Kollicoat MAE Research Articles

3D printing of hollow capsular body & sealing pin by fused filament fabrication (FFF) technique using Kollicoat MAE 100P filament for intestinal specific delivery

3D printing of hollow capsular body & sealing pin by fused filament fabrication (FFF) technique using Kollicoat MAE 100P filament for intestinal specific delivery

Kollicoat MAE® 100P as a film former polymer for nanoparticles preparation

Introduction: Until now, few research works have reported the usefulness of Kollicoat MAE® 100P as a film-former polymer for coating nanocapsules and as a matrix former for nanospheres. Aim: To update the current knowledge about the use of Kollicoat MAE® 100P as a film-former polymeric to prepare gastro-resistant nanoparticles. Physicochemical characteristics and functionality of nanoparticles coated with Kollicoat MAE® 100P were reported. Methodology: An exhaustive review was performed (from 1980 to 2021) in various scientific databases like Medline, Scopus, EBSCO and Cambridge. Results: Kollicoat MAE® 100P is a versatile polymer that can be used to prepare gastro-resistant nanoparticles with actives of natural and synthetic origin. This polymer allows producing homogeneous nanoparticles with sizes smaller than 130 nm, and high z-potential, which confers a great stability to nanoparticle systems. On the other side, nanoparticles coated with Kollicoat MAE® 100P combined with plasticizer exhibit a hard and flexible shell, with excellent thermal stability up to 60 °C that dissolve at pH above 5.5. Conclusion: Kollicoat MAE® 100P ris a viable, low-cost, and multifunctional alternative for nanoparticle preparation, however, more studies are needed to develop enhanced nanoparticles with better performances.

Formulation and Evaluation of Kaempferol Loaded Nanoparticles against Experimentally Induced Hepatocellular Carcinoma: In Vitro and In Vivo Studies.

The present study was designed to prepare Kaempferol loaded nanoparticles (KFP-Np) and evaluate hepatoprotective and antioxidant effects in hepatocellular carcinoma models. KFP was encapsulated with hydroxypropyl methylcellulose acetate succinate (HPMC-AS) and Kollicoat MAE 30 DP polymers to prepare nanoparticles (Nps) by quasi-emulsion solvent diffusion technique (QESD). The prepared Nps were evaluated for different pharmaceutical characterization to select the optimum composition for the in vivo assessment. An animal model of cadmium chloride (CdCl2)-induced hepatocellular carcinoma in Male Sprague Dawley rats was used in vivo to test the antioxidant and hepatoprotective capacity of free and encapsulated KFP. The prepared Npsshowed nanometric size, low PDI, high drug load as well as encapsulation with a better drug release profile. There was a significant decrease in the increased serum levels of alanine transaminase (ALT), total bilirubin (TBiL), and aspartate transaminase (AST), and the lipid peroxidation’s (MDA) level was attenuated, and levels of markers of the cell antioxidant defence system were restored including Glutathione S-transferase (GST), glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) via oral pre-treatment with KFP-Np (50 mg/kg b.w. (body weight), 6 weeks). KFP-Np significantly declines an mRNA expression of interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-alpha (TNF-α) as well as decreased nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) protein expression. It also upregulated the mRNA expression and protein expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1). While comparing the protective effects of KFP encapsulated in Kollicoat MAE 30 DP and HPMC-AS, Nps was found to be betterthan free KFP. Insummary, result indicate that encapsulation of KFP in NPs provides a potential platform for oxidative stress induce liver injury.

Pharmaceutically Acceptable Carboxylic Acid-Terminated Polymers Show Activity and Selectivity against HSV-1 and HSV-2 and Synergy with Antiviral Drugs

Polyanionic macromolecules including carboxylate-terminated polymers (polycarboxylates) are capable of inhibiting sexually transmitted viruses such as human immunodeficiency virus (HIV) and herpes simplex virus (HSV). Cellulose acetate phthalate (CAP), a pharmaceutically acceptable pH-sensitive polycarboxylate polymer, showed promising prophylactic activity against HIV and HSV, but the instability of CAP in an aqueous environment prevented its clinical development. Interestingly, several pharmaceutically acceptable polycarboxylates have features similar to CAP with an aqueous stability significantly higher than that of CAP. However, their activity against sexually transmitted viruses remains unexplored. Here, we evaluate the activity of various polycarboxylates such as polyvinyl acetate phthalate (PVAP), various grades of hydroxypropyl methylcellulose phthalate (HPMCP-50, HPMCP-55, and HPMCP-55S), and various grades of methacrylic acid copolymers (Eudragit L100-55, Eudragit L100, Eudragit S100, and Kollicoat MAE 100P) against HSV. We, for the first time, demonstrate that PVAP, HPMCP-55S, and Eudragit S100 have activity and selectivity against HSV-1 and HSV-2. Further, we report that polycarboxylates can be easily transformed into nanoparticles (NPs) and in the nanoparticulate form, they show similar or enhanced activity against HSV. Finally, using PVAP NPs, as a model, we demonstrate using in vitro HSV therapy studies that polycarboxylate NPs are capable of synergizing with antiviral drugs such as acyclovir (ACV), tenofovir, and tenofovir disoproxil fumarate. Thus, pharmaceutically acceptable carboxylic acid-terminated polymers and their NPs have the potential to be developed into topical formulations for the prevention and treatment of HSV infection.

The relationship between mucoadhesive polymers and surface coating in tablets for the controlled colonic delivery of a poorly water-soluble drug.

The mucoadhesive polymers play an important role in targeted and controlled drug delivery. This study aimed to investigate the drug release behaviour and interpret the role of mucoadhesive polymers involved in the coating layer of mucoadhesive tablets for the sustained release of a poorly water-soluble drug. A solid dispersion of prednisolone and zein was used in the core tablets created with two mucoadhesive polymers, which included Carbopol 940 and hydroxypropyl methylcellulose K4M. In addition, the properties of a single-layer coating, created from the combination of zein and Kollicoat MAE 100P to delay release through the upper parts of the gastrointestinal tract, were investigated in the presence of the above mucoadhesive polymers; these properties included drug dissolution, mucoadhesion, surface morphology, swelling and erosion. The mucoadhesive polymer concentrations and types were integrated not only into the core tablets through a swelling/erosion mechanism but also into the surface polymer coatings for controlled drug release. HPMC was preferred in the formulations due to the ability to form pores on the surface coating, allowing water uptake so that the coating could control drug release for a later stage via a swelling/erosion mechanism. The proposed mechanism determined in this project could be beneficial in the selection of polymers for applications targeting the colon with coated mucoadhesive tablets. Graphical abstract.

Research and Development of the Composition and Technology Receving of Granules of Omeprazol in the Fluid Bed Apparatus

Introduction. In this research is devoted to questions of development of structure and technology of granules of an omeprazole. It is established that the most optimal dosage form for medicines of inhibitors of a proton pump is considered to be the tablet with a multiple-unit pellets system (microparticles). In this case of the production of these medicines in the microgranules of a particle are covered with several protective covers. For development of microgranules of an omeprazole is offered the technology of lamination in the fluid bed apparatus.Aim. To receive in the fluid bed apparatus of the microgranules of an omeprazole covered with the enteric cover.Materials and methods. To solve this problem technical characteristics on the granulates of an omeprazole received at various operating modes of the fluid bed apparatus are defined such as form of granules, fractional structure and bulk density are determined by the methods described by the State Pharmacopeia of the XIII edition.Results and discussion. As a result of a research the choice of polymers for layered deposition in the granulation process of a substance of omeprazole is substantiated. Produced selection of enteric polymer of various firms of producers is made for providing a necessary profile of release of an omeprazole in a human body. A copolymer of methacrylic acid – Kollicoat MAE 100 P is chosen. Special attention is paid to receiving the enteric granules of an omeprazole of the correct spherical form with minimum roughness and the improved flowability for further tabletting. For the purpose of receiving granules of an omeprazole of a spherical form selection of an optimum operating mode of the device of a fluid bed apparatus is made for implementation of process of applying the enteric polymer. Following the results of experiments the dependence of quality of fractional structure and appearance of granules of an omeprazole on temperature, pressure and feed rate of polymer is defined. Besides, it is established that the uniformity of application and thickness of a layer of the applied enteric polymer on granules of an omeprazole depend not only on the polymer feed rate, but also on the size of drops of the feed solution.Conclusion. It is established that the quality of the granules of an omeprazole received the enteric polymer was affected by such factors of technological parameters of the fluid bed apparatus as: temperature of the entering air in the apparatus, the air pressure upon a nozzle, air pressure upon a gas-distributing grid of the apparatus, speed of the given polymer, a lot of loading of granules, air temperature of a layer of granules, duration of drying of granules upon termination of process of application of the enteric polymer.

Development and evaluation of ivabradine microspheres for controlled release

The objective of this study was to formulate and evaluate controlled release formulations of ivabradine hydrochloride (HCl)-loaded microspheres consisting of Kollicoat MAE 100 P and ethyl cellulose prepared by the oil-in-oil solvent evaporation method. The drug was encapsulated into microspheres by an in situ method by varying the polymer contents. The resultant microspheres were characterized with respect to drug loading, flow properties, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffractometry (XRD), thermal analysis and release behavior. Chemically stable loaded microspheres were confirmed by FTIR, differential scanning calorimetry (DSC), thermogravimetric analysis and XRD. SEM images showed that the microspheres were spherical with smooth surfaces. FTIR spectra confirmed the presence of the drug in pure form and revealed no interaction between the drug and polymers. XRD and DSC were conducted to determine the nature of the drug in drug-loaded microspheres, and the results revealed that the drug was present in amorphous form. The maximum percentage entrapment efficiency was found to be 82 ± 2·11%, and the percentage yield was 89 ± 3·31%. The maximum in vitro drug release was more than 90% for pH 7·4, which demonstrated that drug-loaded formulations had a pH-dependent drug release. Cumulative drug release data were analyzed by using different kinetic models. The Korsmeyer–Peppas equation was used to determine the value of n which follows non-Fickian diffusion.

Influences of copolymers (Copovidone, Eudragit RL PO and Kollicoat MAE 30 DP) on stability and bioactivity of spray-dried and freeze-dried lysozyme

Protein stability is the most crucial factor in protein pharmaceutical preparations. Various techniques were applied for producing stable protein formulations such as spray-drying and freeze-drying. However, heating and freezing stresses are disadvantages for proteins using these methods, respectively. Accordingly, excipients have been used to preserve therapeutic effects of proteins during processing and for long period of time. Therefore, influences of Copovidone, Eudragit® RL-PO and Kollicoat® MAE-30 DP (as excipients) on stability and integrity of lysozyme (as a model protein) in spray-dried and freeze-dried forms were investigated. Protein formulations in both dried forms were prepared without and with the addition of mentioned excipients at different concentrations. Protein formulations were characterized for yield determination, morphology using scanning electron microscopic (SEM), thermal analysis by Differential Scanning Calorimetry (DSC), secondary structure stability using Fourier transform infrared (FT-IR) spectroscopy and biological activity. All protein formulations were subjected to a stability study as solid protein formulations for 3 weeks at 24 °C/76% relative humidity and aqueous protein samples were stored at 50 °C for 30 min in a water bath. Results showed that Copovidone successfully preserved integrity and biological activity of lysozyme before and after storage in both spray-dried and freeze-dried forms with more advantage for using higher concentration of the same excipient. Smooth spheres of spray-dried lysozyme formulations with Copovidone were smaller than spray-dried lysozyme without and with Kollicoat® MAE-30 DP, which affected %yield produced. Copovidone has demonstrated valuable protection ability for lysozyme.

Development and evaluation of colon targeted drug delivery system by using natural Polysaccharides/Polymers

Colon is being extensively investigated as a drug delivery site. This study contains comparison of the usual enteric coating polymers viz. xanthan gum, guar gum, chitosan and ethyl cellulose, as carriers for colon specific drug delivery. Lactose based metoprolol succinate tablets were prepared. These were coated with one of the coating polymers to a varying coat thickness. Tablets were prepared using polysaccharides or synthetic polymer as binders. These included xanthan gum, guar gum, chitosan and ethyl cellulose. Metoprolol Succinate was used as a model drug. The prepared tablets were enteric coated with kollicoat MAE 100 DP to give protection in the stomach. The coated tablets were tested in-vitro for their suitability as colon specific drug delivery systems. The drug release studies were carried out in simulated stomach environment (pH 1.2) for 2 h followed by small intestinal environment at pH 6.8. The dissolution data obtained from tablets demonstrates that the dissolution rate of the tablet is dependent upon the type and concentration of polysaccharide/polymer used as binder. The results demonstrate that enteric coated tablets containing 3% chitosan as a binder, showed only 12.5% drug release in the first 5 h, which is the usual upper gastrointestinal transit time, whereas, tablets prepared using guar gum as binder, were unable to protect drug release under similar conditions. Preparations with xanthan gum as a binder formed time-dependent release formulations. When used in a concentration of 5.92% in the tablets, 28% drug release was observed in the usual upper gastrointestinal tract conditions. It was also found that enteric coated preparation formulated with 8.88% of kollicoat MAE 100 DP as binder could be used to carry water insoluble drug molecules. The above study shows that chitosan could be successfully used as a binder, for colon targeting of water insoluble drugs in preference to guar gum when used in the same concentration. Additionally, formulations developed with chitosan and kollicoat MAE 100 DP would be highly site specific since drug release would be at a retarded rate till microbial degradation or polymer solubilization takes place in the colon. DOI: http://dx.doi.org/10.3329/dujps.v13i1.21874 Dhaka Univ. J. Pharm. Sci. 13(1): 105-113, 2014 (June)

Formulation and Evaluation of Enteric Coated SustainRelease Tablets of Lansoprazole in a ò-CyclodextrinComplex to Improve the Photostability

Enteric coated sustain release Lansoprazoletablets which are proton pump inhibitors in action, are widely used in the treatment of gastric ulcers. The aim of the present study is to improve photostabilityof Lansoprazole. Enteric Coated sustain release tablets of Lansoprazolewere formulates by using enteric polymers like Kollicoat MAE 30DP, and Eudragit L 100. Primary characterization of the drug was done by performing the melting point, identification test by Fourier Transform Infrared Spectroscopy, solubility and assay. To understand the compatibility of the drug with excipients, drug-excipient studies were carried out using Infrared spectroscopy. Using complexation technique different ratios of the drug were complexed with cyclodextrin to improve photostability. The stability test results indicated that the inclusion complex was more stable than raw Lansoprazole in the light. It was observed that inclusion complex of Lansoprazole showed increased the solubility by about 4.5 times. There were no significant differences between 30 min, 6 h and 24 h for either raw material or inclusion complex. Among the four polymers chitosan, xanthum gum, locust bean gum, and guar gum as polymers, chitosan was chosen for further coating process. Physico-chemical and in-vitro drug release studies were performed to all the formulations. F4c formulation was found to be best formulation which showed better resistance in 0.1N HCL, sustained well and with in-vitro release of97.83± 0.39% release in 12hrs.

Controlled Release of Tablets Containing Poorly Water Soluble Model Drug Coated with Kollicoat MAE 30DP

In this project we have prepared the tablets with a coating of pH-sensitive polymer Kollicoat MAE 30DP. For this purpose the core tablets prepared from poorly water soluble model drug and other excipients were coated by a fluidized bed apparatus at the exhaust air temperature of 30°C and spraying rate of 0.55 g/min. The highest coating time was 384 min which leads to the film thickness of 648 µm. The coated tablets were gastric resistant for one hour and resistant against intestinal fluid pH 6.8 up to 70 min. The coating film has a good quality with smoothness and dense packing. However, if the thickness was high e.g. 600 µm the film surface had more wavy structure. The results served to formulate the colon delivery system.

Evaluation of the drug release patterns and long term stability of aqueous and organic coated pellets by using blends of enteric and gastrointestinal insoluble polymers

The major aim of this study was to identify an efficient tool to adjust drug release patterns from aqueous and organic ethylcellulose (a gastrointestinal insoluble polymer) coated pellets and to evaluate the long term stability of the film coatings. Drug release was monitored during open and closed storage at 25 °C/60% RH (ambient conditions) and 40 °C/75% RH (stress conditions) for up to 24 months. Release of vatalanib succinate, a poorly soluble drug that demonstrates pH-dependent solubility, from pure ethylcellulose coated pellets was slow irrespectively of the type of coating and release medium. By addition of the enteric polymer methacrylic acid/ethyl acrylate copolymer (applied as aqueous Kollicoat MAE 30 DP dispersion or organic solution of Kollicoat MAE 100 P) to ethylcellulose broad ranges of drug release patterns could be achieved. For aqueous film coatings the addition of Kollicoat MAE 30 DP to ethylcellulose dispersions resulted in unaltered drug release kinetics during closed storage at ambient and stress conditions. The storage stabilizing effect of the added enteric polymer might be explained by the more hydrophilic nature of Kollicoat MAE 30 DP compared to ethylcellulose trapping water during film formation and improving polymer particle coalescence. However, during open storage of aqueous coated ethylcellulose:Kollicoat MAE 30 DP pellets at stress conditions drug release decreased due to further gradual polymer particle coalescence. In contrast, drug release rates from organic coated ethylcellulose:Kollicoat MAE 100 P pellets stored at ambient and stress conditions did not change which could be explained by differences in the film formation process. This clearly indicates that the presented concept of the addition of methacrylic acid/ethyl acrylate copolymer to ethylcellulose film coatings in combination with an organic coating process is able to achieve broad ranges of drug release patterns and to overcome storage instability.

Granulation by Roller Compaction and Enteric Coated Tablet Formulation of the Extract of the Seeds of Glinus Lotoides Loaded on Aeroperl® 300 Pharma

The purpose of this research was to improve the hygroscopicity and poor flow properties of the crude dry extract of the seeds of Glinus lotoides and improve the disintegration time of the core-tablets for enteric coated formulation thereof. The liquid crude extract of the plant was adsorbed on granulated colloidal silicon dioxide (Aeroperl 300 Pharma) at 30% w/w and the dry extract preparation (DEP) was dry-granulated with roller-compaction using Micro-Pactor. Hygroscopicity, flow property and disintegration time were improved significantly due to the adsorption and granulation processes. Moreover, the DEP does not become mucilaginous even at higher relative humidity levels (above 65%). Oblong tablets (20 x 8.25 mm) containing 947 mg of the granulated DEP (equivalent to the traditional dose), 363 mg of Avicel PH101 and 90 mg of Ac-di-Sol as disintegrant were formulated using an instrumented eccentric tablet machine at 20 kN. The tablets showed a crushing strength of 195 N, a friability of 0.4% and disintegrated within 9 min. The tablets were then enteric coated using polymethacrylate co-polymers (Eudragit L 100-55 and Kollicoat MAE 100P). The coated tablets resisted disintegration or softening in simulated gastric fluid for a minimum of 2 h and disintegrated within 15 min in intestine simulated fluid at pH 6.8. In addition to controlling the release of the active agents, the enteric coating improved the strength and decreased friability of the core-tablets.

Development of a novel osmotically driven drug delivery system for weakly basic drugs

The drug substance SAG/ZK has a short biological half-life and because of its weakly basic nature a strong pH-dependent solubility was observed. The aim of this study was to develop a controlled release (cr) multiple unit pellet formulation for SAG/ZK with pH-independent drug release. Pellets with a drug load of 60% were prepared by extrusion/spheronization followed by cr-film coating with an extended release polyvinyl acetate/polyvinyl pyrrolidone dispersion (Kollidon SR 30 D). To overcome the problem of pH-dependent drug release the pellets were then coated with a second layer of an enteric methacrylic acid and ethyl acrylate copolymer (Kollicoat MAE 30 DP). To increase the drug release rates from the double layered cr-pellets different osmotically active ionic (sodium and potassium chloride) and nonionic (sucrose) additives were incorporated into the pellet core. Drug release studies were performed in media of different osmotic pressure to clarify the main release mechanism. Extended release coated pellets of SAG/ZK demonstrated pH-dependent drug release. Applying a second enteric coat on top of the extended release film coat failed in order to achieve pH-independent drug release. Already low enteric polymer levels on top of the extended release coated pellets decreased drug release rates at pH 1 drastically, thus resulting in a reversal of the pH-dependency (faster release at pH 6.8 than in 0.1 N HCl). The addition of osmotically active ingredients (sodium and potassium chloride, and sucrose) increased the imbibing of aqueous fluids into the pellet cores thus providing a saturated drug solution inside the beads and increasing drug concentration gradients. In addition, for these pellets increased formation of pores and cracks in the polymer coating was observed. Hence drug release rates from double layered beads increased significantly. Therefore, pH-independent osmotically driven SAG/ZK release was achieved from pellets containing osmotically active ingredients and coated with an extended and enteric polymer. In contrast, with increasing osmotic pressure of the dissolution medium the in vitro drug release rates decreased significantly.

Electrophoretic properties of acrylic latex suspensions (Kollicoat ®MAE 30 D) and ibuprofen

We have compared the electrophoretic properties (measured on the electrical surface) of the commercial latex Kollicoat MAE 30 D and the non-steroidal anti-inflammatory drug (NSAID) ibuprofen in preparation for attempts to develop a suitable vehicle for the NSAID to obtain a modified release formulation. Electrophoretic mobility of the latex and the active principle was measured in solutions containing different concentrations of inorganic electrolytes (NaCl, CaCl 2 and AlCl 3) at different pH values. This was considered an indispensable first step for further characterization of the substance’s electrical properties. Suspensions of both the latex and the drug had negative mobility values throughout the range of pH values studied here. Of the electrolytes, neither NaCl nor CaCl 2 led to positive mobility, and no isoelectric point could be determined. However, AlCl 3 at a concentration of 10 –3 M led to the greatest reduction in mobility. We therefore found that trivalent cations were more effective than divalent cations, which in turn were more effective than monovalent cations, in reducing mobility.

Comparative Studies with Kollicoat MAE 30 D and Kollicoat MAE 30 DP in Aqueous Spray Dispersions and Enteric Coatings on Highly Swellable Caffeine Cores

A film formulation containing Kollicoat MAE 30 D, Kollidon 30, Sicovit Rot 30, titanium dioxide, talc, and a plasticizer for the aqueous manufacture of enteric coatings was studied for the coagulations occurring with certain plasticizers and for differences in resistance on highly swellable caffeine cores. Also included in these investigations were the latices Kollicoat MAE 30 DP and Eudragit L 30 D-55. The coagulations occurring with all three film latices can be attributed to the presence of Kollidon 30 together with certain excipients. Preparations with Kollidon 30, but without color pigments, showed no tendency to coagulate. The advantage of propylene glycol (PG) compared to other plasticizers such as triethyl citrate (TEC) is that no coagulations occurred, even in the presence of Kollidon 30 and color pigments. Among the Kollidon 30–free film formulations examined, a plasticizer content of 10–15% PG or TEC gave the best results. Optimal pigment distribution in the coat originally produced by Kollidon 30 can optionally be achieved by prolonged stirring of the pigment suspension. The resistance can be further improved by inclusion of a subcoating with Kollidon VA 64. Kollicoat MAE 30 D and MAE 30 DP and Eudragit L 30 D-55 showed identical behavior in this study.

Variation of Composition of an Enteric Formulation Based on Kollicoat MAE 30 D

Using a formulation described previously with Kollicoat MAE 30 D as the film-forming agent, the effect of variations in plasticizer type and quantity and talc concentration on the preparation and processing of spray-coating suspensions and the properties of isolated films and film-coated caffeine tablets prepared using them was investigated. In the preparation and processing of spray-coating suspensions, the plasticizers polyethylene glycol (PEG) 400, PEG1500, and TEC (triethyl citrate) tended to coagulate at all concentrations investigated, while Cremophor RH 40 coagulated above 10% (expressed as a percentage of the mass of the film-forming agent used). Analogous preparations using propylene glycol (PG), PEG6000, and Lutrol F 68, on the other hand, were found to be stable at all concentrations. The instability was not caused by the Kollicoat MAE 30 D polymer dispersion as such, but by interactions between the finely dispersed pigments and other formulation ingredients. Equivalent nonpigmented preparations are stable and do not coagulate. With all the plasticizers investigated, the minimum film-forming temperature (MFT) fell, albeit to differing degrees, as the amount of plasticizer increased. Similarly, the tensile strength of isolated films declined as plasticizer concentration increased, while the reverse was true as regards their elongation at break. Whereas neither the subsequent disintegration time nor the rate of release of active ingredient at pH 6.8 was significantly affected by the various plasticizer additives, the different film-coated tablet formulations with a core containing a powerful disintegrant exhibited varying degrees of permeability to simulated gastric fluid. With PEG6000, permeability increased as the plasticizer concentration increased, while Lutrol F 68 provided an optimum barrier at 20%, and PG provided a good barrier between 10% and 30%. No gastroresistance was obtained with TEC at 10%. Only the best plasticizer formulations were used in the trials with different talc concentrations, namely, those formulations with 20% PEG6000, 20% Lutrol F 68, 20% PG, and 10% PG. When talc was added, the MFT rose, reaching its maximum at 13% talc (as a proportion of the film-forming agent). In the test for gastroresistance, film-coated caffeine tablets without talc absorbed distinctly more acid than those containing talc. Above 27% talc, the acid resistance improved only insignificantly. On the other hand, during this test, only a maximum of 3% of the active ingredient was released into the gastric juice. Of the variants investigated, the formulation with 20% PG and 27% talc performed best.

Studies Comparing Kollicoat MAE 30 D with Commercial Cellulose Derivatives for Enteric Coating on Caffeine Cores

The products that are processed in aqueous form, such as Aqoat MF (suspension), Aquateric (pseudolatex), HP 55 (ammonia-based solution), and Kollicoat MAE 30 D (latex), were compared (in the form of spray dispersions, isolated films prepared from the dispersions, and caffeine-film-coated tablets with 5.5, 8.0, and 11.0 mg film/cm2) with one another and with ethanolic HP 55 S solution. The addition of pigments to all of the liquid preparations, with the exception of the ammoniacal solution of HP 55, led to a slight increase in pH. In each case, the viscosity of both solutions was well above that of the other formulations. The minimum film-forming temperature was decidedly reduced by the addition of pigment. Kollicoat MAE was the undissolved film-former that had the smallest particle size and particle size distribution. The next smallest were those of Aqoat MF. The latex and the suspension were the only products that were sensitive to shear and heat. The isolated films did not display any tack. The strongest films and the films most impermeable to water vapor were obtained from solutions, and this can be ascribed to the fine distribution of the film-former. None of the isolated films showed signs of dissolving at pH 4.5. At pH 5.5, only the HP 55 was dissolved. This was because HP 55 was processed in ammonia-based solution; as a result of which, films that were not very resistant to gastric juice were obtained. The other formulations did not dissolve until the pH reached 6.0. As the pH rose, the rate of dissolution increased for all of the films. The permeability to protons was similar to that of caffeine-film-coated tablets to gastric juice. The resistance increased in the following sequence: HP 55 (ammonia-based) < Aquateric < Aqoat MF < HP 55 S (organic) and Kollicoat MAE.