Lyophilized Drug-Loaded Solid Lipid Nanoparticles Formulated with Beeswax and Theobroma Oil

Solid lipid nanoparticles (SLNs) have the potential to enhance the systemic availability of an active pharmaceutical ingredient (API) or reduce its toxicity through uptake of the SLNs from the gastrointestinal tract or controlled release of the API, respectively. In both aspects, the responses of the lipid matrix to external challenges is crucial. Here, we evaluate the effects of lyophilization on key responses of 1:1 beeswax–theobroma oil matrix SLNs using three model drugs: amphotericin B (AMB), paracetamol (PAR), and sulfasalazine (SSZ). Fresh SLNs were stable with sizes ranging between 206.5–236.9 nm. Lyophilization and storage for 24 months (4–8 °C) caused a 1.6- and 1.5-fold increase in size, respectively, in all three SLNs. Zeta potential was >60 mV in fresh, stored, and lyophilized SLNs, indicating good colloidal stability. Drug release was not significantly affected by lyophilization up to 8 h. Drug release percentages at end time were 11.8 ± 0.4, 65.9 ± 0.04, and 31.4 ± 1.95% from fresh AMB-SLNs, PAR-SLNs, and SSZ-SLNs, respectively, and 11.4 ± 0.4, 76.04 ± 0.21, and 31.6 ± 0.33% from lyophilized SLNs, respectively. Thus, rate of release is dependent on API solubility (AMB < SSZ < PAR). Drug release from each matrix followed the Higuchi model and was not affected by lyophilization. The above SLNs show potential for use in delivering hydrophilic and lipophilic drugs.

EQUIVALENCE STUDY OF IMMEDIATE RELEASE TABLETS OF BETA BLOCKER DRUG

Objective: The therapeutic equivalence of generic brands is a great challenge for manufacturers. This study aimed to evaluate the bioequivalence of four different generic brands of atenolol tablets under biowaiver conditions. Methods: Physiochemical properties of the tablet products namely uniformity of weight, hardness, disintegration, and drug content were assessed. The dissolution profiles of atenolol tablets were conducted in pH 1.2, 4.5, 6.8 and 7.6 buffers using USP dissolution apparatus II. Similarity and difference factors were calculated. Finally, four kinetic models have been offered to describe the release characteristics of atenolol under experiment conditions. Results: All tablets showed accepted physiochemical characters. Dissolution profiles revealed that G2 showed the highest similarity to innovator (f2 91.86) in pH 7.6. Dissolution kinetics of G2 at the same pH could be best described as Higuchi model of release. Conclusion: The study showed that excipients and manufacturing practices play an important role in marketing biowaiver generic products meet the international regulatory bodies criteria.

Controlled Release of Model Substances from pH-Sensitive Hydrogels

pH-Sensitive hydrogels of the poly(methacrylic acid-comethyl methacrylate) (MAA/MMA) type, 22/78 molar % with different cross-linking percentages (0.3 and 0.5%) were synthesized. These gels were loaded with a model hydrophilic compound (dichlorobromophenol blue dye, DCBFB) with the aim of evaluating its release at different pH values (1.2, 5.0, 6.8, 7.4). The swelling degree and the release from these hydrogels are highly dependent on the pH of the dissolution medium and on the cross-linking degree. Scanning electron microscopy and differential scanning calorimetry studies demonstrated that part of the dye is embedded in crystal form within the hydrogel. The release profiles of the hydrogels assessed at pH = 6.8 and 7.4 were adjusted to the Higuchi model, regarding them asmatrix delivery systems.

Formulation and evaluation of nanoparticulate ofloxacin ophthalmic gel using ionic gelation method

Oflaxacin is an ophthalmic and topical anti-bacterial agent used in the management of Allergic conjunctivitis, Trachoma, Blepharitis. The basic idea behind the development of such a system is to maintain a sustained drug release from the dosage form. Oflaxacin is suitable candidate for formulation into sustained dosage form in order to prolong the release of drug. The drug-excipient compatibility studies were carried out by using FTIR technique. Based on the results, excipients were found to be compatible with ofloxacin. In preformulation study, estimation of Ofloxacin was carried out by systronics UV spectrophotometer at λmax 284nm using distilled water, which had a good reproducibility and this method was used in entire study. Formulation was prepared by using ionic gelation method .The response drug content, entrapment efficiency, diffusion, spreadability, In vitro drug release was evaluated Drug content ranging from to 82.6 % to 91.24% entrapment efficiency values are ranged from 91.25% to 94.02% and in -vitro drug release studies are also studied. The In-vitro drug release study of Ofloxacin was carried out by using In-vitro diffusion apparatus.100ml of using tear fluid was taken in a beaker. The solution was stirred with 100rpm by maintaining the temperature of 37˚c ± 5˚c. The drug release data were explored for this type of release mechanism followed. The best fit with the highest determination R2 coefficients was shown by both the models (zero and peppas) followed by Higuchi model which indicate the drug release via diffusion mechanism. However as indicated by the values of R both of the models (zero and peppas) followed by Higuchi model were found to be efficient in describing the release of Ofloxacin.

Formulation, Development and Evaluation of Bilayer Tablet of Flurbiprofen

In the Study of Formulation of Bilayer Tablet of Flurbiprofen the Following Materials Using sodium starch glycolate as immediate release and HPMC K15 in different ratios as release retardant materials using a wet granulation method. All tablets exhibited good physical properties with Respect to appearance, content uniformity, hardness, weight variation and Invitro dissolution data show at increasing proportions Of sodium starch glycolate for immediate release whereas HPMC K15sustaineddrugreleaserate. The bilayer tablets showed an initial release of drug In about1hr, then sustaining the release for 12h, The kinetic analysis of dissolution data showed that release was observe din these tablets. When data was fitted to the Higuchi model. Bilayer tablets of flurbiprofen can be successfully formulated Using sodium starch glycolate and HPMC K15 in different ratios as release retardant materials employing a wet granulation method.

Acetylsalicylic Acid (ASA) on Hydroxyethylcellulose/Polyacrylamide Gel (HEC/PAAm) as a Proposal for a Dermatological Compress: Mathematical Modeling of ASA Release Kinetics

Currently, acne in adolescents and adults is caused by an infection in follicles caused by hormonal changes, stress, water pollution, air, and earth; the last one comes into contact with the skin through the hands of patients. This project presents the incorporation of acetylsalicylic acid (ASA) to the hydroxyethylcellulose/polyacrylamide gel (HEC/PAAm) in the synthesis of gel or by its swelling. The results show us that the incorporation of ASA is possible by both methods; first, the incorporation by synthesis of degradation of the gel is more visible. The infrared spectroscopic analysis shows the functional groups of gel and ASA, 2921 and 2863 cm−1, whose assignments correspond to CH3 and CH2 groups, which are part of both the polymer and the ASA molecule, which confirms the interaction between the two groups. The microscopy photographs (SEM) show on the surface the drug in irregular whitish orthorhombic forms due to swelling; arborescent structures are observed in the case of the incorporation of the ASA drug by synthesis. Swelling kinetics has a Fickian form. The Higuchi model conforms to the release of ASA because the level of confidence is 90%. This gel was allowed to release 0.35 mg/hour, thus allowing the patient to have a continuous form of the release, in the affected area in a short period of time.

Formulation and Evaluation of Sustained Release Floating Tablets of an Antihypertensive Diltiazem

The aim of the present study was to develop and evaluate sustained release floating tablets of Diltiazem hydro-chloride, an antihypertensive agent. The sustained release floating tablets were prepared by direct compression method and formulated using different polymer combinations, formulations such as F1 to F9. Natural polymer Sodium alginate and synthetic polymer HPMC K4M were used. Developed formulations were evaluated for the pre compression parameters i.e., drug- excipients compatibility by FTIR, bulk density, compressibility, and angle of repose etc. Post compression parameters i.e. weight variation; full factorial design was applied to optimize the developed formulation. SA and HPMC K4M were selected as independent variable at three different concentrations. The in-vitro drug release study revealed that formulation F8 combination of both synthetic (HPMC) and natural polymers (sodium alginate) was the most successful formulation of the study, all tablets but one exhibited gradual and near complete sustained release for diltiazem HCl (90-100%) that extended the drug release up to 8 hours, with satisfactory drug release in the initial hours, and the total release pattern was close to the theoretical release profile. Model equations of zero and first order, Higuchi, Hixson-Crowell and Peppas, intended to elucidate the drug release mechanism, and were fitted to the release data. Mathematical modelling of in-vitro dissolution data indicated the best-fit release kinetics was achieved with Higuchi model with r2 vales of 0.994 in its semi log plot. The ‘n’ value in Higuchi model was >0.89 which indicated, Super Case-II transport of drug from polymer sustained, i.e., diffusion with relaxation of polymeric chain. In conclusion, the results indicated that the prepared sustained-release tablets of Diltiazem hydrochloride could perform therapeutically better than conventional tablets with improved efficacy and better patient compliance.

Effect of cellulose acetate phthalate and polyethylene glycol on physical properties and release of theophylline from microcapsules

ABSTRACT The present study describes the development of theophylline microcapsules by a non-solvent addition method and the effect of plasticizer addition on microencapsulation. The release was studied in distilled water and the data were analysed by various mathematical models for determining the mechanism of release. Prepared microcapsules were found to be spherical, free flowing and having more than 80% entrapped drug. The polymer - cellulose acetate phthalate and plasticizer - polyethylene glycol was considered to be affecting the properties of microcapsules including drug release (time for 50% drug release, T50). The formulation with the highest proportion of polymer and without plasticizer (F3) showed the slowest release with T50 = 4.3 h, while the formulation with lower proportion of polymer and 20% (w/w) plasticizer (F13 &14) showed the fastest release of drug with T50 values of 1.2 h and 1.3 h, respectively. The drug release from most of the formulations was found to be following Higuchi model. It is concluded from the results of the present study that cellulose acetate phthalate significantly affects the sustained release of the drug in water, whereas the addition of polyethylene glycol slightly enhances the drug release.