Last updated: August 2, 2026
MICRO-K 10 is a legacy prescription potassium chloride extended-release capsule containing 10 mEq, equivalent to 750 mg potassium chloride. Its commercial position is shaped by generic substitution, low-cost active pharmaceutical ingredient supply, limited formulation differentiation and long-expired core intellectual property. No reliable public source discloses standalone MICRO-K 10 revenue, profit or prescription volume. The product’s financial trajectory is therefore best assessed through market structure, reimbursement, supply conditions and brand-versus-generic positioning rather than reported product sales.
What is MICRO-K 10 and what market does it serve?
MICRO-K 10 is an oral potassium replacement product used to treat or prevent hypokalemia. The product uses extended-release potassium chloride capsules, commonly described as MICRO-K Extencaps. Each capsule provides 10 mEq of potassium chloride.[1]
Potassium chloride products are used in patients whose potassium depletion results from:
- Diuretic therapy
- Gastrointestinal potassium loss
- Renal potassium wasting
- Certain endocrine or metabolic disorders
- Chronic conditions requiring potassium replacement
The relevant market is not a single-drug market. It includes:
- Extended-release potassium chloride tablets
- Extended-release capsules
- Liquid potassium chloride
- Powder or solution packets
- Intravenous potassium chloride
- Combination products containing a diuretic and potassium supplementation
The main substitutes are generic potassium chloride extended-release tablets and capsules. Dosage form, swallowing ability, gastrointestinal tolerability, pharmacy availability and payer formulary rules influence product selection.
What is the FDA regulatory status of MICRO-K 10?
MICRO-K 10 is an FDA-approved prescription potassium chloride extended-release product associated with NDA 018239 in FDA product records.[2] The product is regulated as a drug rather than as a biologic, so biosimilar competition is not relevant.
The product’s regulatory profile has several commercial implications:
| Regulatory factor |
MICRO-K 10 position |
| Active ingredient |
Potassium chloride |
| Strength |
10 mEq per capsule |
| Dosage form |
Extended-release capsule |
| Route |
Oral |
| FDA pathway |
Original NDA and subsequent generic ANDA competition |
| Biologic status |
Not applicable |
| Pediatric exclusivity |
No current product-specific exclusivity identified |
| NCE exclusivity |
No current NCE exclusivity |
| Commercial category |
Legacy prescription electrolyte replacement |
Potassium chloride extended-release products carry important administration and safety requirements. Capsules must be swallowed whole, and extended-release products are not interchangeable with every liquid, immediate-release or intravenous formulation on a simple milligram-for-milligram basis. The FDA label warns about gastrointestinal injury, hyperkalemia and clinically significant drug interactions.[1]
When does MICRO-K 10 lose exclusivity?
MICRO-K 10’s core regulatory exclusivity expired long ago. The product is a legacy small-molecule medicine and does not have current new chemical entity exclusivity, orphan-drug exclusivity or biologic reference-product exclusivity.
The commercial consequence is that competitors can rely on the established active ingredient and seek approval through the FDA abbreviated new drug application pathway. Generic applicants generally must demonstrate pharmaceutical equivalence and bioequivalence rather than repeat the full clinical development program required for an original NDA.[3]
No remaining regulatory exclusivity appears to prevent generic competition in the 10 mEq extended-release potassium chloride category. Any remaining commercial protection would depend on product-specific patents, manufacturing know-how, distribution contracts, trademarks or supply reliability rather than market exclusivity.
What patents protect MICRO-K 10?
The original extended-release potassium chloride technology associated with MICRO-K 10 is legacy intellectual property. Any patents covering the basic potassium chloride extended-release capsule concept would have expired after the standard patent term.
A current FDA Orange Book review is the relevant source for listed patents and regulatory exclusivity. The Orange Book does not provide a basis for treating MICRO-K 10 as a currently patent-protected product with a blocking patent estate.[4]
| IP category |
Current assessment |
| Active-ingredient patent |
Expired or unavailable for current blocking protection |
| Original formulation patent |
Legacy protection; expected to be expired |
| Method-of-use patent |
No current blocking protection identified |
| Manufacturing patent |
Potential know-how may exist, but no public evidence establishes a blocking patent |
| Orange Book patent barrier |
No material current barrier identified |
| Trademark |
Brand recognition may remain, but trademark rights do not prevent generic potassium chloride |
The absence of a current Orange Book patent barrier materially reduces litigation risk. It also limits the ability of a brand owner to preserve premium pricing through patent enforcement.
What is the Orange Book status of MICRO-K 10?
MICRO-K 10 should be analyzed as an older approved prescription product with generic competition rather than as a late-life branded medicine protected by listed patents.
The Orange Book distinguishes approved reference products from patent-listed products. An NDA can remain historically important as a reference product even when it has no active patent or exclusivity protection. Generic applicants can reference the approved product if they meet FDA requirements for the relevant dosage form and strength.[4]
For commercial diligence, the key Orange Book questions are:
- Whether the NDA remains active or is listed as discontinued.
- Whether the specific 10 mEq capsule strength has approved ANDA competitors.
- Whether any patents are listed against the reference product.
- Whether FDA has determined the reference product was withdrawn for safety or effectiveness reasons.
A discontinued marketing status does not, by itself, establish that the active ingredient or dosage form is unavailable. Other potassium chloride products can continue to serve the same clinical need.
How many patents cover MICRO-K 10?
No meaningful current patent estate is apparent for MICRO-K 10. The relevant protection is likely limited to expired historical patents, process knowledge and brand-related commercial rights.
This distinction matters. A legacy drug can have manufacturing complexity without having enforceable patent exclusivity. Extended-release potassium chloride manufacturing may require control of particle size, coating, release kinetics, capsule fill uniformity and dissolution performance. Those technical requirements can raise entry costs, but they do not necessarily create a patent barrier.
The practical IP position is therefore:
- Low patent litigation exposure
- Low probability of a successful patent-based generic delay
- Limited value from patent licensing
- Greater importance of manufacturing validation and regulatory compliance
- Greater exposure to price competition
Which companies compete with MICRO-K 10?
Competition comes primarily from generic manufacturers and from branded or authorized-generic potassium chloride products. The relevant competitor set can change as manufacturers enter or leave the market.
Typical competing products include:
- Generic potassium chloride extended-release tablets
- Generic potassium chloride extended-release capsules
- Klor-Con or equivalent potassium chloride products
- Micro-K-equivalent capsule products
- Potassium chloride oral solutions
- Potassium chloride powder products
The principal competitive variables are price, wholesaler availability, pharmacy substitution, formulary placement and shortage performance. Clinical differentiation is limited because the products deliver the same electrolyte, although release characteristics and dosage forms can affect tolerability and adherence.
Tablet products may have greater volume because they are widely dispensed and often available from multiple manufacturers. Capsules can retain a niche among patients who cannot tolerate or swallow certain tablet products, but this niche is insufficient to create durable pricing power when generic capsule alternatives are available.
What formulations are protected by MICRO-K 10?
MICRO-K 10 is associated with an extended-release capsule formulation. Its commercial relevance depends on the delivery system rather than on a novel active ingredient.
The formulation must manage the local concentration of potassium chloride in the gastrointestinal tract. Concentrated solid potassium chloride can cause gastrointestinal irritation or ulceration, which is why extended-release design, dosing instructions and administration with meals are clinically relevant.[1]
Potentially differentiating formulation characteristics include:
- Capsule versus tablet presentation
- Extended-release profile
- Dissolution behavior
- Particle or crystal structure
- Coating technology
- Capsule size
- Ease of swallowing
- Tolerability in chronic use
There is no clear evidence that these characteristics remain protected by active patents for MICRO-K 10. They can still create manufacturing and regulatory barriers, particularly where a generic applicant must demonstrate bioequivalence and acceptable dissolution performance.
Are there Paragraph IV challenges or patent lawsuits involving MICRO-K 10?
No prominent current Paragraph IV campaign or material patent litigation is associated publicly with MICRO-K 10. That outcome is consistent with the product’s age and the apparent absence of a blocking patent estate.
A Paragraph IV certification challenges the validity, enforceability or applicability of a listed patent. It is commercially important for newer drugs because it can delay generic launch and trigger Hatch-Waxman litigation. For MICRO-K 10, the absence of meaningful listed patent protection reduces the likelihood that a Paragraph IV challenge would be the central route to market entry.[3]
The principal legal risks are more likely to involve:
- Product liability
- Manufacturing deviations
- Labeling disputes
- Supply contracts
- Trademark or trade-dress issues
- Pharmacy substitution and reimbursement disputes
No material settlement agreement is publicly associated with a current MICRO-K 10 patent dispute. The lack of settlement activity reinforces the conclusion that the product is not supported by an active patent-based exclusivity strategy.
What is the generic entry risk for MICRO-K 10?
Generic entry risk is high because the product has:
- An old active ingredient.
- No apparent current regulatory exclusivity.
- No material listed patent barrier.
- Established clinical use.
- Multiple substitute dosage forms.
- A relatively straightforward oral solid-dose manufacturing pathway compared with complex biologics.
The main constraint is not legal entry. It is commercial attractiveness. Potassium chloride products generally have low unit prices and limited differentiation. Some manufacturers may avoid the market if expected gross margins do not cover manufacturing, quality, distribution and shortage-management costs.
Generic entry can still produce meaningful price erosion even when only a few suppliers remain. Pharmacy benefit managers, wholesalers and retail chains typically favor low-cost interchangeable products. Brand retention depends on prescriber familiarity, patient preference, pharmacy availability or an authorized-generic strategy.
How does MICRO-K 10 compare with competing potassium chloride products?
| Product characteristic |
MICRO-K 10 |
Generic ER tablet |
Oral liquid or powder |
Intravenous potassium chloride |
| Active ingredient |
Potassium chloride |
Potassium chloride |
Potassium chloride |
Potassium chloride |
| Typical use |
Chronic oral replacement |
Chronic oral replacement |
Patients needing flexible dosing |
Acute or inpatient replacement |
| Administration |
Oral capsule |
Oral tablet |
Oral liquid or dissolved product |
Hospital infusion |
| Patent position |
Legacy, no material current barrier |
Generally unprotected active ingredient |
Generally unprotected |
Generally unprotected |
| Main advantage |
Capsule dosage form and brand familiarity |
Low price and broad availability |
Flexible dosing |
Rapid controlled hospital use |
| Main limitation |
Generic substitution and low differentiation |
Tolerability and swallowing issues |
Taste, dosing complexity |
Monitoring and hospital administration |
MICRO-K 10’s strongest commercial defense is dosage-form familiarity. Its weakest point is the availability of therapeutically similar low-cost alternatives.
What is the financial trajectory for MICRO-K 10?
No audited standalone revenue or profit figures are publicly reported for MICRO-K 10. The product should therefore be modeled as a mature, low-growth prescription asset rather than a separately disclosed growth franchise.
The likely financial trajectory has four phases:
| Period |
Commercial pattern |
Financial implication |
| Original launch and early adoption |
Brand establishes clinical use |
Higher pricing and brand contribution |
| Generic entry |
ANDA competitors enter |
Rapid price and share erosion |
| Mature generic market |
Stable demand, low unit economics |
Revenue depends on volume and supply |
| Late-life supply market |
Manufacturer exits or shortages may occur |
Temporary price spikes and uneven revenue |
Revenue is likely influenced more by product availability than by prescription growth. If a competitor experiences a shortage, MICRO-K 10 or another available product may capture temporary volume. That benefit is usually unstable because supply normalization and alternative dosage forms can reverse the gain.
A practical financial model should separate:
- Gross sales
- Net sales after rebates and wholesaler discounts
- Capsule volume
- Average selling price
- Generic substitution rate
- Cost of goods
- Quality and compliance costs
- Distribution fees
- Inventory write-offs
- Shortage-related price effects
The base case is low single-digit or negative long-term revenue growth in a normal-supply environment. Upside would come from competitor shortages, renewed brand distribution, limited capsule competition or a favorable reimbursement position. Downside would come from new generic entrants, manufacturer discontinuation, reimbursement compression or production interruption.
What manufacturing and supply barriers affect MICRO-K 10?
Manufacturing barriers are moderate rather than severe. Potassium chloride is a mature, widely available active ingredient, but extended-release oral products require validated control over release characteristics and gastrointestinal tolerability.
Key manufacturing risks include:
- API particle-size variability
- Capsule-fill uniformity
- Dissolution and release-rate failure
- Moisture control
- Packaging stability
- Batch-to-batch potency variation
- Quality-system deficiencies
- Reliance on a limited number of API or contract-manufacturing suppliers
These barriers can reduce the number of reliable suppliers even when regulatory entry is legally open. They may also cause intermittent shortages or product withdrawals. Supply resilience can therefore create more commercial value than patent ownership.
What licensing deals affect MICRO-K 10?
No major recent licensing transaction is publicly associated with MICRO-K 10. Legacy products may move between manufacturers, marketing partners or distributors without generating a separately disclosed transaction value.
Any potential licensing value would likely relate to:
- Brand and trademark rights
- Existing NDA ownership
- Manufacturing and packaging rights
- Authorized-generic arrangements
- Distribution access
- Transfer of regulatory files
The absence of a current patent estate limits the value of an IP-only license. A transaction would be more likely to reflect supply capability, regulatory ownership or commercial distribution than exclusive technology.
What are the geographic market opportunities?
The strongest commercial opportunity is in the United States prescription market, where FDA-approved potassium chloride products are dispensed through retail, mail-order and institutional channels.
International opportunities depend on local registrations and may not use the MICRO-K 10 brand. The underlying product is a global electrolyte replacement category, but national markets differ in:
- Prescription requirements
- Approved strengths
- Capsule and tablet availability
- Reimbursement
- Local generic competition
- Product naming
- Pharmacovigilance obligations
Geographic expansion would likely require regulatory filings and local distribution rather than patent licensing. Because potassium chloride is a mature product, the commercial case depends on reliable supply and low operating cost.
What is the competitive outlook for MICRO-K 10?
The competitive outlook is stable but unattractive for premium pricing. Demand for potassium replacement should remain durable because diuretic use, chronic disease and hospital-to-outpatient transitions sustain the underlying need. Product-level growth is constrained by therapeutic substitutability and generic reimbursement pressure.
The most probable outcomes are:
- Continued generic substitution
- Low or declining average selling prices
- Periodic volume shifts caused by shortages
- Limited value from patent enforcement
- Stable but modest demand for oral extended-release potassium
- Greater importance of manufacturing efficiency and distribution
Key Takeaways
- MICRO-K 10 is a legacy 10 mEq extended-release potassium chloride capsule.
- Its active ingredient and core formulation technology do not provide meaningful current exclusivity.
- No material current Orange Book patent barrier or prominent Paragraph IV litigation is associated with the product.
- Biosimilar risk does not apply because potassium chloride is a small-molecule drug.
- Generic potassium chloride tablets and capsules are the principal competitive threat.
- No reliable standalone revenue or profit data is publicly disclosed.
- The financial trajectory is likely mature to declining, with temporary upside during competitor shortages.
- Manufacturing reliability, regulatory compliance and pharmacy availability matter more than patent strength.
- Licensing value would likely arise from NDA ownership, brand rights or supply capability rather than patent exclusivity.
- The product has durable clinical demand but limited pricing power.
FAQs
Is MICRO-K 10 still a branded drug?
MICRO-K 10 is a legacy branded potassium chloride product, but its market position is exposed to generic substitution. Brand status does not create current exclusivity.
Is MICRO-K 10 interchangeable with Klor-Con?
Interchangeability depends on the specific dosage form, strength, release characteristics and state substitution rules. A pharmacist should use the approved product-equivalence designation and prescription requirements for the relevant product.
Can a generic manufacturer launch potassium chloride 10 mEq capsules?
Yes. A generic manufacturer can pursue FDA approval through the ANDA pathway if it meets applicable pharmaceutical-equivalence, bioequivalence, quality and labeling requirements.
Does MICRO-K 10 have orphan-drug protection?
No current orphan-drug exclusivity is associated with MICRO-K 10. Potassium chloride is used for broad electrolyte replacement indications rather than a narrowly defined rare disease indication.
What would increase the value of the MICRO-K 10 business?
The most credible value drivers are reliable supply, strong pharmacy distribution, an established NDA, low manufacturing cost, shortage-driven demand and a defensible capsule presentation. Patent-based value is limited.
References
- U.S. National Library of Medicine. (n.d.). Micro-K Extencaps: Potassium chloride extended-release capsules, USP prescribing information. DailyMed.
- U.S. Food and Drug Administration. (n.d.). Drugs@FDA: FDA-approved drugs, NDA 018239.
- U.S. Food and Drug Administration. (n.d.). Abbreviated new drug application process for generic drugs.
- U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations, Orange Book.
