Similarity of dissolution profiles from biorelevant media: Assessment of interday repeatability, interanalyst repeatability, and interlaboratory reproducibility using ibuprofen and ketoconazole tablets

Application of bootstrap f2 to dissolution data from biorelevant media and evidence of the conservative nature of bootstrap f2

f2 with or without bootstrapping is the most common method to compare in vitro dissolution profiles, but methods to compare dissolution profiles have become less harmonized. The objective was to compare outcomes from bootstrap f2 and f2 (i.e. not-bootstrapped f2) using a large set of in vitro dissolution data. Non-parametric bootstrapping was performed on the 104 profile comparisons that did not meet the percent coefficient of variation (CV%) criteria to use average dissolution data. Bootstrap f2 was taken as the lower 90 % confidence interval of bootstrapped samples. There was concordance between bootstrap f2 and f2 in 92 of the 104 comparisons (88 %). There were no false positives. However, 12 % were false negative. Inspection of these discordance pairs suggests that bootstrap f2 serves as a conservative approach to assess profile similarity, particularly when a value of 50 is being used as decision criteria.

A novel theoretical strategy for predicting dissolution kinetics and mechanisms of pharmaceuticals in complex biorelevant media

The influence mechanism of biorelevant media on the dissolution of active pharmaceutical ingredients (APIs) is the key to their formulation design. The dissolution kinetics of naproxen (NAP) and indomethacin (IND) in biorelevant media was systematically investigated. The dissolution mechanism was analyzed by chemical potential gradient model to explore the influence of surfactant type, pH and ionic strength. Hexadecyl trimethyl ammonium bromide (CTAB) is superior to sodium dodecyl sulfate (SDS) in promoting the dissolution of NAP and IND by increasing the solubility and accelerating the surface reaction processes. The electrostatic repulsion between SDS and NAP and IND with the same negative charge facilitates the diffusion of API, while the mutual attraction between CTAB and NAP and IND is not conducive to diffusion. High pH was favorable for the dissolution of acidic NAP and IND, as the simultaneous increase in solubility, surface reaction constant, and diffusion constant. High ionic strength was beneficial for the surface reaction of NAP and IND, but hindered their diffusion. It was shown that the modeling results were in conformity with the in vitro experimental data. These results are expected to provide theoretical supports for the design of biorelevant media and pharmaceutical formulations in the pharmaceutical development.

Ternary system of sultamicillin tosylate with hydroxypropyl-β-cyclodextrin and L-arginine: susceptibility against methicillin-resistant Staphylococcus aureus

Aim: This study investigated the effect of complex formation between sultamicillin tosylate (ST), hydroxypropyl-β cyclodextrin (HP-βCD) and L-arginine (ARG). Materials & methods: The kneading method was used to prepare the complexes, which were then characterized using SEM, DSC, FT-IR, HPLC, saturation solubility and dissolution studies. The complexes' antibacterial activity against MRSA (ATCC^®-43300TM) was evaluated using ZOI and MIC. Results: Solubility was enhanced in the binary and ternary complexes compared with ST (p < 0.001). MIC and ZOI showed that both complexes have increased antibacterial activity compared with ST (p < 0.001) against MRSA. Conclusion: As a result, the inclusion complex of ST with HP-βCD and ARG can be used to improve the physicochemical properties of ST while also improving antibacterial efficacy against MRSA infections.

A Simple One-Parameter Percent Dissolved Versus Time Dissolution Equation that Accommodates Sink and Non-sink Conditions via Drug Solubility and Dissolution Volume

In vitro dissolution generally involves sink conditions, so dissolution equations generally do not need to accommodate non-sink conditions. Greater use of biorelevant media, which are typically less able to provide sink conditions than pharmaceutical surfactants, necessitates equations that accommodate non-sink conditions. One objective was to derive an integrated, one-parameter dissolution equation for percent dissolved versus time that accommodates non-sink effects via drug solubility and dissolution volume parameters, including incomplete solubility. A second objective was to characterize the novel equation by fitting it to biorelevant dissolution profiles of tablets of two poorly water-soluble drugs, as well as by conducting simulations of the effect of dose on dissolution profile. The Polli dissolution equation was derived, [Formula: see text], where M₀ is the drug dose (mg), c_s is drug solubility (mg/ml), V is dissolution volume (ml), and k_d is dissolution rate coefficient (ml/mg per min). Maximum allowable percent dissolved was determined by drug solubility and not a fitted extent of dissolution parameter. The equation fit tablet profiles in the presence and absence of sink conditions, using a single fitted parameter, k_d, and where solubility ranged over a 1000-fold range. k_d was generally smaller when c_s was larger. FeSSGF provided relatively small k_d values, reflecting FeSSGF colloids are large and slowly diffusing. Simulations showed impact of non-sink conditions, as well as plausible k_d values for various c_s scenarios, in agreement with observed k_d values. The equation has advantages over first-order and z-factor dissolution rate equations. An Excel file for regression is provided.

Characterization of Dissolution-Permeation System using Hollow Fiber Membrane Module and Utility to Predict in Vivo Drug Permeation Across BCS Classes

A dissolution-permeation system has potential to provide insight into the kinetic contributions of dissolution and permeation to overall drug absorption. The goals of the study were to characterize a dissolution-hollow fiber membrane (D-HFM) system and compare its resulting in vitro drug permeation constants (K_p^') to in vivo clinical permeation constants (k_p), for four drugs in various Biopharmaceutics Classification System (BCS) classes. Model predictions for D-HFM were made based on derived mixing tank (MT) and complete radial (CRM) flow models and independent measurement of membrane permeability. Experimental D-HFM studies included donor flow rate and donor volume sensitivity studies, and drug permeation profile studies. Additionally, for the four drugs, K_p^'from D-HFM system was compared to (k_p) from literature, as well as K_p^' values from side-by-side diffusion cell and dissolution/Caco-2 system. Results show progressive D-HFM system development as a dissolution-permeation tool. Results indicated that D-HFM models using MT or CRM provided close agreement between predicted and observed drug permeation profiles. Drug permeation in D-HFM system was volume dependent, as predicted. Favorably, more drug permeated through the D-HFM system (10-20% in 60 min) compared to side-by-side diffusion cell (1%) and dissolution/Caco-2 system (0.1%). K_p^' from D-HFM system was also closer to in vivo k_p; the two other in vitro models showed lower K_p^'. Overall, studies reflect that HFM module has potential to incorporate drug permeation into the in vitro assessment of in vivo tablet and capsule performance.

Prediction of In Vitro Drug Dissolution into Fed-state Biorelevant Media: Contributions of Solubility Enhancement and Relatively Low Colloid Diffusivity

A model was previously derived to predict in vitro dissolution of drug into surfactant solution and showed good predictability for pharmaceutical surfactants, where surfactant-mediated enhanced drug dissolution was several fold less than enhanced solubility (about 3-fold or less) due to drug-loaded micelles exhibiting slower diffusivity than free drug. The present objective was to quantitatively assess the contributions of biorelevant media-mediated solubility and diffusivity on enhanced drug dissolution in FeSSGF and FeSSIF-V2. Three poorly water soluble drugs were subjected to dissolution into FeSSGF and FeSSIF-V2, as well as their corresponding "surfactant-free" media. Solubility and laser diffraction analysis of drug in FeSSGF and dynamic light-scattering studies (DLS) of drug in FeSSIF-V2 were conducted. Results showed drug-saturated FeSSGF globules and FeSSIF-V2 mixed micelles were large and slow diffusing (diffusivities of about 1×10^-9 and 7×10^-8 cm²/s, respectively), compared to free drug (about 7×10^-6 cm²/s) and drug-bound micelles from pharmaceutical surfactants (about 0.5-1×10^-6 cm²/s). Of the three drugs, griseofulvin exhibited the greatest biorelevant media-enhanced solubility and dissolution (652-fold and 6.23-fold respectively in FeSSGF, and 190-fold and 12.7-fold respectively in FeSSIF-V2), but slow colloid diffusivity markedly attenuated large solubility benefits, particularly in FeSSGF.

Understanding the Impact of Multi-factorial Composition on Efficient Loading of the Stable Ketoprofen Nanoparticles on Orodispersible Films Using Box-Behnken Design

The purpose of the present study was to prepare Orodispersible films (ODFs) loaded with ketoprofen nanoparticles (KT-NP). The Box-Behnken design was constructed in developing and optimizing the KTF-NP-ODFs. The effect of independent variables: Soluplus® concentration (X₁, stabilizer), Tween 80 concentration (X₂, surfactant), and KTF concentration (X₃, drug) were studied on the dependent variables: particle size (PS, Y₁), zeta potential (ZP, Y₂), and the polydispersity index (PDI, Y₃) of the NPs, as well as on the tensile strength (TS, Y₄) and permeability coefficient (PC, Y₅) of the KTF-NP-ODFs. Hydroxypropyl methylcellulose (HPMC E15) and polyethylene glycol (PEG 400) were used as the film former polymer and plasticizer, respectively, and their concentrations were kept constant for all formulations. KTF-NPs were prepared by antisolvent precipitation technology. This was followed by the addition of HPMC E15 and PEG 400 to prepare the ODFs using the solvent-casting method. The PS, PDI, and ZP for all the formulations were found in the range of 94 nm to 350 nm, 0.09 to 0.438, and -21.83 mV to -8.03 mV, respectively. The TS and PC of the prepared KTF-NP-ODFs were found between 1.21 MPa to 3.93 MPa and 3.12 × 10^-4 cm/h to 34.23 × 10^-4 cm/h, respectively. The amorphous nature of the KTF-NP in the ODFs was confirmed by the absence of characteristic crystalline peaks and endothermic events of KTF in X-ray diffraction (XRD) and modulated differential scanning calorimetry (mDSC), respectively. The optimized formulation showed ̴ 4 times higher permeability as compared to the pure KTF. In addition, the dissolution of pure KTF and the optimized KTF-NP-ODF in pH 1.2 at the end of 60 min was found to be ̴ 30% and ̴ 95%, respectively. Conclusively, KTF-NP-ODFs can be a promising drug delivery system to counter the issues related to dysphagia and bypass the common side effects, such as the gastric irritation associated with NSAIDs like KTF.

Mucoadhesive microspheres of glutaraldehyde crosslinked mucilage of Isabgol husk for sustained release of gliclazide

Mucoadhesive microspheres have their own significant amongst the various sustained release drug delivery systems. The prolonged residence time of these delivery devices at drug absorption site results in steep concentration gradient and enhanced bioavailability. In this study, the mucilage of Isabgol husk was applied as polymeric backbone to develop gliclazide loaded microspheres by crosslinking with glutaraldehyde. The formulations were studied for surface morphology, swelling behavior, particle size, in vitro release, release kinetics, in vitro mucoadhesion and gamma scintigraphy in rabbits. The release of gliclazide from microspheres was controlled by swelling of crosslinked microspheres followed by diffusion. Gamma scintigraphic images acquired for microspheres retention in gastrointestinal track of rabbits indicated the residence of formulation upto 24 h after oral administration. Gliclazide retained its integrity in polymeric matrix of microspheres as observed by Fourier transform infrared spectroscopy, differential scanning calorimetry and powder X-ray diffractometry. The sustained release of gliclazide and prolonged retention of microspheres in gastrointestinal track disclosed the rationality of mucoadhesive Isabgol husk microspheres in controlling the hyperglycemia in diabetes.