However, its oral bioavailability is low (8%) possibly due to cleavage at the upper gut. Consequently, colon targeting would be necessary for drug protection at the upper gut, enhanced oral bioavailability and potentiated cytoprotection against colitis.

Methodology

This study involved the formulation of compression-coated tablets of naringin employing mixtures of pH-sensitive Eudragit L100-55 (EUD-L100-55) and different time-dependent polymers including ethyl cellulose (EC), sodium alginate (ALG) and sodium carboxymethyl cellulose (SCMC). Drug-polymer interaction during release was assessed using Fourier transform-infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC). Tablets were evaluated in vitro. Surface morphology of the optimized tablets either before or after exposure to the different release media was examined employing scanning electron microscopy (SEM). Cytoprotection potential of the optimized tablets against indomethacin-induced colitis in rabbits was screened and compared to core tablets through a histopathological examination of colon, measurement of serum perinuclear antineutrophil cytoplasmic antibodies (pANCA) and immunohistochemical localization of tumor necrosis factor-alpha (TNF-α).

Results

FT-IR and DSC results may indicate drug-polymers interaction during release. Release retardation could be related to polymer swelling that was in the order of SCMC > ALG > EC. SEM examination indicated more porous coats at the buffers relative to the acidic medium. Colon targeting was expected in case of coats of 5% ALG, 5% SCMC and 10% EC (w/w) in combination with EUD-L100-55; thus, they were selected for in vivo evaluation. Effective cytoprotection of selected tablets against indomethacin-induced colitis was indicated by a significant (P<0.05) reduction in mucosal damage, serum levels of pANCA and TNF-α expression compared to untreated colitis and core-pretreated groups. Compared to EC, higher cytoprotection potential of ALG- and SCMC-based tablets was reflected by lower concentration (5% w/w) to provide cytoprotection against indomethacin-induced colitis.

Design and application of oral colon administration system

Oral colon administration system has become a new method to treat intestinal diseases. The implementation of colon drug delivery system is restricted by many aspects, including physical and chemical properties, drug delivery mode, gastrointestinal physiological factors, and so on. Delivery methods to overcome these challenges revolve around the mechanisms of drug delivery, including the use of rational dosage forms to avoid the complex pH environment, and the prevention of drug release and absorption in the upper digestive tract.

In Vitro and In Vivo Test Methods for the Evaluation of Gastroretentive Dosage Forms

More than 50 years ago, the first concepts for gastroretentive drug delivery systems were developed. Despite extensive research in this field, there is no single formulation concept for which reliable gastroretention has been demonstrated under different prandial conditions. Thus, gastroretention remains the holy grail of oral drug delivery. One of the major reasons for the various setbacks in this field is the lack of predictive in vitro and in vivo test methods used during preclinical development. In most cases, human gastrointestinal physiology is not properly considered, which leads to the application of inappropriate in vitro and animal models. Moreover, conditions in the stomach are often not fully understood. Important aspects such as the kinetics of fluid volumes, gastric pH or mechanical stresses have to be considered in a realistic manner, otherwise, the gastroretentive potential as well as drug release of novel formulations cannot be assessed correctly in preclinical studies. This review, therefore, highlights the most important aspects of human gastrointestinal physiology and discusses their potential implications for the evaluation of gastroretentive drug delivery systems.

Local delivery of macromolecules to treat diseases associated with the colon

Current treatments for intestinal diseases including inflammatory bowel diseases, irritable bowel syndrome, and colonic bacterial infections are typically small molecule oral dosage forms designed for systemic delivery. The intestinal permeability hurdle to achieve systemic delivery from oral formulations of macromolecules is challenging, but this drawback can be advantageous if an intestinal region is associated with the disease. There are some promising formulation approaches to release peptides, proteins, antibodies, antisense oligonucleotides, RNA, and probiotics in the colon to enable local delivery and efficacy. We briefly review colonic physiology in relation to the main colon-associated diseases (inflammatory bowel disease, irritable bowel syndrome, infection, and colorectal cancer), along with the impact of colon physiology on dosage form design of macromolecules. We then assess formulation strategies designed to achieve colonic delivery of small molecules and concluded that they can also be applied some extent to macromolecules. We describe examples of formulation strategies in preclinical research aimed at colonic delivery of macromolecules to achieve high local concentration in the lumen, epithelial-, or sub-epithelial tissue, depending on the target, but with the benefit of reduced systemic exposure and toxicity. Finally, the industrial challenges in developing macromolecule formulations for colon-associated diseases are presented, along with a framework for selecting appropriate delivery technologies.

Taking the lead from our colleagues in medical education: the use of images of the in-vivo setting in teaching concepts of pharmaceutical science

Despite pharmaceutical sciences being a core component of pharmacy curricula, few published studies have focussed on innovative methodologies to teach the content. This commentary identifies imaging techniques which can visualise oral dosage forms in-vivo and observe formulation disintegration in order to achieve a better understanding of in-vivo performance. Images formed through these techniques can provide students with a deeper appreciation of the fate of oral formulations in the body compared to standard disintegration and dissolution testing, which is conducted in-vitro. Such images which represent the in-vivo setting can be used in teaching to give context to both theory and experimental work, thereby increasing student understanding and enabling teaching of pharmaceutical sciences supporting students to correlate in-vitro and in-vivo processes.

A Novel Approach to Flurbiprofen Pulsatile Colonic Release: Formulation and Pharmacokinetics of Double-Compression-Coated Mini-Tablets

A significant plan is executed in the present study to study the effect of double-compression coating on flurbiprofen core mini-tablets to achieve the pulsatile colonic delivery to deliver the drug at a specific time as per the patho-physiological need of the disease that results in improved therapeutic efficacy. In this study, pulsatile double-compression-coated tablets were prepared based on time-controlled hydroxypropyl methylcellulose K100M inner compression coat and pH-sensitive Eudragit S100 outer compression coat. Then, the tablets were evaluated for both physical evaluation and drug-release studies, and to prove these results, in vivo pharmacokinetic studies in human volunteers were conducted. From the in vitro drug-release studies, F6 tablets were considered as the best formulation, which retarded the drug release in the stomach and small intestine (3.42 ± 0.12% in 5 h) and progressively released to the colon (99.78 ± 0.74% in 24 h). The release process followed zero-order release kinetics, and from the stability studies, similarity factor between dissolution data before and after storage was found to be 88.86. From the pharmacokinetic evaluation, core mini-tablets producing peak plasma concentration (C max) was 14,677.51 ± 12.16 ng/ml at 3 h T max and pulsatile colonic tablets showed C max = 12,374.67 ± 16.72 ng/ml at 12 h T max. The area under the curve for the mini and pulsatile tablets was 41,238.52 and 72,369.24 ng-h/ml, and the mean resident time was 3.43 and 10.61 h, respectively. In conclusion, development of double-compression-coated tablets is a promising way to achieve the pulsatile colonic release of flurbiprofen.

Formulation Development and Characterization of Meclizine Hydrochloride Sublimated Fast Dissolving Tablets

The intention of present research is to formulate and develop the meclizine hydrochloride fast dissolving tablets using sublimation method to enhance the dissolution rate. In this study an attempt was made to fasten the drug release from the oral tablets by incorporating the superdisintegrants and camphor as sublimating agent. The prepared fast dissolving tablets were subjected to precompression properties and characterized for hardness, weight variation, friability, wetting time, water absorption ratio, and disintegration time. From in vitro release studies, the formulation F9 exhibited fast release profile of about 98.61% in 30 min, and disintegration time 47 sec when compared with other formulations. The percent drug release in 30 min (Q 30) and initial dissolution rate for formulation F9 was 98.61 ± 0.25%, 3.29%/min. These were very much higher compared to marketed tablets (65.43 ± 0.57%, 2.18%/min). The dissolution efficiency was found to be 63.37 and it is increased by 1.4-fold with F9 FDT tablets compared to marketed tablets. Differential scanning calorimetry and Fourier transform infrared spectroscopy studies revealed that there was no possibility of interactions. Thus the development of meclizine hydrochloride fast dissolving tablets by sublimation method is a suitable approach to improve the dissolution rate.

Formulation and pharmacokinetics of gelucire solid dispersions of flurbiprofen

CONTEXT

Development of solid dispersions is to improve the therapeutic efficacy by increasing the drug solubility, dissolution rate, bioavailability as well as to attain rapid onset of action.

OBJECTIVE

The present research deals with the development of solid dispersions of flurbiprofen which is poorly water soluble to improve the solubility and dissolution rate using gelucires.

MATERIALS AND METHODS

In this study, solid dispersions were prepared following solvent evaporation method using gelucire 44/14 and gelucire 50/13 as carriers in different ratios. Then the formulations were evaluated for different physical parameters, solubility studies, DSC, FTIR studies and in vitro dissolution studies to select the best formulation that shows rapid dissolution rate and finally subjected to pharmacokinetic studies.

RESULTS AND DISCUSSION

From the in vitro dissolution study, formulation F3 showed the better improvement in solubility and dissolution rate. From the pharmacokinetic evaluation, the control tablets produced peak plasma concentration (Cmax) of 9140.84 ± 614.36 ng/ml at 3 h Tmax and solid dispersion tablets showed Cmax = 11 445.46 ± 149.23 ng/ml at 2 h Tmax. The area under the curve for the control and solid dispersion tablets was 31 495.16 ± 619.92 and 43 126.52 ± 688.89 ng h/ml and the mean resident time was 3.99 and 3.68 h, respectively.

CONCLUSION

From the above results, it is concluded that the formulation of gelucire 44/14 solid dispersions is able to improve the solubility, dissolution rate as well as the absorption rate of flurbiprofen than pure form of drug.

Pharmacokinetics of colon-specific pH and time-dependent flurbiprofen tablets

Present research deals with the development of compression-coated flurbiprofen colon-targeted tablets to retard the drug release in the upper gastro intestinal system, but progressively release the drug in the colon. Flurbiprofen core tablets were prepared by direct compression method and were compression coated using sodium alginate and Eudragit S100. The formulation is optimized based on the in vitro drug release study and further evaluated by X-ray imaging and pharmacokinetic studies in healthy humans for colonic delivery. The optimized formulation showed negligible drug release (4.33 ± 0.06 %) in the initial lag period followed by progressive release (100.78 ± 0.64 %) for 24 h. The X-ray imaging in human volunteers showed that the tablets reached the colon without disintegrating in the upper gastrointestinal tract. The C max of colon-targeted tablets was 12,374.67 ng/ml at T max 10 h, where as in case of immediate release tablets the C max was 15,677.52 ng/ml at T max 3 h, that signifies the ability of compression-coated tablets to target the colon. Development of compression-coated tablets using combination of time-dependent and pH-sensitive approaches was suitable to target the flurbiprofen to colon.

Ketorolac tromethamine - routes and clinical implications

Opioids have long been used for analgesic purposes for a wide range of procedures. However, the binding of these drugs to opiate receptors has created various challenges to the clinician due to unfavorable side effect profiles and the potential for tolerance and abuse. In 1989, ketorolac became an approved nonsteroidal inflammatory drug (NSAID) for injectable use as an analgesic. Over the last 20 years, numerous studies have been conducted involving ketorolac. These studies have provided additional information about various routes of administration and their effect on the efficacy and the side effect profile of ketorolac. Moreover, ketorolac has been compared with several widely used analgesics. This review evaluates both the potential benefits and potential drawbacks of ketorolac generally, and specifically discusses routes of administration, including their advantages and disadvantages when compared to several traditional analgesics in both inpatient and outpatient settings.

Colon targeted guar gum compression coated tablets of flurbiprofen: formulation, development, and pharmacokinetics

The rationale of the present study is to formulate flurbiprofen colon targeted compression coated tablets using guar gum to improve the therapeutic efficacy by increasing drug levels in colon, and also to reduce the side effects in upper gastrointestinal tract. Direct compression method was used to prepare flurbiprofen core tablets, and they were compression coated with guar gum. Then the tablets were optimized with the support of in vitro dissolution studies, and further it was proved by pharmacokinetic studies. The optimized formulation (F4) showed almost complete drug release in the colon (99.86%) within 24 h without drug loss in the initial lag period of 5 h (only 6.84% drug release was observed during this period). The pharmacokinetic estimations proved the capability of guar gum compression coated tablets to achieve colon targeting. The C_max of colon targeted tablets was 11956.15 ng/mL at T_max of 10 h whereas it was 15677.52 ng/mL at 3 h in case of immediate release tablets. The area under the curve for the immediate release and compression coated tablets was 40385.78 and 78214.50 ng-h/mL and the mean resident time was 3.49 and 10.78 h, respectively. In conclusion, formulation of guar gum compression coated tablets was appropriate for colon targeting of flurbiprofen.