Quality by design (QbD) approach for design and development of drug-device combination products: a case study on flunisolide nasal spray.

The objective of the present study was to design and develop drug-device combination product in particular flunisolide nasal spray (FNS) using quality by design (QbD) approach. Quality target product profile (QTPP) of FNS was defined and critical quality attributes (CQAs), i.e. viscosity (cp) (Y1) and D50 droplet size distribution (DSD) (µm) (Y2) were identified. Potential risk factors were identified using a fish bone diagram and failure mode effect analysis (FMEA) tools. Plackett-Burman and Box-Behnken designs were used for screening the significant factors and optimizing the variables range, respectively. It was observed that viscosity (cp) (Y1) was significantly impacted by formulation variables X1: propylene glycol (PG) (%) and X2: polyethylene glycol (PEG) 3350 (%), while D50 DSD (µm) (Y2) was significantly impacted by formulation variables X1: PG (%), X2: PEG 3350 (%) and device variable X8: delivery volume (µl). A design space plot within which the CQAs remained unchanged was established at laboratory scale. In conclusion, this study demonstrated how QbD based development approach can be applied to the development of drug-device combination products with enhanced understanding of the impact of formulation, process and device variables on CQAs of drug-device combination products.

Quality by design approach for development of suspension nasal spray products: a case study on budesonide nasal suspension.

The objective of this study was to provide quality by design (QbD) approach for development of suspension type nasal spray products. Quality target product profile (QTPP) of test product budesonide nasal suspension (B-NS) was defined and critical quality attributes (CQAs) were identified. Critical formulation, process and delivery device variables were recognized. Risk assessment was performed by using failure mode and effect analysis (FMEA) methodology. Selected variables were further assessed using a Plackett Burman screening study. A response surface design consisting of the critical factors was used to study the interactions between the study variables. Formulation variable X2: median particle size of budesonide (D50) (µ) has strikingly influenced dissolution (%) (Y1), while D50 droplet size distribution (µm) (Y2) was significantly impacted by formulation variable X1: Avicel RC 591 (%) and process variable X4: homogenization speed (rpm). A design space plot within which the CQAs remained unchanged was established at lab scale. A comprehensive approach for development of B-NS product based on the QbD methodology has been demonstrated. The accuracy and robustness of the model were confirmed by comparability of the predicted value generated by model with the observed value.

Assessment of isomalt for colon-specific delivery and its comparison with lactulose.

Lactulose is used as a triggering substance in a unique colon-specific delivery technology called CODESTM. Colonic microflora degrades lactulose and forms short-chain fatty acids to activate the CODESTM system. However, lactulose has been reported to cause a Maillard-type reaction with substances containing primary or secondary amino groups that may produce carcinogenic compounds. Thus, the aim of this study was to look into the possibility to substitute lactulose with isomalt for fabrication of CODESTM. The in vitro degradation of both sugars before incorporating them into the CODESTM system was evaluated with the help of rat caecal microflora. The results showed that isomalt was less efficient with regard to its rate and extent of degradation into short-chain fatty acids by the microflora compared to lactulose. However, the in vitro dissolution study did not show a significant difference in the performance between lactulose and isomalt when they were incorporated separately in CODESTM. A similar result was also obtained in the in vivo study. Based on the above results, isomalt could be used as an alternative to lactulose for colonic delivery system utilizing the principles of CODESTM.

Enhanced bioavailability of atorvastatin calcium from stabilized gastric resident formulation.

Oral bioavailability of atorvastatin calcium (ATC) is very low (only 14%) due to instability and incomplete intestinal absorption and/or extensive gut wall extraction. When ATC is packed in the form of tablets, powders, etc., it gets destabilized as it is exposed to the oxidative environment, which is usually present during the production process, the storage of the substance, and the pharmaceutical formulation. Therefore, stabilized gastro-retentive floating tablets of ATC were prepared to enhance bioavailability. Water sorption and viscosity measurement studies are performed to get the best polymer matrix for gastro-retention. A 3(2) factorial design used to prepare optimized formulation of ATC. The selected excipients such as docusate sodium enhanced the stability and solubility of ATC in gastric media and tablet dosage form. The best formulation (F4) consisting of hypromellose, sodium bicarbonate, polyethylene oxide, docusate sodium, mannitol, crosscarmellose sodium, and magnesium stearate, gave floating lag time of 56 ± 4.16 s and good matrix integrity with in vitro dissolution of 98.2% in 12 h. After stability studies, no significant change was observed in stability, solubility, floating lag time, total floating duration, matrix integrity, and sustained drug release rates, as confirmed by DSC and powder X-ray diffraction studies. In vivo pharmacokinetic study performed in rabbits revealed enhanced bioavailability of F4 floating tablets, about 1.6 times compared with that of the conventional tablet (Storvas® 80 mg tablet). These results suggest that the gastric resident formulation is a promising approach for the oral delivery of ATC for improving bioavailability.

Enhanced Bioavailability and Dissolution of Atorvastatin Calcium from Floating Microcapsules using Minimum Additives.

Atorvastatin calcium, a lipid-lowering drug, is much less bioavailable because of reduced solubility in acidic media. Multiple-unit floating microcapsules of Atorvastatin calcium (ATC) were developed to expand the gastric residence time of the drug, as ATC has maximum rate of absorption in the upper GI tract. Floating microcapsules were prepared by Emulsion-solvent evaporation technique through incorporation of dioctyl sodium sulphosuccinate (DSS) as a dissolution enhancer. The microcapsules were assessed for shape, size, drug entrapment efficiency, stability and in-vitro drug dissolution rate and were subjected to SEM, DSC and PXRD studies. The ATC-loaded floating microcapsules were spherical in shape and had the particle size of about 28.10 µm and drug-loading efficiency of about 96.55 %. The floating microspheres containing DSS had significantly higher drug dissolution rates than those without DSS. The best formulation, AT4, consisting of Ethyl cellulose, DSS and Poly Ox®, had a maximum drug dissolution rate of 97.86 %, as compared to Storvas 80 mg (Ranbaxy Ltd, as a reference) which had a rate of only 54% during a period of 12 h in acidic media. A pharmacokinetic study performed on albino rabbits illustrates that the bioavailability of AT4 floating microcapsules significantly increased to nearly 1.7 times that of Storvas 80 mg. The present study indicates that the use of multi-unit floating microcapsules for delivery of ATC can improve its bioavailability.