Formulation Development and Evaluation of Emulgel of Clindamycin Phosphate for Effective Treatment of Acne

Emulgel have emerged as one of the most interesting topical delivery system as it has dual release control system i.e. gel and emulsion. The topical applications of the drug offers the potential advantages of delivering the drug directly to the site of action and delivering the drug for extended period of time at the effected site that mainly acts at the related regions. The major objective behind this formulation is enhancing the topical delivery of hydrophobic drug (clindamycin phosphate) by formulating clindamycin phosphate emulgel using carbopol 941 as a gelling agent. In addition, light liquid paraffin as oil, tween-20 and span-20 as emulsifiers and propylene glycol as co-surfactant were selected for preparation of emulgel. Clindamycin phosphate is an antibiotic useful for the treatment of a number of infections. It is of the lincosamide class. Clindamycin phosphate is a semi synthetic lincosamide antibiotic that has largely replaced lincomycin due to an improved side effect profile. Clindamycin inhibits bacterial protein synthesis by binding to bacterial 50S ribosomal subunits. Topical clindamycin phosphate reduces free fatty acid concentrations on the skin and suppresses the growth of Propionibacterium acnes (Corynebacterium acnes), an anaerobe found in sebaceous glands and follicles.  The prepared emulgel were evaluated for their physical appearance, pH determination, viscosity, spreadability, extrudability, in vitro drug release, anti acne activity and stability. All the prepared emulgel showed acceptable physical properties, homogeneity, consistency, spreadability, viscosity and pH value. The best formulation F4 showed better antiacne activity when compared with all formulation. Keywords: Emulgel, Clindamycin phosphate, Extrudability, Spreadability, Antiacne activit

FORMULATION AND EVALUATION OF GEL CONTAINING ETHOSOMES ENTRAPPED WITH TRETINOIN

A skin disease, like acne, is very common and normally happens to everyone at least once in their lifetime. The structure of the stratum corneum is often compared with a brick wall, with corneocytes surrounded by the mortar of the intercellular lipid lamellae. One of the best options for successful drug delivery to the affected area of skin is the use of ethosomes which can be transported through the skin through channel-like structures. Tretinoin is a widely used retinoid for the topical treatment of acne, photo-aged skin, psoriasis and skin cancer which makes it a good candidate for topical formulation. Yet side effects, like redness, swelling, peeling, blistering and, erythema, in addition to its high lipophilicity make this challenging. Drug loaded ethosomes had been prepared using phospholipid and ethanol, were optimized and characterized for entrapment efficiency, vesicular size, shape, In-vitro skin permeation, skin retention, drug‐membrane component interaction and stability. The ethosomal formulation having 0.5 %w/v of phospholipid and 20 %v/v of ethanol (F2) showing the greatest entrapment efficiency (80.25±0.23) with small particle size (205.40±2.31nm) was selected for further skin permeation studies. The skin permeation and skin retention studies were performed on ethosomal formulation, liposomal formulation (0.5 %w/v of phospholipid without alcohol), hydroethanolic drug solution and phosphate buffer saline (pH7.4) drug solution. Among them, ethosomal formulation showed higher cumulative percentage of drug permeation (93.36±0.45%) and 8 hours than the other formulations. Scanning electron microscopy confirmed the three dimensional nature of ethosomes. Dynamic light scattering technique proved that the ethosomes has smaller vesicular size than the liposomes prepared without alcohol. FT‐IR studies revealed no interaction between the drug and membrane components. The ethosomal vesicles were incorporated in carbopol gel base and its anti‐acne was compared with the marketed gel. Our results suggest that the ethosomes are an efficient carrier for dermal and transdermal delivery of tretinoin. Keywords: Tretinoin, Ethosomes, Diffusion, Carbopol gels, Transdermal delivery

Formulation Development and Evaluation of Sustain Release Gastroretentive Floating Tablets of Prochlorperazine Dimaleate

Floating drug delivery systems are the gastroretentive forms that precisely control the release rate of target drug to a specific site which facilitate an enormous impact on health care. The purpose of this research was to develop a novel gastro retentive drug delivery system based on direct compression method for sustained delivery of active agent to improve the bioavailability, reduce the number of doses and to increase patient compliance. Gastro retentive floating tablets of Prochlorperazine dimaleate (PCZ) were prepared by direct compression method using altered concentrations of HPMC K4, HPMC K15 and PVP K30 as polymers. The prepared tablets of PCZ were evaluated for hardness, thickness, friability, weight variation, drug content uniformity, buoyancy lag time, total floating time, in-vitro dissolution study, etc. All the compositions were resulted in adequate Pharmacopoeial limits. Compatibility studies was execution during FTIR shown that there was absence of probable chemical interaction between pure drug and excipients. The varying concentration of gas generating agent and polymers was found to affect on in-vitro drug release and floating lag time. In vitro drug release of floating gastro retentive tablet of PCZ shown that the formulation F9 was found to be the best formulation as it releases 98.89% in a controlled manner for an extended period of time (up to 12 hrs). The release data was fitted to various mathematical models such as Higuchi, Korsmeyer-Peppas, First order and Zero order to evaluate the kinetics and mechanism of the drug release. The optimized formulation (F9) showed no significant change in physical appearance, drug content, floating lag time, in vitro dissolution studies after 75%±5% RH at 40±20C relative humidity for 6 months.  Prepared floating tablets of PCZ may prove to be a potential candidate for safe and effective controlled drug delivery over an extended period of time for gastro retentive drug delivery system. Keywords: Prochlorperazine dimaleate, Floating tablet, Gastro retentive, Total floating time