Application of the BCS biowaiver approach to assessing bioequivalence of orally disintegrating tablets with immediate release formulations

Pharmacodynamics Research on Danggui-Shaoyao-San through Body Fluid Indexes of Spleen Deficiency-water Dampness Rats using Bio-impedance Technology

BACKGROUND

Spleen deficiency-water dampness symptom is closely related to body fluid-mediated organism metabolism and circulation. However, previous clinical evaluation of spleen deficiency-water dampness model was based only on body weight, D-xylose excretion rate, serum gastrin content, etc. Therefore, we established a large sample of normal rats and model rats experiment to verify the scientific nature of bio-impedance measuring body fluid indexes for evaluation of the modeling state. Pharmacodynamics research on Danggui-Shaoyao- San (DSS) was conducted through body fluid index changes of rats using bio-impedance technology.

METHODS

A spleen deficiency-water dampness symptom rat model was established through an inappropriate diet combined with excess fatigue. Experimental rats were divided into a normal control group, a model control group, a positive drug control group (hydrochlorothiazide), a blood-activating group, a water-disinhibiting group, and a DSS group. Total Body Water/Body Weight (TBW%), extracellular fluid/total body water content (ECF%), intracellular fluid/total body water content (ICF%), extracellular fluid/intracellular fluid (ECF/ICF), fat mass/body weight (FM%), fat-free mass/body weight (FFM%), and fat mass/fat-free mass (FM/FFM) of 150 rats were detected by a Bio-Imp Vet Body analyzer.

RESULTS

The TBW% of the model control group increased significantly, and the FM/FFM was significantly reduced compared with the normal group (P < 0.05) (P < 0.01), showing symptoms of spleen deficiency and diarrhea; the TBW% of the blood-activating group, and the waterdisinhibiting group decreased significantly, and the FM/FFM increased significantly (P < 0.05) (P < 0.01). The TBW% and FM/FFM in the water-disinhibiting group had returned to nearnormal values compared with the model control group. The blood-activating and waterdisinhibiting split prescriptions in DSS are both effective in treating spleen deficiency-water dampness rats. Comparatively, the fluid-regulating effect of split prescriptions in DSS was even stronger than that of DSS as shown in the present study.

CONCLUSIONS

These findings suggest that using bio-impedance technology to measure body fluid indexes can pave a road for further exploring the molecular mechanism of the reason why the blood-activating and disinhibit-water split prescriptions in DSS are both effective in treating spleen deficiency-water dampness rats.

Investigating the Impact of Co-processed Excipients on the Formulation of Bromhexine Hydrochloride Orally Disintegrating Tablets (ODTs)

PURPOSE

Orodispersible tablets (orally disintegrating tablets, ODTs) have been used in pharmacotherapy for over 20 years since they overcome the problems with swallowing solid dosage forms. The successful formula manufactured by direct compression shall ensure acceptable mechanical strength and short disintegration time. Our research aimed to develop ODTs containing bromhexine hydrochloride suitable for registration in accordance with EMA requirements.

METHODS

We examined the performance of five multifunctional co-processed excipients, i.e., F-Melt® C, F-Melt® M, Ludiflash®, Pharmaburst® 500 and Prosolv® ODT G2 as well as self-prepared physical blend of directly compressible excipients. We tested powder flow, true density, compaction characteristics and tableting speed sensitivity.

RESULTS

The manufacturability studies confirmed that all the co-processed excipients are very effective as the ODT formula constituents. We noticed superior properties of both F-Melt's®, expressed by good mechanical strength of tablets and short disintegration time. Ludiflash® showed excellent performance due to low works of plastic deformation, elastic recovery and ejection. However, the tablets released less than 30% of the drug. Also, the self-prepared blend of excipients was found sufficient for ODT application and successfully transferred to production scale. Outcome of the scale-up trial revealed that the tablets complied with compendial requirements for orodispersible tablets.

CONCLUSIONS

We proved that the active ingredient cannot be absorbed in oral cavity and its dissolution profiles in media representing upper part of gastrointestinal tract are similar to marketed immediate release drug product. In our opinion, the developed formula is suitable for registration within the well-established use procedure without necessity of bioequivalence testing.

Bioequivalence Dissolution Test Criteria for Formulation Development of High Solubility-Low Permeability Drugs

The purpose of the present study was to provide the experimental and theoretical basis of bioequivalence (BE) dissolution test criteria for formulation development of high solubility-low permeability drugs. According to the biowaiver scheme based on the biopharmaceutics classification system (BCS), for BCS class III drugs, a test formulation and a reference formulation are predicted to be BE when 85% of the drug dissolves within 15 min (T_85% < 15 min) in the compendial dissolution test. However, previous theoretical simulation studies have suggested that this criterion may possibly be relaxed for use in practical formulation development. In the present study, the dissolution profiles of 14 famotidine formulations for which BE has been clinically confirmed were evaluated by the compendial dissolution test at pH 1.2 and 6.8. The plasma concentration-time profiles of famotidine formulations were simulated using the dissolution data. In addition, virtual simulations were performed to estimate the range of dissolution rates to be bioequivalent. The fastest and slowest dissolution rates among the famotidine formulations were T_85% = 10 min and T_85% = 60 min at pH 6.8, respectively. The virtual simulation BE study suggested that famotidine formulations can be bioequivalent when T_85% < 99 min. In the case of BCS III drugs, the rate-limiting step of oral drug absorption is the membrane permeation process rather than the dissolution process. Therefore, a difference in the dissolution process has less effect on BE. These results contribute to a better understanding of the biowaiver approach and would be of great help in the formulation development of BCS class III drugs.

Efficient Evaluation of In Vivo Performance in Human for Generic Formulation by Novel Dissolution-Absorption Prediction (DAP) Workflow

PURPOSE

The pharmaceutical bioequivalence of generic medicines must be confirmed with corresponding original drugs. Although the in vitro dissolution tests are required, results of the mandatory in vitro study do not necessarily reflect the in vivo performance after oral administration. Then, we have tried to develop the novel "Dissolution-Absorption Prediction (DAP) workflow" to evaluate the in vivo performance of generic medicines.

METHODS

The DAP workflow consists of an "In vitro two-cell connected dissolution (TCCD) system" mimicking the changes in the luminal pH associated with gastrointestinal transit of medicines, "Evaluation of pharmacokinetics of active pharmaceutical ingredient (API)" and "Prediction of plasma concentration-time profile". TCCD system-evaluated dissolution kinetics of APIs from generic formulations and pharmacokinetic parameters based on human data regarding the original drugs were used to calculate the plasma concentration-time profiles of APIs after the oral administration of generic medicines.

RESULTS

The mandatory in vitro dissolution tests indicated that the dissolution properties of valsartan (BCS class II) and fexofenadine (BCS class III/IV) in generic formulations did not coincide with those in the corresponding original formulations. The TCCD system provided the very similar dissolution kinetics for the generic and original formulations for the two APIs. Plasma concentration-time profiles evaluated utilizing the dissolution profiles obtained by the TCCD system were in good agreement with the observed profiles for both the generic and original formulations for each API.

CONCLUSIONS

The DAP workflow would be valuable for estimating the in vivo performance of generic formulation and deducing their bioequivalence with the original formulation.

Maraviroc Oral Disintegration Tablet: Analytical Design of Experiments (DoE) for Assessment and Comparison of In-Vitro Dissolution Profiles

Background:

The bioavailability of a drug in a solid oral dose depends on its release from the drug product and its balance in dissolution. Compared with a reference drug, the newly developed formulation needs to establish bioequivalence by comparing the dissolution profile.

Objective:

To compare dissolution profiles of a newly developed maraviroc oral disintegration tablet and the reference Axentri® tablet. The current research was designed to establish and validate an integral analytical consistency by Quality by Design (QbD) approach to quantify maraviroc from dissolution samples using the RP-HPLC method.

Methods:

Maraviroc was formulated into an orally disintegrating tablet using a direct compression technique at different concentrations of sodium starch glycolate as super disintegrants and talc and magnesium stearate as glidants. The dissolution test in 0.1N HCl was performed according to standard procedures to predict bioequivalence. The results of dissolution tests were analyzed using the QbD Box Behnken Design multivariate RP-HPLC method.

Results:

The optimized formulation (F2) was selected as it showed 90% drug release in 5 min and a disintegration time of 22 sec with dissolution profiles to the marketed reference to meet the FDA requirements of f2 similarity factor statistics. The integrated analytical QbD method was statistically analyzed by ANOVA, counter-plot, and 3D response surface plots, which demonstrated that the model is statistically significant. The developed method was validated as per ICH guidelines Q2 (R1).

Conclusion :

In conclusion, maraviroc oral disintegrating tablets have been well prepared, and superior statement consistency is established by the implementation of the QbD analytical method for orally disintegrating tablet excellence and adoption.

Formulation of olopatadine hydrochloride viscous eye drops - physicochemical, biopharmaceutical and efficacy assessment using in vitro and in vivo approaches

The aim of this work was the formulation and the comprehensive evaluation of the viscous eye drops using vehicles containing medium chain chitosan (0.5% w/v), hydroxypropyl guar gum (0.25% w/v) and their combination as carriers for olopatadine (0.1% w/v). Physicochemical properties (appearance, clarity, pH, osmolality, viscosity and drug content) of the tested formulations were within acceptable ranges for the ophthalmic preparations, while DSC and FT-IR techniques demonstrated the compatibility between olopatadine and polymers. The drug permeability was successfully estimated in vitro using both HCE-T cell-based models (Model I and Model II) and the parallel artificial membrane permeability assay (PAMPA), considering the impact of chitosan as a permeation enhancer. The MTT cytotoxicity assay demonstrates that the tested formulations (diluted 10-fold in HBSS pH 5.5) were non-toxic and well tolerated. An ocular itch test on mice was carried out with the formulation containing the combination of polymers comparable with a commercially available olopatadine eye drops without viscosity enhancers. The tested eye drops produced a slightly higher anti-pruritic/analgesic-like effect than the commercial preparation. It could be assumed that the use of this viscous ophthalmic vehicle due to its advanced mucoadhesive properties and good safety profile is a feasible strategy to improve the efficacy of olopatadine.

Medicines for Pediatric Patients-Biopharmaceutical, Developmental, and Regulatory Considerations

This commentary reflects current developments in pediatric medicine. The underpinning legislation in both Europe and the United States has led to the initiation of an increased number of clinical trials in the pediatric population, but there are still a number of outstanding issues within this field. These include the differences in the physiology between adults and the very heterogeneous nature of pediatric patients. There is an ongoing scientific debate on the applicability of a Pediatric Biopharmaceutical Classification System to define when waivers for bioequivalence studies can be supported by in vitro dissolution. However, a challenge is that in vitro models should adequately mimic the physiology of different pediatric age-groups and dose definition is another critical aspect. There is a tendency for off-label use of established adult medicines, resulting in increased adverse events and decreased efficacy in the target population. Recent advances in physiologically based pharmacokinetic modelling may be used to provide valuable input into these discussions, but there are currently still many knowledge gaps. It is encouraging that there is a global recognition of these deficiencies and substantial funding in the field of basic research is being provided, for example, within Europe the Innovative Medicines Initiative consortium.